From: spo <sergey.pokhodenko@opencascade.com>
Date: Thu, 23 Jun 2016 14:33:12 +0000 (+0300)
Subject: Validators return InfoMessage instead of string as an error
X-Git-Tag: V_2.4.0~20
X-Git-Url: http://git.salome-platform.org/gitweb/?a=commitdiff_plain;h=7e9e955376b504dc7d9e0a5e79a9a38943a53fcd;p=modules%2Fshaper.git

Validators return InfoMessage instead of string as an error
---

diff --git a/src/BuildPlugin/BuildPlugin_Validators.cpp b/src/BuildPlugin/BuildPlugin_Validators.cpp
index 234e697b2..9c2be0bae 100644
--- a/src/BuildPlugin/BuildPlugin_Validators.cpp
+++ b/src/BuildPlugin/BuildPlugin_Validators.cpp
@@ -28,7 +28,7 @@
 //=================================================================================================
 bool BuildPlugin_ValidatorBaseForBuild::isValid(const AttributePtr& theAttribute,
                                                 const std::list<std::string>& theArguments,
-                                                std::string& theError) const
+                                                Events_InfoMessage& theError) const
 {
   // Get base objects list.
   if(theAttribute->attributeType() != ModelAPI_AttributeSelectionList::typeId()) {
@@ -109,7 +109,7 @@ bool BuildPlugin_ValidatorBaseForBuild::isValid(const AttributePtr& theAttribute
 //=================================================================================================
 bool BuildPlugin_ValidatorBaseForWire::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                                const std::list<std::string>& theArguments,
-                                               std::string& theError) const
+                                               Events_InfoMessage& theError) const
 {
   // Get attribute.
   if(theArguments.size() != 1) {
@@ -154,7 +154,7 @@ bool BuildPlugin_ValidatorBaseForWire::isNotObligatory(std::string theFeature, s
 //=================================================================================================
 bool BuildPlugin_ValidatorBaseForFace::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                                const std::list<std::string>& theArguments,
-                                               std::string& theError) const
+                                               Events_InfoMessage& theError) const
 {
   // Get attribute.
   if(theArguments.size() != 1) {
@@ -229,7 +229,7 @@ bool BuildPlugin_ValidatorBaseForFace::isNotObligatory(std::string theFeature, s
 //=================================================================================================
 bool BuildPlugin_ValidatorSubShapesSelection::isValid(const AttributePtr& theAttribute,
                                                       const std::list<std::string>& theArguments,
-                                                      std::string& theError) const
+                                                      Events_InfoMessage& theError) const
 {
   if(theArguments.size() != 1) {
     std::string aMsg = "Error: BuildPlugin_ValidatorSubShapesSelection should be used only with "
diff --git a/src/BuildPlugin/BuildPlugin_Validators.h b/src/BuildPlugin/BuildPlugin_Validators.h
index 2bd253f9d..a72a882f1 100644
--- a/src/BuildPlugin/BuildPlugin_Validators.h
+++ b/src/BuildPlugin/BuildPlugin_Validators.h
@@ -23,7 +23,7 @@ public:
   //! \param[out] theError error message.
    virtual bool isValid(const AttributePtr& theAttribute,
                         const std::list<std::string>& theArguments,
-                        std::string& theError) const;
+                        Events_InfoMessage& theError) const;
 };
 
 /// \class BuildPlugin_ValidatorBaseForWire
@@ -39,7 +39,7 @@ public:
   //! \param theError error message.
   virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 
   /// \return true if the attribute in feature is not obligatory for the feature execution
   virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
@@ -58,7 +58,7 @@ public:
   //! \param theError error message.
   virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 
   /// \return true if the attribute in feature is not obligatory for the feature execution
   virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
@@ -76,7 +76,7 @@ public:
   //! \param[out] theError error message.
    virtual bool isValid(const AttributePtr& theAttribute,
                         const std::list<std::string>& theArguments,
-                        std::string& theError) const;
+                        Events_InfoMessage& theError) const;
 };
 
 #endif
diff --git a/src/Config/Config_Translator.cpp b/src/Config/Config_Translator.cpp
index 1210b2bbc..058acfca3 100644
--- a/src/Config/Config_Translator.cpp
+++ b/src/Config/Config_Translator.cpp
@@ -101,15 +101,14 @@ bool Config_Translator::load(const std::string& theFileName)
   return true;
 }
 
-std::string Config_Translator::translate(std::shared_ptr<Events_InfoMessage> theInfo)
+std::string Config_Translator::translate(const Events_InfoMessage& theInfo)
 {
-  std::string aContext = theInfo->context();
-  std::string aMessage = theInfo->messageString();
-  std::list<std::string> aParameters = theInfo->parameters();
+  std::string aContext = theInfo.context();
+  std::string aMessage = theInfo.messageString();
+  std::list<std::string> aParameters = theInfo.parameters();
   return translate(aContext, aMessage, aParameters);
 }
 
-
 std::string insertParameters(const std::string& theString, const std::list<std::string>& theParams)
 {
   std::string aResult = theString;
diff --git a/src/Config/Config_Translator.h b/src/Config/Config_Translator.h
index 6f79f81d1..158091be3 100644
--- a/src/Config/Config_Translator.h
+++ b/src/Config/Config_Translator.h
@@ -40,11 +40,11 @@ public:
 
   /**
   * Returns translation from the given info message.
-  * If transdlation is not exists then it returns a string 
+  * If translation is not exists then it returns a string
   * from the info data without translation
   * \param theInfo an info message
   */
-  static CONFIG_EXPORT std::string translate(std::shared_ptr<Events_InfoMessage> theInfo);
+  static CONFIG_EXPORT std::string translate(const Events_InfoMessage& theInfo);
 
   /**
   * Returns translation from the given data.
@@ -86,4 +86,4 @@ private:
 #endif
 };
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/Events/Events_InfoMessage.h b/src/Events/Events_InfoMessage.h
index 959001c43..2924df181 100644
--- a/src/Events/Events_InfoMessage.h
+++ b/src/Events/Events_InfoMessage.h
@@ -24,7 +24,7 @@ public:
 
   /// Constructor
   /// \param theSender a pointer on sender object
-  Events_InfoMessage(const void* theSender = 0):Events_Message(Events_Loop::eventByName("InfoMessage"), theSender) {}
+  explicit Events_InfoMessage(const void* theSender = 0):Events_Message(Events_Loop::eventByName("InfoMessage"), theSender) {}
 
   /// Constructor
   /// \param theSender a pointer on sender object
@@ -54,6 +54,15 @@ public:
   /// Returns message
   std::string messageString() const { return myMessage; }
 
+  Events_InfoMessage& operator=(const std::string& theMsg) {
+    setMessageString(theMsg);
+    return *this;
+  }
+
+  bool empty() const {
+    return myMessage.empty();
+  }
+
   /// Add parameter for message string of string type
   /// \param theParam the parameter
   void addParameter(const std::string& theParam) 
@@ -99,4 +108,4 @@ private:
   std::list<std::string> myParameters;
 };
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/ExchangePlugin/ExchangePlugin_Validators.cpp b/src/ExchangePlugin/ExchangePlugin_Validators.cpp
index e08b9854a..a0117d84e 100644
--- a/src/ExchangePlugin/ExchangePlugin_Validators.cpp
+++ b/src/ExchangePlugin/ExchangePlugin_Validators.cpp
@@ -8,6 +8,8 @@
 
 #include <ExchangePlugin_Tools.h>
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_Feature.h>
 #include <ModelAPI_Object.h>
 #include <ModelAPI_Session.h>
@@ -39,7 +41,7 @@ bool ExchangePlugin_FormatValidator::parseFormats(const std::list<std::string>&
 
 bool ExchangePlugin_FormatValidator::isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const
+                                             Events_InfoMessage& theError) const
 {
   if (!theAttribute->isInitialized()) {
     theError = "Is not initialized.";
diff --git a/src/ExchangePlugin/ExchangePlugin_Validators.h b/src/ExchangePlugin/ExchangePlugin_Validators.h
index ab1a142f9..61613f35e 100644
--- a/src/ExchangePlugin/ExchangePlugin_Validators.h
+++ b/src/ExchangePlugin/ExchangePlugin_Validators.h
@@ -35,7 +35,7 @@ public:
    */
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /**
diff --git a/src/FeaturesPlugin/FeaturesPlugin_ValidatorTransform.cpp b/src/FeaturesPlugin/FeaturesPlugin_ValidatorTransform.cpp
index 570d1fb6f..9722f8836 100755
--- a/src/FeaturesPlugin/FeaturesPlugin_ValidatorTransform.cpp
+++ b/src/FeaturesPlugin/FeaturesPlugin_ValidatorTransform.cpp
@@ -2,6 +2,8 @@
 
 #include "FeaturesPlugin_ValidatorTransform.h"
 
