add constraint description

python/core/qgseditformconfig.sip

@@ -492,6 +492,22 @@ class QgsEditFormConfig : QObject
      */
     void setExpression( int idx, const QString& str );
 
+    /**
+     * Returns the constraint expression description of a specific filed.
+     * @param idx The index of the field
+     * @return the expression description
+     * @note added in QGIS 2.16
+     */
+    QString expressionDescription( int idx ) const;
+
+    /**
+     * Set the constraint expression description for a specific field.
+     * @param idx The index of the field
+     * @param descr The description of the expression
+     * @note added in QGIS 2.16
+     */
+    void setExpressionDescription( int idx, const QString &descr );
+
     /**
      * Returns if the field at fieldidx should be treated as NOT NULL value
      */

python/gui/editorwidgets/core/qgseditorwidgetwrapper.sip

@@ -115,6 +115,7 @@ class QgsEditorWidgetWrapper : QgsWidgetWrapper
      * Emit this signal when the constraint status changed.
      * @brief constraintStatusChanged
      * @param constraint represented as a string
+     * @param desc is the constraint description
      * @param err the error represented as a string. Empty if none.
      * @param status
      */

src/app/qgsattributetypedialog.cpp

@@ -180,6 +180,16 @@ bool QgsAttributeTypeDialog::labelOnTop() const
   return labelOnTopCheckBox->isChecked();
 }
 
+void QgsAttributeTypeDialog::setExpressionDescription( const QString &desc )
+{
+  constraintExpressionDescription->setText( desc );
+}
+
+QString QgsAttributeTypeDialog::expressionDescription()
+{
+  return constraintExpressionDescription->text();
+}
+
 bool QgsAttributeTypeDialog::notNull() const
 {
   return notNullCheckBox->isChecked();

src/app/qgsattributetypedialog.h

@@ -85,7 +85,7 @@ class APP_EXPORT QgsAttributeTypeDialog: public QDialog, private Ui::QgsAttribut
     bool fieldEditable() const;
 
     /**
-     * Getter for checkbox for not null
+     * Setter for checkbox for not null
      */
     void setNotNull( bool notNull );
 
@@ -94,6 +94,20 @@ class APP_EXPORT QgsAttributeTypeDialog: public QDialog, private Ui::QgsAttribut
      */
     bool notNull() const;
 
+    /*
+     * Setter for constraint expression description
+     * @param desc the expression description
+     * @note added in QGIS 2.16
+     **/
+    void setExpressionDescription( const QString &desc );
+
+    /*
+     * Getter for constraint expression description
+     * @return the expression description
+     * @note added in QGIS 2.16
+     **/
+    QString expressionDescription();
+
     /**
      * Getter for the constraint expression
      * @note added in QGIS 2.16

src/app/qgsfieldsproperties.cpp

@@ -529,6 +529,7 @@ void QgsFieldsProperties::attributeTypeDialog()
   attributeTypeDialog.setLabelOnTop( cfg.mLabelOnTop );
   attributeTypeDialog.setNotNull( cfg.mNotNull );
   attributeTypeDialog.setExpression( cfg.mConstraint );
+  attributeTypeDialog.setExpressionDescription( cfg.mConstraintDescription );
 
   attributeTypeDialog.setWidgetV2Config( cfg.mEditorWidgetV2Config );
   attributeTypeDialog.setWidgetV2Type( cfg.mEditorWidgetV2Type );
@@ -539,6 +540,7 @@ void QgsFieldsProperties::attributeTypeDialog()
   cfg.mEditable = attributeTypeDialog.fieldEditable();
   cfg.mLabelOnTop = attributeTypeDialog.labelOnTop();
   cfg.mNotNull = attributeTypeDialog.notNull();
+  cfg.mConstraintDescription = attributeTypeDialog.expressionDescription();
   cfg.mConstraint = attributeTypeDialog.expression();
 
   cfg.mEditorWidgetV2Type = attributeTypeDialog.editorWidgetV2Type();
@@ -913,6 +915,7 @@ void QgsFieldsProperties::apply()
     mLayer->editFormConfig()->setReadOnly( i, !cfg.mEditable );
     mLayer->editFormConfig()->setLabelOnTop( i, cfg.mLabelOnTop );
     mLayer->editFormConfig()->setNotNull( i, cfg.mNotNull );
+    mLayer->editFormConfig()->setExpressionDescription( i, cfg.mConstraintDescription );
     mLayer->editFormConfig()->setExpression( i, cfg.mConstraint );
 
     mLayer->editFormConfig()->setWidgetType( idx, cfg.mEditorWidgetV2Type );
@@ -981,6 +984,7 @@ QgsFieldsProperties::FieldConfig::FieldConfig()
     , mEditableEnabled( true )
     , mLabelOnTop( false )
     , mNotNull( false )
+    , mConstraintDescription( QString() )
     , mButton( nullptr )
 {
 }
@@ -994,6 +998,7 @@ QgsFieldsProperties::FieldConfig::FieldConfig( QgsVectorLayer* layer, int idx )
   mLabelOnTop = layer->editFormConfig()->labelOnTop( idx );
   mNotNull = layer->editFormConfig()->notNull( idx );
   mConstraint = layer->editFormConfig()->expression( idx );
+  mConstraintDescription = layer->editFormConfig()->expressionDescription( idx );
   mEditorWidgetV2Type = layer->editFormConfig()->widgetType( idx );
   mEditorWidgetV2Config = layer->editFormConfig()->widgetConfig( idx );
 

src/app/qgsfieldsproperties.h

@@ -94,6 +94,7 @@ class APP_EXPORT QgsFieldsProperties : public QWidget, private Ui_QgsFieldsPrope
         bool mLabelOnTop;
         bool mNotNull;
         QString mConstraint;
+        QString mConstraintDescription;
         QPushButton* mButton;
         QString mEditorWidgetV2Type;
         QMap<QString, QVariant> mEditorWidgetV