+#include <Events_InfoMessage.h>
+
 #include "ModelAPI_AttributeSelectionList.h"
 #include "ModelAPI_ResultPart.h"
 #include "ModelAPI_ResultBody.h"
@@ -10,7 +12,7 @@
 
 bool FeaturesPlugin_ValidatorTransform::isValid(const AttributePtr& theAttribute,
                                                 const std::list<std::string>& theArguments,
-                                                std::string& theError) const
+                                                Events_InfoMessage& theError) const
 {
   bool aValid = true;
   std::string anAttributeType = theAttribute->attributeType();
diff --git a/src/FeaturesPlugin/FeaturesPlugin_ValidatorTransform.h b/src/FeaturesPlugin/FeaturesPlugin_ValidatorTransform.h
index b957253e3..f57f2f9bd 100755
--- a/src/FeaturesPlugin/FeaturesPlugin_ValidatorTransform.h
+++ b/src/FeaturesPlugin/FeaturesPlugin_ValidatorTransform.h
@@ -23,7 +23,7 @@ class FeaturesPlugin_ValidatorTransform : public ModelAPI_AttributeValidator
    */
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 #endif
diff --git a/src/FeaturesPlugin/FeaturesPlugin_Validators.cpp b/src/FeaturesPlugin/FeaturesPlugin_Validators.cpp
index db8348cd2..58c77cdd4 100644
--- a/src/FeaturesPlugin/FeaturesPlugin_Validators.cpp
+++ b/src/FeaturesPlugin/FeaturesPlugin_Validators.cpp
@@ -8,6 +8,8 @@
 
 #include "FeaturesPlugin_Union.h"
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_Attribute.h>
 #include <ModelAPI_AttributeInteger.h>
 #include <ModelAPI_AttributeSelectionList.h>
@@ -38,7 +40,7 @@
 //==================================================================================================
 bool FeaturesPlugin_ValidatorPipePath::isValid(const AttributePtr& theAttribute,
                                                const std::list<std::string>& theArguments,
-                                               std::string& theError) const
+                                               Events_InfoMessage& theError) const
 {
   AttributeSelectionPtr aPathAttrSelection = std::dynamic_pointer_cast<ModelAPI_AttributeSelection>(theAttribute);
   if(!aPathAttrSelection.get()) {
@@ -64,7 +66,7 @@ bool FeaturesPlugin_ValidatorPipePath::isValid(const AttributePtr& theAttribute,
 //==================================================================================================
 bool FeaturesPlugin_ValidatorPipeLocations::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                                     const std::list<std::string>& theArguments,
-                                                    std::string& theError) const
+                                                    Events_InfoMessage& theError) const
 {
   static const std::string aCreationMethodID = "creation_method";
   static const std::string aBaseObjectsID = "base_objects";
@@ -114,7 +116,7 @@ bool FeaturesPlugin_ValidatorPipeLocations::isNotObligatory(std::string theFeatu
 //==================================================================================================
 bool FeaturesPlugin_ValidatorBaseForGeneration::isValid(const AttributePtr& theAttribute,
                                                         const std::list<std::string>& theArguments,
-                                                        std::string& theError) const
+                                                        Events_InfoMessage& theError) const
 {
   if(theArguments.empty()) {
     theError = "Error: Validator parameters is empty.";
@@ -207,7 +209,7 @@ bool FeaturesPlugin_ValidatorBaseForGeneration::isValid(const AttributePtr& theA
 //==================================================================================================
 bool FeaturesPlugin_ValidatorBaseForGeneration::isValidAttribute(const AttributePtr& theAttribute,
                                                                  const std::list<std::string>& theArguments,
-                                                                 std::string& theError) const
+                                                                 Events_InfoMessage& theError) const
 {
   if(!theAttribute.get()) {
     theError = "Error: Empty attribute.";
@@ -275,12 +277,14 @@ bool FeaturesPlugin_ValidatorBaseForGeneration::isValidAttribute(const Attribute
     GeomValidators_ShapeType aShapeTypeValidator;
     if(!aShapeTypeValidator.isValid(anAttr, theArguments, theError)) {
       theError = "Error: Selected shape has unacceptable type. Acceptable types are: faces or wires on sketch, "
-                 "whole sketch(if it has at least one face), and whole objects with shape types: ";
-      std::list<std::string>::const_iterator anIt = theArguments.cbegin();
-      theError += *anIt;
-      for(++anIt; anIt != theArguments.cend(); ++anIt) {
-        theError += ", " + *anIt;
+                 "whole sketch(if it has at least one face), and whole objects with shape types: %1";
+      std::string anArgumentString;
+      for(auto anIt = theArguments.cbegin(); anIt != theArguments.cend(); ++anIt) {
+        if (!anArgumentString.empty())
+          anArgumentString += ", ";
+        anArgumentString += *anIt;
       }
+      theError.arg(anArgumentString);
       return false;
     }
 
@@ -295,7 +299,7 @@ bool FeaturesPlugin_ValidatorBaseForGeneration::isValidAttribute(const Attribute
 //==================================================================================================
 bool FeaturesPlugin_ValidatorCompositeLauncher::isValid(const AttributePtr& theAttribute,
                                                         const std::list<std::string>& theArguments,
-                                                        std::string& theError) const
+                                                        Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeReference::typeId()) {
     theError = "Error: The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -340,7 +344,7 @@ bool FeaturesPlugin_ValidatorCompositeLauncher::isValid(const AttributePtr& theA
 //==================================================================================================
 bool FeaturesPlugin_ValidatorExtrusionDir::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                                  const std::list<std::string>& theArguments,
-                                                 std::string& theError) const
+                                                 Events_InfoMessage& theError) const
 {
   if(theArguments.size() != 2) {
     theError = "Error: Validator should be used with 2 parameters for extrusion.";
@@ -427,7 +431,7 @@ bool FeaturesPlugin_ValidatorExtrusionDir::isNotObligatory(std::string theFeatur
 
 //==================================================================================================
 bool FeaturesPlugin_ValidatorExtrusionDir::isShapesCanBeEmpty(const AttributePtr& theAttribute,
-                                                            std::string& theError) const
+                                                              Events_InfoMessage& theError) const
 {
   if(!theAttribute.get()) {
     return true;
@@ -474,7 +478,7 @@ bool FeaturesPlugin_ValidatorExtrusionDir::isShapesCanBeEmpty(const AttributePtr
 //==================================================================================================
 bool FeaturesPlugin_ValidatorBooleanSelection::isValid(const AttributePtr& theAttribute,
                                                        const std::list<std::string>& theArguments,
-                                                       std::string& theError) const
+                                                       Events_InfoMessage& theError) const
 {
   AttributeSelectionListPtr anAttrSelectionList = std::dynamic_pointer_cast<ModelAPI_AttributeSelectionList>(theAttribute);
   if(!anAttrSelectionList.get()) {
@@ -536,7 +540,7 @@ bool FeaturesPlugin_ValidatorBooleanSelection::isValid(const AttributePtr& theAt
 //==================================================================================================
 bool FeaturesPlugin_ValidatorPartitionSelection::isValid(const AttributePtr& theAttribute,
                                                          const std::list<std::string>& theArguments,
-                                                         std::string& theError) const
+                                                         Events_InfoMessage& theError) const
 {
   AttributeSelectionListPtr anAttrSelectionList = std::dynamic_pointer_cast<ModelAPI_AttributeSelectionList>(theAttribute);
   if(!anAttrSelectionList.get()) {
@@ -580,7 +584,7 @@ bool FeaturesPlugin_ValidatorPartitionSelection::isValid(const AttributePtr& the
 //==================================================================================================
 bool FeaturesPlugin_ValidatorRemoveSubShapesSelection::isValid(const AttributePtr& theAttribute,
                                                                const std::list<std::string>& theArguments,
-                                                               std::string& theError) const
+                                                               Events_InfoMessage& theError) const
 {
   AttributeSelectionListPtr aSubShapesAttrList = std::dynamic_pointer_cast<ModelAPI_AttributeSelectionList>(theAttribute);
   if(!aSubShapesAttrList.get()) {
@@ -633,7 +637,7 @@ bool FeaturesPlugin_ValidatorRemoveSubShapesSelection::isValid(const AttributePt
 //==================================================================================================
 bool FeaturesPlugin_ValidatorRemoveSubShapesResult::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                                             const std::list<std::string>& theArguments,
-                                                            std::string& theError) const
+                                                            Events_InfoMessage& theError) const
 {
   static const std::string aBaseShapeID = "base_shape";
   static const std::string aSubShapesID = "subshapes";
@@ -689,7 +693,7 @@ bool FeaturesPlugin_ValidatorRemoveSubShapesResult::isNotObligatory(std::string
 //==================================================================================================
 bool FeaturesPlugin_ValidatorUnionSelection::isValid(const AttributePtr& theAttribute,
                                                      const std::list<std::string>& theArguments,
-                                                     std::string& theError) const
+                                                     Events_InfoMessage& theError) const
 {
   AttributeSelectionListPtr aBaseObjectsAttrList = std::dynamic_pointer_cast<ModelAPI_AttributeSelectionList>(theAttribute);
   if(!aBaseObjectsAttrList.get()) {
@@ -716,7 +720,7 @@ bool FeaturesPlugin_ValidatorUnionSelection::isValid(const AttributePtr& theAttr
 //==================================================================================================
 bool FeaturesPlugin_ValidatorUnionArguments::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                                      const std::list<std::string>& theArguments,
-                                                     std::string& theError) const
+                                                     Events_InfoMessage& theError) const
 {
   // Check feature kind.
   if(theFeature->getKind() != FeaturesPlugin_Union::ID()) {
diff --git a/src/FeaturesPlugin/FeaturesPlugin_Validators.h b/src/FeaturesPlugin/FeaturesPlugin_Validators.h
index c806e754b..ce3fe042e 100644
--- a/src/FeaturesPlugin/FeaturesPlugin_Validators.h
+++ b/src/FeaturesPlugin/FeaturesPlugin_Validators.h
@@ -22,7 +22,7 @@ public:
   //! \param[out] theError error message.
    virtual bool isValid(const AttributePtr& theAttribute,
                         const std::list<std::string>& theArguments,
-                        std::string& theError) const;
+                        Events_InfoMessage& theError) const;
 };
 
 /// \class FeaturesPlugin_ValidatorPipeLocations
@@ -37,7 +37,7 @@ class FeaturesPlugin_ValidatorPipeLocations: public ModelAPI_FeatureValidator
   //! \param theError error message
   virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 
   /// Returns true if the attribute in feature is not obligatory for the feature execution
   virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
@@ -56,12 +56,12 @@ public:
   //! \param[out] theError error message.
    virtual bool isValid(const AttributePtr& theAttribute,
                         const std::list<std::string>& theArguments,
-                        std::string& theError) const;
+                        Events_InfoMessage& theError) const;
 
 private:
   bool isValidAttribute(const AttributePtr& theAttribute,
                         const std::list<std::string>& theArguments,
-                        std::string& theError) const;
+                        Events_InfoMessage& theError) const;
 };
 
 /// \class FeaturesPlugin_ValidatorCompositeLauncher
@@ -76,7 +76,7 @@ public:
   //! \param[out] theError error message.
    virtual bool isValid(const AttributePtr& theAttribute,
                         const std::list<std::string>& theArguments,
-                        std::string& theError) const;
+                        Events_InfoMessage& theError) const;
 };
 
 /// \class FeaturesPlugin_ValidatorExtrusionDir
@@ -92,14 +92,14 @@ public:
   //! \param[out] theError error message.
   virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 
   /// \return true if the attribute in feature is not obligatory for the feature execution
   virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
 
 private:
   bool isShapesCanBeEmpty(const AttributePtr& theAttribute,
-                          std::string& theError) const;
+                          Events_InfoMessage& theError) const;
 };
 
 /// \class FeaturesPlugin_ValidatorBooleanSelection
@@ -115,7 +115,7 @@ public:
   /// \param[out] theError error message.
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /// \class FeaturesPlugin_ValidatorPartitionSelection
@@ -131,7 +131,7 @@ public:
   /// \param[out] theError error message.
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /// \class FeaturesPlugin_ValidatorRemoveSubShapesSelection
@@ -147,7 +147,7 @@ public:
   /// \param[out] theError error message.
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /// \class FeaturesPlugin_ValidatorRemoveSubShapesResult
@@ -162,7 +162,7 @@ class FeaturesPlugin_ValidatorRemoveSubShapesResult: public ModelAPI_FeatureVali
   //! \param theError error message
   virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 
   /// \return true if the attribute in feature is not obligatory for the feature execution
   virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
@@ -181,7 +181,7 @@ public:
   /// \param[out] theError error message.
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /// \class FeaturesPlugin_ValidatorUnionArguments
@@ -196,7 +196,7 @@ class FeaturesPlugin_ValidatorUnionArguments: public ModelAPI_FeatureValidator
   //! \param theError error message
   virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 
   /// \return true if the attribute in feature is not obligatory for the feature execution
   virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
diff --git a/src/GeomValidators/GeomValidators_BodyShapes.cpp b/src/GeomValidators/GeomValidators_BodyShapes.cpp
index 18bd9918a..a681fbe5d 100644
--- a/src/GeomValidators/GeomValidators_BodyShapes.cpp
+++ b/src/GeomValidators/GeomValidators_BodyShapes.cpp
@@ -6,13 +6,15 @@
 
 #include "GeomValidators_BodyShapes.h"
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeSelectionList.h>
 #include <ModelAPI_Object.h>
 #include <ModelAPI_ResultConstruction.h>
 
 bool GeomValidators_BodyShapes::isValid(const AttributePtr& theAttribute,
                                         const std::list<std::string>& theArguments,
-                                        std::string& theError) const
+                                        Events_InfoMessage& theError) const
 {
   std::string anAttributeType = theAttribute->attributeType();
   if(anAttributeType == ModelAPI_AttributeSelection::typeId()) {
diff --git a/src/GeomValidators/GeomValidators_BodyShapes.h b/src/GeomValidators/GeomValidators_BodyShapes.h
index 33e2f8f50..5058cfcb8 100644
--- a/src/GeomValidators/GeomValidators_BodyShapes.h
+++ b/src/GeomValidators/GeomValidators_BodyShapes.h
@@ -25,7 +25,7 @@ public:
   /// \param[out] theError error message.
   GEOMVALIDATORS_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 };
 
 #endif
diff --git a/src/GeomValidators/GeomValidators_BooleanArguments.cpp b/src/GeomValidators/GeomValidators_BooleanArguments.cpp
index b54344510..1db13e607 100644
--- a/src/GeomValidators/GeomValidators_BooleanArguments.cpp
+++ b/src/GeomValidators/GeomValidators_BooleanArguments.cpp
@@ -6,13 +6,15 @@
 
 #include <GeomValidators_BooleanArguments.h>
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeInteger.h>
 #include <ModelAPI_AttributeSelectionList.h>
 
 //=================================================================================================
 bool GeomValidators_BooleanArguments::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                               const std::list<std::string>& theArguments,
-                                              std::string& theError) const
+                                              Events_InfoMessage& theError) const
 {
   if(theArguments.size() != 3) {
     theError = "Wrong number of arguments (expected 3).";
diff --git a/src/GeomValidators/GeomValidators_BooleanArguments.h b/src/GeomValidators/GeomValidators_BooleanArguments.h
index 1686c8ee4..42a46d53a 100644
--- a/src/GeomValidators/GeomValidators_BooleanArguments.h
+++ b/src/GeomValidators/GeomValidators_BooleanArguments.h
@@ -26,7 +26,7 @@ public:
    */
   GEOMVALIDATORS_EXPORT virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 
   /// \return true if the attribute in feature is not obligatory for the feature execution.
   GEOMVALIDATORS_EXPORT virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
diff --git a/src/GeomValidators/GeomValidators_ConstructionComposite.cpp b/src/GeomValidators/GeomValidators_ConstructionComposite.cpp
index b19719831..c748c2cdc 100644
--- a/src/GeomValidators/GeomValidators_ConstructionComposite.cpp
+++ b/src/GeomValidators/GeomValidators_ConstructionComposite.cpp
@@ -2,13 +2,15 @@
 
 #include "GeomValidators_ConstructionComposite.h"
 
+#include <Events_InfoMessage.h>
+
 #include "ModelAPI_AttributeSelection.h"
 #include "ModelAPI_ResultConstruction.h"
 #include "ModelAPI_CompositeFeature.h"
 
 bool GeomValidators_ConstructionComposite::isValid(const AttributePtr& theAttribute,
                                                    const std::list<std::string>& theArguments,
-                                                   std::string& theError) const
+                                                   Events_InfoMessage& theError) const
 {
   bool aValid = true;
   if (theAttribute->attributeType() != ModelAPI_AttributeSelection::typeId()) {
diff --git a/src/GeomValidators/GeomValidators_ConstructionComposite.h b/src/GeomValidators/GeomValidators_ConstructionComposite.h
index fb37f95bc..67a2a3a30 100644
--- a/src/GeomValidators/GeomValidators_ConstructionComposite.h
+++ b/src/GeomValidators/GeomValidators_ConstructionComposite.h
@@ -24,7 +24,7 @@ class GeomValidators_ConstructionComposite : public ModelAPI_AttributeValidator
   //! \param[out] theError error message.
   GEOMVALIDATORS_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 };
 
 #endif
diff --git a/src/GeomValidators/GeomValidators_Different.cpp b/src/GeomValidators/GeomValidators_Different.cpp
index 94c369c5a..617161f9c 100644
--- a/src/GeomValidators/GeomValidators_Different.cpp
+++ b/src/GeomValidators/GeomValidators_Different.cpp
@@ -6,6 +6,8 @@
 
 #include <GeomValidators_Different.h>
 
+#include <Events_InfoMessage.h>
+
 #include <GeomDataAPI_Point2D.h>
 #include <GeomAPI_Pnt2d.h>
 
@@ -54,7 +56,7 @@ public:
 
 bool GeomValidators_Different::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                        const std::list<std::string>& theArguments,
-                                       std::string& theError) const
+                                       Events_InfoMessage& theError) const
 {
   std::map<std::string, std::list<AttributePtr> > anAttributesMap;
   // For all attributes referred by theArguments 
diff --git a/src/GeomValidators/GeomValidators_Different.h b/src/GeomValidators/GeomValidators_Different.h
index a5be84f7b..e5d7e15bf 100644
--- a/src/GeomValidators/GeomValidators_Different.h
+++ b/src/GeomValidators/GeomValidators_Different.h
@@ -26,7 +26,7 @@ public:
    */
   GEOMVALIDATORS_EXPORT virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 
   GEOMVALIDATORS_EXPORT virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
 };
diff --git a/src/GeomValidators/GeomValidators_DifferentShapes.cpp b/src/GeomValidators/GeomValidators_DifferentShapes.cpp
index e9470daf4..7eefe2626 100644
--- a/src/GeomValidators/GeomValidators_DifferentShapes.cpp
+++ b/src/GeomValidators/GeomValidators_DifferentShapes.cpp
@@ -6,12 +6,14 @@
 
 #include "GeomValidators_DifferentShapes.h"
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeSelection.h>
 #include "ModelAPI_Object.h"
 
 bool GeomValidators_DifferentShapes::isValid(const AttributePtr& theAttribute,
                                       const std::list<std::string>& theArguments,
-                                      std::string& theError) const
+                                      Events_InfoMessage& theError) const
 {
   FeaturePtr aFeature = std::dynamic_pointer_cast<ModelAPI_Feature>(theAttribute->owner());
   AttributeSelectionPtr aSelectionAttribute = 
diff --git a/src/GeomValidators/GeomValidators_DifferentShapes.h b/src/GeomValidators/GeomValidators_DifferentShapes.h
index ac3dd5b58..2bfef9711 100644
--- a/src/GeomValidators/GeomValidators_DifferentShapes.h
+++ b/src/GeomValidators/GeomValidators_DifferentShapes.h
@@ -25,7 +25,7 @@ public:
   /// \param[out] theError error message.
   GEOMVALIDATORS_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 };
 
 #endif
diff --git a/src/GeomValidators/GeomValidators_Face.cpp b/src/GeomValidators/GeomValidators_Face.cpp
index f91066da2..391ae4f82 100644
--- a/src/GeomValidators/GeomValidators_Face.cpp
+++ b/src/GeomValidators/GeomValidators_Face.cpp
@@ -34,7 +34,7 @@ GeomAbs_SurfaceType faceType(const std::string& theType)
 
 bool GeomValidators_Face::isValid(const AttributePtr& theAttribute,
                                   const std::list<std::string>& theArguments,
-                                  std::string& theError) const
+                                  Events_InfoMessage& theError) const
 {
   std::string anAttributeType = theAttribute->attributeType();
   if (anAttributeType != ModelAPI_AttributeSelection::typeId()) {
diff --git a/src/GeomValidators/GeomValidators_Face.h b/src/GeomValidators/GeomValidators_Face.h
index f547dbb47..c3b802658 100644
--- a/src/GeomValidators/GeomValidators_Face.h
+++ b/src/GeomValidators/GeomValidators_Face.h
@@ -24,7 +24,7 @@ class GeomValidators_Face : public ModelAPI_AttributeValidator
   //! \param[out] theError error message.
   GEOMVALIDATORS_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 };
 
 #endif
diff --git a/src/GeomValidators/GeomValidators_FeatureKind.cpp b/src/GeomValidators/GeomValidators_FeatureKind.cpp
index 9c663a1f7..c6036e414 100755
--- a/src/GeomValidators/GeomValidators_FeatureKind.cpp
+++ b/src/GeomValidators/GeomValidators_FeatureKind.cpp
@@ -6,6 +6,8 @@
 
 #include "GeomValidators_FeatureKind.h"
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeSelectionList.h>
 #include <ModelAPI_AttributeRefList.h>
 #include <ModelAPI_AttributeRefAttr.h>
@@ -19,7 +21,7 @@
 
 bool GeomValidators_FeatureKind::isValid(const AttributePtr& theAttribute,
                                       const std::list<std::string>& theArguments,
-                                      std::string& theError) const
+                                      Events_InfoMessage& theError) const
 {
   bool isSketchEntities = true;
   std::set<std::string> anEntityKinds;
diff --git a/src/GeomValidators/GeomValidators_FeatureKind.h b/src/GeomValidators/GeomValidators_FeatureKind.h
index 894992753..4884aed1d 100755
--- a/src/GeomValidators/GeomValidators_FeatureKind.h
+++ b/src/GeomValidators/GeomValidators_FeatureKind.h
@@ -25,7 +25,7 @@ public:
   /// \param[out] theError error message.
   GEOMVALIDATORS_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 };
 
 #endif
diff --git a/src/GeomValidators/GeomValidators_Finite.cpp b/src/GeomValidators/GeomValidators_Finite.cpp
index 150415cb1..6668b8bba 100755
--- a/src/GeomValidators/GeomValidators_Finite.cpp
+++ b/src/GeomValidators/GeomValidators_Finite.cpp
@@ -6,12 +6,14 @@
 
 #include <GeomValidators_Finite.h>
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeSelectionList.h>
 #include <ModelAPI_ResultConstruction.h>
 
 bool GeomValidators_Finite::isValid(const AttributePtr& theAttribute,
                                    const std::list<std::string>& theArguments,
-                                   std::string& theError) const
+                                   Events_InfoMessage& theError) const
 {
   bool aValid = true;
 
diff --git a/src/GeomValidators/GeomValidators_Finite.h b/src/GeomValidators/GeomValidators_Finite.h
index 85b5b9803..78c6b7c45 100755
--- a/src/GeomValidators/GeomValidators_Finite.h
+++ b/src/GeomValidators/GeomValidators_Finite.h
@@ -23,7 +23,7 @@ public:
   //! \param[out] theError error message.
   GEOMVALIDATORS_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 };
 
 #endif
diff --git a/src/GeomValidators/GeomValidators_IntersectionSelection.cpp b/src/GeomValidators/GeomValidators_IntersectionSelection.cpp
index e3899d7f5..ec2a886e0 100644
--- a/src/GeomValidators/GeomValidators_IntersectionSelection.cpp
+++ b/src/GeomValidators/GeomValidators_IntersectionSelection.cpp
@@ -6,13 +6,15 @@
 
 #include "GeomValidators_IntersectionSelection.h"
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeInteger.h>
 #include <ModelAPI_AttributeSelectionList.h>
 #include <ModelAPI_Feature.h>
 
 bool GeomValidators_IntersectionSelection::isValid(const AttributePtr& theAttribute,
                                                    const std::list<std::string>& theArguments,
-                                                   std::string& theError) const
+                                                   Events_InfoMessage& theError) const
 {
   if(!theAttribute.get()) {
     theError = "Error: empty selection.";
@@ -40,9 +42,8 @@ bool GeomValidators_IntersectionSelection::isValid(const AttributePtr& theAttrib
     if(aFeatureKind == "Sketch" ||
        aFeatureKind == "Plane" ||
        aFeatureKind == "Axis") {
-      theError = "Error: ";
-      theError += aFeatureKind;
-      theError += " shape is not allowed for selection.";
+      theError = "Error: %1 shape is not allowed for selection.";
+      theError.arg(aFeatureKind);
       return false;
     }
     std::shared_ptr<GeomAPI_Shape> aShape = anAttrSelection->value();
diff --git a/src/GeomValidators/GeomValidators_IntersectionSelection.h b/src/GeomValidators/GeomValidators_IntersectionSelection.h
index 35a78c04b..b3de2da03 100644
--- a/src/GeomValidators/GeomValidators_IntersectionSelection.h
+++ b/src/GeomValidators/GeomValidators_IntersectionSelection.h
@@ -25,7 +25,7 @@ public:
   /// \param[out] theError error message.
   GEOMVALIDATORS_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 };
 
 #endif
diff --git a/src/GeomValidators/GeomValidators_MinObjectsSelected.cpp b/src/GeomValidators/GeomValidators_MinObjectsSelected.cpp
index 58e39b3a0..aa4088daa 100644
--- a/src/GeomValidators/GeomValidators_MinObjectsSelected.cpp
+++ b/src/GeomValidators/GeomValidators_MinObjectsSelected.cpp
@@ -6,13 +6,15 @@
 
 #include <GeomValidators_MinObjectsSelected.h>
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeInteger.h>
 #include <ModelAPI_AttributeSelectionList.h>
 
 //=================================================================================================
 bool GeomValidators_MinObjectsSelected::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                                 const std::list<std::string>& theArguments,
-                                                std::string& theError) const
+                                                Events_InfoMessage& theError) const
 {
   if(theArguments.size() != 2) {
     theError = "Error: Wrong number of arguments (expected 2): selection list id and min number of objects";
diff --git a/src/GeomValidators/GeomValidators_MinObjectsSelected.h b/src/GeomValidators/GeomValidators_MinObjectsSelected.h
index cdcb20a27..27f860c81 100644
--- a/src/GeomValidators/GeomValidators_MinObjectsSelected.h
+++ b/src/GeomValidators/GeomValidators_MinObjectsSelected.h
@@ -24,7 +24,7 @@ public:
   /// \returns true if feature is valid.
   GEOMVALIDATORS_EXPORT virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 
   /// \return true if the attribute in feature is not obligatory for the feature execution.
   GEOMVALIDATORS_EXPORT virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
diff --git a/src/GeomValidators/GeomValidators_PartitionArguments.cpp b/src/GeomValidators/GeomValidators_PartitionArguments.cpp
index e94ebca48..9d017b017 100644
--- a/src/GeomValidators/GeomValidators_PartitionArguments.cpp
+++ b/src/GeomValidators/GeomValidators_PartitionArguments.cpp
@@ -6,13 +6,15 @@
 
 #include <GeomValidators_PartitionArguments.h>
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeBoolean.h>
 #include <ModelAPI_AttributeSelectionList.h>
 
 //=================================================================================================
 bool GeomValidators_PartitionArguments::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                               const std::list<std::string>& theArguments,
-                                              std::string& theError) const
+                                              Events_InfoMessage& theError) const
 {
   if(theArguments.size() != 3) {
     theError = "Wrong number of arguments (expected 3).";
diff --git a/src/GeomValidators/GeomValidators_PartitionArguments.h b/src/GeomValidators/GeomValidators_PartitionArguments.h
index 1b3207001..6d7c3a833 100644
--- a/src/GeomValidators/GeomValidators_PartitionArguments.h
+++ b/src/GeomValidators/GeomValidators_PartitionArguments.h
@@ -26,7 +26,7 @@ public:
    */
   GEOMVALIDATORS_EXPORT virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 
   /// \return true if the attribute in feature is not obligatory for the feature execution.
   GEOMVALIDATORS_EXPORT virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
diff --git a/src/GeomValidators/GeomValidators_Positive.cpp b/src/GeomValidators/GeomValidators_Positive.cpp
index b127ffe03..17c38fb19 100644
--- a/src/GeomValidators/GeomValidators_Positive.cpp
+++ b/src/GeomValidators/GeomValidators_Positive.cpp
@@ -5,6 +5,9 @@
 // Author:      Mikhail PONIKAROV
 
 #include "GeomValidators_Positive.h"
+
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeDouble.h>
 #include <ModelAPI_AttributeInteger.h>
 #include <ModelAPI_Session.h>
@@ -25,7 +28,7 @@ GeomValidators_Positive::GeomValidators_Positive()
 
 bool GeomValidators_Positive::isValid(const AttributePtr& theAttribute, 
                                       const std::list<std::string>& theArguments,
-                                      std::string& theError) const
+                                      Events_InfoMessage& theError) const
 {
   double aMinValue = 1.e-5;
   if(theArguments.size() == 1) {
diff --git a/src/GeomValidators/GeomValidators_Positive.h b/src/GeomValidators/GeomValidators_Positive.h
index 0e15c77d2..08a30d288 100644
--- a/src/GeomValidators/GeomValidators_Positive.h
+++ b/src/GeomValidators/GeomValidators_Positive.h
@@ -24,7 +24,7 @@ public:
   //! \param[out] theError error message.
   GEOMVALIDATORS_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 
 };
 
diff --git a/src/GeomValidators/GeomValidators_ShapeType.cpp b/src/GeomValidators/GeomValidators_ShapeType.cpp
index 8bc0d9fbd..2027c50ea 100755
--- a/src/GeomValidators/GeomValidators_ShapeType.cpp
+++ b/src/GeomValidators/GeomValidators_ShapeType.cpp
@@ -64,7 +64,7 @@ std::string getShapeTypeDescription(const GeomValidators_ShapeType::TypeOfShape&
 
 bool GeomValidators_ShapeType::isValid(const AttributePtr& theAttribute,
                                        const std::list<std::string>& theArguments,
-                                       std::string& theError) const
+                                       Events_InfoMessage& theError) const
 {
   bool aValid = false;
 
@@ -99,7 +99,7 @@ bool GeomValidators_ShapeType::isValid(const AttributePtr& theAttribute,
 
 bool GeomValidators_ShapeType::isValidAttribute(const AttributePtr& theAttribute,
                                                 const TypeOfShape theShapeType,
-                                                std::string& theError) const
+                                                Events_InfoMessage& theError) const
 {
   bool aValid = true;
 
@@ -160,7 +160,7 @@ bool GeomValidators_ShapeType::isValidAttribute(const AttributePtr& theAttribute
 
 bool GeomValidators_ShapeType::isValidObject(const ObjectPtr& theObject,
                                              const TypeOfShape theShapeType,
-                                             std::string& theError) const
+                                             Events_InfoMessage& theError) const
 {
   bool aValid = true;
   if (!theObject.get()) {
@@ -191,7 +191,7 @@ bool GeomValidators_ShapeType::isValidObject(const ObjectPtr& theObject,
 
 bool GeomValidators_ShapeType::isValidShape(const GeomShapePtr theShape,
                                             const TypeOfShape theShapeType,
-                                            std::string& theError) const
+                                            Events_InfoMessage& theError) const
 {
   bool aValid = true;
 
diff --git a/src/GeomValidators/GeomValidators_ShapeType.h b/src/GeomValidators/GeomValidators_ShapeType.h
index 3d2c60e65..0146cfda7 100644
--- a/src/GeomValidators/GeomValidators_ShapeType.h
+++ b/src/GeomValidators/GeomValidators_ShapeType.h
@@ -49,7 +49,7 @@ class GeomValidators_ShapeType : public ModelAPI_AttributeValidator
   //! \param[out] theError error message.
   GEOMVALIDATORS_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 protected:
   /// Convert string to TypeOfShape value
   /// \param theType a string value
@@ -61,7 +61,7 @@ protected:
   /// \param[out] theError error message.
   bool isValidAttribute(const AttributePtr& theAttribute,
                         const TypeOfShape theShapeType,
-                        std::string& theError) const;
+                        Events_InfoMessage& theError) const;
 
   /// Returns true if the attibute's object type satisfies the argument value
   /// \param[in] theObject a checked object
@@ -69,7 +69,7 @@ protected:
   /// \param[out] theError error message.
   bool isValidObject(const ObjectPtr& theObject,
                      const TypeOfShape theShapeType,
-                     std::string& theError) const;
+                     Events_InfoMessage& theError) const;
 
   /// Returns true if the attibute's object type satisfies the argument value
   /// \param[in] theShape a checked shape
@@ -77,7 +77,7 @@ protected:
   /// \param[out] theError error message.
   bool isValidShape(const GeomShapePtr theShape,
                     const TypeOfShape theShapeType,
-                    std::string& theError) const;
+                    Events_InfoMessage& theError) const;
 
 };
 
diff --git a/src/GeomValidators/GeomValidators_ZeroOffset.cpp b/src/GeomValidators/GeomValidators_ZeroOffset.cpp
index f898a2297..20d324edd 100644
--- a/src/GeomValidators/GeomValidators_ZeroOffset.cpp
+++ b/src/GeomValidators/GeomValidators_ZeroOffset.cpp
@@ -6,6 +6,8 @@
 
 #include <GeomValidators_ZeroOffset.h>
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeDouble.h>
 #include <ModelAPI_AttributeSelection.h>
 #include <ModelAPI_AttributeSelectionList.h>
@@ -21,7 +23,7 @@
 //=================================================================================================
 bool GeomValidators_ZeroOffset::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                         const std::list<std::string>& theArguments,
-                                        std::string& theError) const
+                                        Events_InfoMessage& theError) const
 {
   if(theArguments.size() != 9) {
     theError = "Wrong number of validator arguments in xml(expected 9).";
diff --git a/src/GeomValidators/GeomValidators_ZeroOffset.h b/src/GeomValidators/GeomValidators_ZeroOffset.h
index 64fd4ab63..3d5c3b864 100644
--- a/src/GeomValidators/GeomValidators_ZeroOffset.h
+++ b/src/GeomValidators/GeomValidators_ZeroOffset.h
@@ -26,7 +26,7 @@ public:
    */
   GEOMVALIDATORS_EXPORT virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const;
+                                             Events_InfoMessage& theError) const;
 
   /// \return true if the attribute in feature is not obligatory for the feature execution.
   GEOMVALIDATORS_EXPORT virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
diff --git a/src/Model/Model_AttributeValidator.cpp b/src/Model/Model_AttributeValidator.cpp
index 93e321832..8cf601921 100644
--- a/src/Model/Model_AttributeValidator.cpp
+++ b/src/Model/Model_AttributeValidator.cpp
@@ -6,6 +6,8 @@
 
 #include "Model_AttributeValidator.h"
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeDouble.h>
 #include <ModelAPI_AttributeInteger.h>
 
@@ -14,7 +16,7 @@
 
 bool Model_AttributeValidator::isValid(const AttributePtr& theAttribute, 
                                        const std::list<std::string>& theArguments, 
-                                       std::string& theError) const
+                                       Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() == ModelAPI_AttributeInteger::typeId()) {
     AttributeIntegerPtr anAttribue =
diff --git a/src/Model/Model_AttributeValidator.h b/src/Model/Model_AttributeValidator.h
index 3e8240cdf..0379fbe4e 100644
--- a/src/Model/Model_AttributeValidator.h
+++ b/src/Model/Model_AttributeValidator.h
@@ -26,7 +26,7 @@ public:
   /// \returns true if attribute is valid
   MODEL_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                     const std::list<std::string>& theArguments,
-                                    std::string& theError) const;
+                                    Events_InfoMessage& theError) const;
 };
 
 #endif // Model_AttributeValidator_H
diff --git a/src/Model/Model_FeatureValidator.cpp b/src/Model/Model_FeatureValidator.cpp
index 303a46567..06923d324 100644
--- a/src/Model/Model_FeatureValidator.cpp
+++ b/src/Model/Model_FeatureValidator.cpp
@@ -5,6 +5,9 @@
 // Author:      Vitaly SMETANNIKOV
 
 #include <Model_FeatureValidator.h>
+
+#include <Events_InfoMessage.h>
+
 #include <Model_Validator.h>
 #include <ModelAPI_Attribute.h>
 #include <ModelAPI_Data.h>
@@ -17,7 +20,7 @@
 
 bool Model_FeatureValidator::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                      const std::list<std::string>& theArguments,
-                                     std::string& theError) const
+                                     Events_InfoMessage& theError) const
 {
   static Model_ValidatorsFactory* aValidators = 
     static_cast<Model_ValidatorsFactory*>(ModelAPI_Session::get()->validators());
diff --git a/src/Model/Model_FeatureValidator.h b/src/Model/Model_FeatureValidator.h
index 010ad505c..47c091937 100644
--- a/src/Model/Model_FeatureValidator.h
+++ b/src/Model/Model_FeatureValidator.h
@@ -35,7 +35,7 @@ public:
   /// \returns true if feature is valid
   MODEL_EXPORT virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                     const std::list<std::string>& theArguments,
-                                    std::string& theError) const;
+                                    Events_InfoMessage& theError) const;
 
   /// sets not obligatory attributes, not checked for initialization
   virtual void registerNotObligatory(std::string theFeature, std::string theAttribute);
diff --git a/src/Model/Model_Validator.cpp b/src/Model/Model_Validator.cpp
index dafa19583..1d420229f 100644
--- a/src/Model/Model_Validator.cpp
+++ b/src/Model/Model_Validator.cpp
@@ -177,12 +177,12 @@ bool Model_ValidatorsFactory::validate(const std::shared_ptr<ModelAPI_Feature>&
       const ModelAPI_FeatureValidator* aFValidator = 
         dynamic_cast<const ModelAPI_FeatureValidator*>(validator(aValidatorID));
       if (aFValidator) {
-        std::string anError;
+        Events_InfoMessage anError;
         if (!aFValidator->isValid(theFeature, anArguments, anError)) {
           if (anError.empty())
             anError = "Unknown error.";
-          anError = aValidatorID + ": " + anError;
-          theFeature->setError(anError, false);
+          anError = aValidatorID + ": " + anError.messageString();
+          theFeature->setError(anError.messageString(), false);
           theFeature->data()->execState(ModelAPI_StateInvalidArgument);
           return false;
         }
@@ -221,12 +221,12 @@ bool Model_ValidatorsFactory::validate(const std::shared_ptr<ModelAPI_Feature>&
     AttributePtr anAttribute = theFeature->data()->attribute(anAttributeID);
 
     std::string aValidatorID;
-    std::string anError;
+    Events_InfoMessage anError;
     if (!validate(anAttribute, aValidatorID, anError)) {
       if (anError.empty())
         anError = "Unknown error.";
-      anError = anAttributeID + " - " + aValidatorID + ": " + anError;
-      theFeature->setError(anError, false);
+      anError = anAttributeID + " - " + aValidatorID + ": " + anError.messageString();
+      theFeature->setError(anError.messageString(), false);
       theFeature->data()->execState(ModelAPI_StateInvalidArgument);
       return false;
     } 
@@ -237,7 +237,7 @@ bool Model_ValidatorsFactory::validate(const std::shared_ptr<ModelAPI_Feature>&
 
 bool Model_ValidatorsFactory::validate(const std::shared_ptr<ModelAPI_Attribute>& theAttribute,
                                        std::string& theValidator,
-                                       std::string& theError) const
+                                       Events_InfoMessage& theError) const
 {
   FeaturePtr aFeature = ModelAPI_Feature::feature(theAttribute->owner());
   if (!aFeature.get()) {
diff --git a/src/Model/Model_Validator.h b/src/Model/Model_Validator.h
index 0040d8c2b..2fd016478 100644
--- a/src/Model/Model_Validator.h
+++ b/src/Model/Model_Validator.h
@@ -78,7 +78,7 @@ class Model_ValidatorsFactory : public ModelAPI_ValidatorsFactory
 
   /// Returns true if the attribute is valid.
   MODEL_EXPORT virtual bool validate(const std::shared_ptr<ModelAPI_Attribute>& theAttribute,
-                                     std::string& theValidator, std::string& theError) const;
+                                     std::string& theValidator, Events_InfoMessage& theError) const;
 
   /// register that this attribute in feature is not obligatory for the feature execution
   /// so, it is not needed for the standard validation mechanism
diff --git a/src/ModelAPI/ModelAPI_AttributeValidator.h b/src/ModelAPI/ModelAPI_AttributeValidator.h
index 142c91c23..54e5679ec 100644
--- a/src/ModelAPI/ModelAPI_AttributeValidator.h
+++ b/src/ModelAPI/ModelAPI_AttributeValidator.h
@@ -23,7 +23,7 @@ public:
   //! \param theError the error string message if validation fails
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const = 0;
+                       Events_InfoMessage& theError) const = 0;
 
   MODELAPI_EXPORT ~ModelAPI_AttributeValidator();
 };
diff --git a/src/ModelAPI/ModelAPI_FeatureValidator.h b/src/ModelAPI/ModelAPI_FeatureValidator.h
index f051c1e0d..3b995c6c1 100644
--- a/src/ModelAPI/ModelAPI_FeatureValidator.h
+++ b/src/ModelAPI/ModelAPI_FeatureValidator.h
@@ -32,7 +32,7 @@ class MODELAPI_EXPORT ModelAPI_FeatureValidator : public ModelAPI_Validator
   /// \param theError the error string message if validation fails
   virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const = 0;
+                       Events_InfoMessage& theError) const = 0;
 
   /// Returns true if the attribute in feature is not obligatory for the feature execution
   virtual bool isNotObligatory(std::string theFeature, std::string theAttribute) = 0;
diff --git a/src/ModelAPI/ModelAPI_Validator.h b/src/ModelAPI/ModelAPI_Validator.h
index af9eb2839..7fddb71ac 100644
--- a/src/ModelAPI/ModelAPI_Validator.h
+++ b/src/ModelAPI/ModelAPI_Validator.h
@@ -13,6 +13,7 @@
 #include <list>
 
 class ModelAPI_Feature;
+class Events_InfoMessage;
 
 /**\class ModelAPI_Validator
  * \ingroup DataModel
@@ -84,7 +85,7 @@ class MODELAPI_EXPORT ModelAPI_ValidatorsFactory
 
   /// Returns true if the attribute is valid.
   virtual bool validate(const std::shared_ptr<ModelAPI_Attribute>& theAttribute,
-                        std::string& theValidator, std::string& theError) const = 0;
+                        std::string& theValidator, Events_InfoMessage& theError) const = 0;
 
   /// register that this attribute in feature is not obligatory for the feature execution
   /// so, it is not needed for the standard validation mechanism
diff --git a/src/ModuleBase/ModuleBase_ModelWidget.cpp b/src/ModuleBase/ModuleBase_ModelWidget.cpp
index ba4948376..69cd60c46 100644
--- a/src/ModuleBase/ModuleBase_ModelWidget.cpp
+++ b/src/ModuleBase/ModuleBase_ModelWidget.cpp
@@ -9,6 +9,8 @@
 #include "ModuleBase_Tools.h"
 #include "ModuleBase_WidgetValidator.h"
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_Data.h>
 #include <ModelAPI_Attribute.h>
 #include <ModelAPI_Events.h>
@@ -121,16 +123,21 @@ QString ModuleBase_ModelWidget::getError(const bool theValueStateChecked) const
     return anError;
 
   std::string aValidatorID;
-  std::string anErrorMsg;
+  Events_InfoMessage anErrorMsg;
 
   static ModelAPI_ValidatorsFactory* aValidators = ModelAPI_Session::get()->validators();
   if (!aValidators->validate(anAttribute, aValidatorID, anErrorMsg)) {
     if (anErrorMsg.empty())
       anErrorMsg = "unknown error.";
-    anErrorMsg = anAttributeID + " - " + aValidatorID + ": " + anErrorMsg;
+    anErrorMsg = anAttributeID + " - " + aValidatorID + ": " + anErrorMsg.messageString();
+  }
+
+  if (!anErrorMsg.empty()) {
+    std::string aStr = Config_Translator::translate(anErrorMsg);
+    std::string aCodec = Config_Translator::codec(anErrorMsg.context());
+    anError = QTextCodec::codecForName(aCodec.c_str())->toUnicode(aStr.c_str());
   }
 
-  anError = QString::fromStdString(anErrorMsg);
   if (anError.isEmpty() && theValueStateChecked)
     anError = getValueStateError();
 
diff --git a/src/ModuleBase/ModuleBase_WidgetValidated.cpp b/src/ModuleBase/ModuleBase_WidgetValidated.cpp
index fd5e7e96a..daecef19f 100644
--- a/src/ModuleBase/ModuleBase_WidgetValidated.cpp
+++ b/src/ModuleBase/ModuleBase_WidgetValidated.cpp
@@ -7,6 +7,8 @@
 #include <ModuleBase_WidgetSelectorStore.h>
 #include <ModuleBase_ViewerPrs.h>
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_Session.h>
 #include <ModelAPI_Validator.h>
 #include <ModelAPI_AttributeValidator.h>
@@ -190,7 +192,8 @@ bool ModuleBase_WidgetValidated::isValidAttribute(const AttributePtr& theAttribu
 {
   SessionPtr aMgr = ModelAPI_Session::get();
   ModelAPI_ValidatorsFactory* aFactory = aMgr->validators();
-  std::string aValidatorID, anError;
+  std::string aValidatorID;
+  Events_InfoMessage anError;
   return aFactory->validate(theAttribute, aValidatorID, anError);
 }
 
diff --git a/src/ParametersPlugin/ParametersPlugin_EvalListener.cpp b/src/ParametersPlugin/ParametersPlugin_EvalListener.cpp
index c2deeff2d..d63741c9f 100644
--- a/src/ParametersPlugin/ParametersPlugin_EvalListener.cpp
+++ b/src/ParametersPlugin/ParametersPlugin_EvalListener.cpp
@@ -338,7 +338,8 @@ void ParametersPlugin_EvalListener::renameInDependents(std::shared_ptr<ModelAPI_
 
 bool isValidAttribute(const AttributePtr& theAttribute)
 {
-  std::string aValidator, anError;
+  std::string aValidator;
+  Events_InfoMessage anError;
   return ModelAPI_Session::get()->validators()->validate(theAttribute, aValidator, anError);
 }
 
diff --git a/src/ParametersPlugin/ParametersPlugin_Validators.cpp b/src/ParametersPlugin/ParametersPlugin_Validators.cpp
index d751c36ba..ec550aeca 100644
--- a/src/ParametersPlugin/ParametersPlugin_Validators.cpp
+++ b/src/ParametersPlugin/ParametersPlugin_Validators.cpp
@@ -9,6 +9,8 @@
 
 #include <ParametersPlugin_Parameter.h>
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeString.h>
 #include <ModelAPI_Feature.h>
 #include <ModelAPI_ResultParameter.h>
@@ -24,7 +26,7 @@ ParametersPlugin_VariableValidator::~ParametersPlugin_VariableValidator()
 
 bool ParametersPlugin_VariableValidator::isValid(const AttributePtr& theAttribute,
                                                  const std::list<std::string>& theArguments,
-                                                 std::string& theError) const
+                                                 Events_InfoMessage& theError) const
 {
   AttributeStringPtr aStrAttr = std::dynamic_pointer_cast<ModelAPI_AttributeString>(theAttribute);
   if (!aStrAttr->isInitialized()) {
@@ -95,7 +97,7 @@ ParametersPlugin_ExpressionValidator::~ParametersPlugin_ExpressionValidator()
 
 bool ParametersPlugin_ExpressionValidator::isValid(const AttributePtr& theAttribute,
                                                    const std::list<std::string>& theArguments,
-                                                   std::string& theError) const
+                                                   Events_InfoMessage& theError) const
 {
   FeaturePtr aFeature = std::dynamic_pointer_cast<ModelAPI_Feature>(theAttribute->owner());
   ResultParameterPtr aParam =
diff --git a/src/ParametersPlugin/ParametersPlugin_Validators.h b/src/ParametersPlugin/ParametersPlugin_Validators.h
index cc1812abc..421c681b3 100644
--- a/src/ParametersPlugin/ParametersPlugin_Validators.h
+++ b/src/ParametersPlugin/ParametersPlugin_Validators.h
@@ -34,7 +34,7 @@ class ParametersPlugin_VariableValidator : public ModelAPI_AttributeValidator
    */
   PARAMETERSPLUGIN_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                                const std::list<std::string>& theArguments,
-                                               std::string& theError) const;
+                                               Events_InfoMessage& theError) const;
 
  protected:
   /// Returns true if theString is a valid variable name.
@@ -63,7 +63,7 @@ class ParametersPlugin_ExpressionValidator: public ModelAPI_AttributeValidator
    */
   PARAMETERSPLUGIN_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                                const std::list<std::string>& theArguments,
-                                               std::string& theError) const;
+                                               Events_InfoMessage& theError) const;
 };
 
 
diff --git a/src/ParametersPlugin/ParametersPlugin_WidgetParamsMgr.cpp b/src/ParametersPlugin/ParametersPlugin_WidgetParamsMgr.cpp
index 35df874aa..7ab7fbf73 100644
--- a/src/ParametersPlugin/ParametersPlugin_WidgetParamsMgr.cpp
+++ b/src/ParametersPlugin/ParametersPlugin_WidgetParamsMgr.cpp
@@ -8,6 +8,8 @@
 #include "ParametersPlugin_Parameter.h"
 #include "ParametersPlugin_Validators.h"
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_ResultParameter.h>
 #include <ModelAPI_AttributeString.h>
 #include <ModelAPI_AttributeRefList.h>
@@ -252,11 +254,12 @@ bool ParametersPlugin_WidgetParamsMgr::storeValueCustom()
   ParametersPlugin_ExpressionValidator aValidator;
   std::list<std::string> aArgs;
   std::string aAttrId = ParametersPlugin_Parameter::VARIABLE_ID();
-  std::string aErr;
+  Events_InfoMessage aErr;
   int aId = 0;
   foreach(FeaturePtr aFeature, myParametersList) {
     if (!aValidator.isValid(aFeature->attribute(aAttrId), aArgs, aErr)) {
-      QMessageBox::warning(this, tr("Warning"), aErr.c_str());
+      // TODO(spo): translate
+      QMessageBox::warning(this, tr("Warning"), aErr.messageString().c_str());
       selectItemScroll(myParameters->child(aId));
       return false;
     }
diff --git a/src/PartSet/PartSet_Validators.cpp b/src/PartSet/PartSet_Validators.cpp
index 9766c0a9e..26ae2e277 100755
--- a/src/PartSet/PartSet_Validators.cpp
+++ b/src/PartSet/PartSet_Validators.cpp
@@ -19,6 +19,8 @@
 #include <ModuleBase_OperationFeature.h>
 #include <ModuleBase_ViewerPrs.h>
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_AttributeRefAttr.h>
 #include <ModelAPI_AttributeSelection.h>
 #include <ModelAPI_AttributeReference.h>
@@ -354,7 +356,7 @@ std::string PartSet_DifferentObjectsValidator::errorMessage(
 
 bool PartSet_DifferentObjectsValidator::isValid(const AttributePtr& theAttribute, 
                                                 const std::list<std::string>& theArguments,
-                                                std::string& theError) const
+                                                Events_InfoMessage& theError) const
 {
   FeaturePtr aFeature = std::dynamic_pointer_cast<ModelAPI_Feature>(theAttribute->owner());
 
@@ -524,7 +526,7 @@ bool PartSet_DifferentObjectsValidator::isValid(const AttributePtr& theAttribute
 
 bool PartSet_CoincidentAttr::isValid(const AttributePtr& theAttribute, 
                                      const std::list<std::string>& theArguments,
-                                     std::string& theError) const
+                                     Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeRefAttr::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
diff --git a/src/PartSet/PartSet_Validators.h b/src/PartSet/PartSet_Validators.h
index 2111ef63d..0b25943aa 100644
--- a/src/PartSet/PartSet_Validators.h
+++ b/src/PartSet/PartSet_Validators.h
@@ -154,7 +154,7 @@ class PartSet_DifferentObjectsValidator : public ModelAPI_AttributeValidator
   //! \param theError an output error string
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 private:
   //! Returns error message for the error type
   //! \param theType a type of error
@@ -179,7 +179,7 @@ class PartSet_CoincidentAttr : public ModelAPI_AttributeValidator
   //! \param theError an output error string
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 
diff --git a/src/PartSet/PartSet_WidgetSketchCreator.cpp b/src/PartSet/PartSet_WidgetSketchCreator.cpp
index 8daeb546d..c4035cc22 100644
--- a/src/PartSet/PartSet_WidgetSketchCreator.cpp
+++ b/src/PartSet/PartSet_WidgetSketchCreator.cpp
@@ -22,6 +22,8 @@
 
 #include <GeomAPI_Face.h>
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_Session.h>
 #include <ModelAPI_ResultBody.h>
 #include <ModelAPI_AttributeSelection.h>
@@ -461,7 +463,8 @@ void PartSet_WidgetSketchCreator::onResumed(ModuleBase_Operation* theOp)
         SessionPtr aMgr = ModelAPI_Session::get();
         ModelAPI_ValidatorsFactory* aFactory = aMgr->validators();
         AttributePtr anAttribute = myFeature->attribute(anObjectsAttribute);
-        std::string aValidatorID, anError;
+        std::string aValidatorID;
+        Events_InfoMessage anError;
         aSelList->append(aRes, GeomShapePtr());
         if (aFactory->validate(anAttribute, aValidatorID, anError))
           updateObject(aCompFeature);
@@ -479,12 +482,14 @@ bool PartSet_WidgetSketchCreator::validateSelectionList() const
 
   SessionPtr aMgr = ModelAPI_Session::get();
   ModelAPI_ValidatorsFactory* aFactory = aMgr->validators();
-  std::string aValidatorID, anError;
+  std::string aValidatorID;
+  Events_InfoMessage anError;
   bool isValidPComposite = aFactory->validate(anAttrList, aValidatorID, anError);
   if (!isValidPComposite) {
     XGUI_Workshop* aWorkshop = XGUI_Tools::workshop(myModule->workshop());
+    // TODO(spo): translate
     QMessageBox::question(aWorkshop->desktop(), tr("Apply current feature"),
-                  tr("Sketch is invalid and will be deleted.\nError: %1").arg(anError.c_str()),
+                  tr("Sketch is invalid and will be deleted.\nError: %1").arg(anError.messageString().c_str()),
                   QMessageBox::Ok);
   }
   return isValidPComposite;
diff --git a/src/SketchPlugin/SketchPlugin_ExternalValidator.cpp b/src/SketchPlugin/SketchPlugin_ExternalValidator.cpp
index 362dd94f1..9c9fc3345 100644
--- a/src/SketchPlugin/SketchPlugin_ExternalValidator.cpp
+++ b/src/SketchPlugin/SketchPlugin_ExternalValidator.cpp
@@ -7,6 +7,8 @@
 #include "SketchPlugin_ExternalValidator.h"
 #include "SketchPlugin_Feature.h"
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_Session.h>
 #include <ModelAPI_Result.h>
 #include <ModelAPI_Tools.h>
@@ -14,7 +16,7 @@
 
 bool SketchPlugin_ExternalValidator::isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const
+                                             Events_InfoMessage& theError) const
 {
   if (theArguments.size() != 1)
     return true;
diff --git a/src/SketchPlugin/SketchPlugin_ExternalValidator.h b/src/SketchPlugin/SketchPlugin_ExternalValidator.h
index 821b27de7..303e62650 100644
--- a/src/SketchPlugin/SketchPlugin_ExternalValidator.h
+++ b/src/SketchPlugin/SketchPlugin_ExternalValidator.h
@@ -26,7 +26,7 @@ public:
   /// \param theError error message
   SKETCHPLUGIN_EXPORT virtual bool isValid(const AttributePtr& theAttribute,
                                            const std::list<std::string>& theArguments,
-                                           std::string& theError) const;
+                                           Events_InfoMessage& theError) const;
 
 protected:
   /// returns true if the feature of the attribute is external
diff --git a/src/SketchPlugin/SketchPlugin_Validators.cpp b/src/SketchPlugin/SketchPlugin_Validators.cpp
index c2f1badd6..93152b1cb 100755
--- a/src/SketchPlugin/SketchPlugin_Validators.cpp
+++ b/src/SketchPlugin/SketchPlugin_Validators.cpp
@@ -20,6 +20,8 @@
 
 #include "SketcherPrs_Tools.h"
 
+#include <Events_InfoMessage.h>
+
 #include <ModelAPI_Data.h>
 #include <ModelAPI_Validator.h>
 #include <ModelAPI_AttributeDouble.h>
@@ -45,7 +47,7 @@ const double tolerance = 1.e-7;
 
 bool SketchPlugin_DistanceAttrValidator::isValid(const AttributePtr& theAttribute, 
                                                  const std::list<std::string>& theArguments,
-                                                 std::string& theError) const
+                                                 Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeRefAttr::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -70,7 +72,7 @@ bool SketchPlugin_DistanceAttrValidator::isValid(const AttributePtr& theAttribut
       dynamic_cast<const ModelAPI_AttributeValidator*>(aFactory->validator("GeomValidators_ShapeType"));
     std::list<std::string> anArguments;
     anArguments.push_back("circle");
-    std::string aCircleError;
+    Events_InfoMessage aCircleError;
     bool aShapeValid = aShapeValidator->isValid(aRefAttr, anArguments, aCircleError);
     // the circle line is not a valid case
     if (aShapeValid) {
@@ -80,7 +82,7 @@ bool SketchPlugin_DistanceAttrValidator::isValid(const AttributePtr& theAttribut
       
     anArguments.clear();
     anArguments.push_back("line");
-    std::string aLineError;
+    Events_InfoMessage aLineError;
     aShapeValid = aShapeValidator->isValid(aRefAttr, anArguments, aLineError);
     // if the attribute value is not a line, that means it is a vertex. A vertex is always valid
     if (aShapeValid) {
@@ -146,7 +148,7 @@ static bool hasCoincidentPoint(FeaturePtr theFeature1, FeaturePtr theFeature2)
 
 bool SketchPlugin_TangentAttrValidator::isValid(const AttributePtr& theAttribute, 
                                                 const std::list<std::string>& theArguments,
-                                                std::string& theError) const
+                                                Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeRefAttr::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -217,7 +219,7 @@ bool SketchPlugin_TangentAttrValidator::isValid(const AttributePtr& theAttribute
 
 bool SketchPlugin_NotFixedValidator::isValid(const AttributePtr& theAttribute,
                                              const std::list<std::string>& theArguments,
-                                             std::string& theError) const
+                                             Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeRefAttr::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -259,7 +261,7 @@ bool SketchPlugin_NotFixedValidator::isValid(const AttributePtr& theAttribute,
 
 bool SketchPlugin_EqualAttrValidator::isValid(const AttributePtr& theAttribute, 
                                               const std::list<std::string>& theArguments,
-                                              std::string& theError) const
+                                              Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeRefAttr::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -314,7 +316,7 @@ bool SketchPlugin_EqualAttrValidator::isValid(const AttributePtr& theAttribute,
 
 bool SketchPlugin_MirrorAttrValidator::isValid(const AttributePtr& theAttribute, 
                                                const std::list<std::string>& theArguments,
-                                               std::string& theError) const
+                                               Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeRefList::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -343,7 +345,7 @@ bool SketchPlugin_MirrorAttrValidator::isValid(const AttributePtr& theAttribute,
 
 bool SketchPlugin_CoincidenceAttrValidator::isValid(const AttributePtr& theAttribute, 
                                                     const std::list<std::string>& theArguments,
-                                                    std::string& theError) const
+                                                    Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeRefAttr::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -402,7 +404,7 @@ bool SketchPlugin_CoincidenceAttrValidator::isValid(const AttributePtr& theAttri
 
 bool SketchPlugin_CopyValidator::isValid(const AttributePtr& theAttribute, 
                                          const std::list<std::string>& theArguments,
-                                         std::string& theError) const
+                                         Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeRefList::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -442,7 +444,7 @@ bool SketchPlugin_CopyValidator::isValid(const AttributePtr& theAttribute,
 
 bool SketchPlugin_SolverErrorValidator::isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                                                 const std::list<std::string>& theArguments,
-                                                std::string& theError) const
+                                                Events_InfoMessage& theError) const
 {
   AttributeStringPtr aAttributeString = theFeature->string(SketchPlugin_Sketch::SOLVER_ERROR());
 
@@ -500,7 +502,7 @@ static bool hasSameTangentFeature(const std::set<AttributePtr>& theRefsList, con
 
 bool SketchPlugin_FilletVertexValidator::isValid(const AttributePtr& theAttribute,
                                                  const std::list<std::string>& theArguments,
-                                                 std::string& theError) const
+                                                 Events_InfoMessage& theError) const
 {
   std::shared_ptr<SketchPlugin_ConstraintFillet> aFilletFeature = std::dynamic_pointer_cast<SketchPlugin_ConstraintFillet>(theAttribute->owner());
   AttributeRefAttrListPtr aPointsRefList = std::dynamic_pointer_cast<ModelAPI_AttributeRefAttrList>(theAttribute);
@@ -673,7 +675,7 @@ bool SketchPlugin_FilletVertexValidator::isValid(const AttributePtr& theAttribut
 
 bool SketchPlugin_MiddlePointAttrValidator::isValid(const AttributePtr& theAttribute, 
                                                     const std::list<std::string>& theArguments,
-                                                    std::string& theError) const
+                                                    Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeRefAttr::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -719,7 +721,7 @@ bool SketchPlugin_MiddlePointAttrValidator::isValid(const AttributePtr& theAttri
 
 bool SketchPlugin_ArcTangentPointValidator::isValid(const AttributePtr& theAttribute,
                                                     const std::list<std::string>& /*theArguments*/,
-                                                    std::string& theError) const
+                                                    Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeRefAttr::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -773,7 +775,7 @@ bool SketchPlugin_ArcTangentPointValidator::isValid(const AttributePtr& theAttri
 
 bool SketchPlugin_IntersectionValidator::isValid(const AttributePtr& theAttribute,
                                                  const std::list<std::string>& theArguments,
-                                                 std::string& theError) const
+                                                 Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeSelection::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
@@ -819,7 +821,7 @@ bool SketchPlugin_IntersectionValidator::isValid(const AttributePtr& theAttribut
 
 bool SketchPlugin_ProjectionValidator::isValid(const AttributePtr& theAttribute,
                                                const std::list<std::string>& theArguments,
-                                               std::string& theError) const
+                                               Events_InfoMessage& theError) const
 {
   if (theAttribute->attributeType() != ModelAPI_AttributeSelection::typeId()) {
     theError = "The attribute with the " + theAttribute->attributeType() + " type is not processed";
diff --git a/src/SketchPlugin/SketchPlugin_Validators.h b/src/SketchPlugin/SketchPlugin_Validators.h
index f201e1b3a..2ebb8ad76 100644
--- a/src/SketchPlugin/SketchPlugin_Validators.h
+++ b/src/SketchPlugin/SketchPlugin_Validators.h
@@ -26,7 +26,7 @@ class SketchPlugin_DistanceAttrValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /**\class SketchPlugin_TangentAttrValidator
@@ -44,7 +44,7 @@ class SketchPlugin_TangentAttrValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 
@@ -63,7 +63,7 @@ class SketchPlugin_NotFixedValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /**\class SketchPlugin_EqualAttrValidator
@@ -81,7 +81,7 @@ class SketchPlugin_EqualAttrValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /**\class SketchPlugin_MirrorAttrValidator
@@ -99,7 +99,7 @@ class SketchPlugin_MirrorAttrValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 
@@ -118,7 +118,7 @@ class SketchPlugin_CoincidenceAttrValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 
@@ -138,7 +138,7 @@ class SketchPlugin_CopyValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /**\class SketchPlugin_SolverErrorValidator
@@ -156,7 +156,7 @@ class SketchPlugin_SolverErrorValidator : public ModelAPI_FeatureValidator
   //! \param theError error message
   virtual bool isValid(const std::shared_ptr<ModelAPI_Feature>& theFeature,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 
   /// Returns true if the attribute in feature is not obligatory for the feature execution
   virtual bool isNotObligatory(std::string theFeature, std::string theAttribute);
@@ -177,7 +177,7 @@ public:
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 
@@ -196,7 +196,7 @@ class SketchPlugin_MiddlePointAttrValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 
@@ -215,7 +215,7 @@ class SketchPlugin_ArcTangentPointValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /**\class SketchPlugin_IntersectionValidator
@@ -231,7 +231,7 @@ class SketchPlugin_IntersectionValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 /**\class SketchPlugin_ProjectionValidator
@@ -247,7 +247,7 @@ class SketchPlugin_ProjectionValidator : public ModelAPI_AttributeValidator
   //! \param theError error message
   virtual bool isValid(const AttributePtr& theAttribute,
                        const std::list<std::string>& theArguments,
-                       std::string& theError) const;
+                       Events_InfoMessage& theError) const;
 };
 
 #endif
diff --git a/src/XGUI/XGUI_ErrorDialog.cpp b/src/XGUI/XGUI_ErrorDialog.cpp
index 04a3f5316..511d1f578 100644
--- a/src/XGUI/XGUI_ErrorDialog.cpp
+++ b/src/XGUI/XGUI_ErrorDialog.cpp
@@ -60,7 +60,7 @@ void XGUI_ErrorDialog::clear()
 
 void XGUI_ErrorDialog::addError(std::shared_ptr<Events_InfoMessage> theMsg)
 {
-  std::string aError = Config_Translator::translate(theMsg);
+  std::string aError = Config_Translator::translate(*theMsg);
   std::string aCodec = Config_Translator::codec(theMsg->context());
   QString aMsg = QTextCodec::codecForName(aCodec.c_str())->toUnicode(aError.c_str());
   myErrors.append(aMsg);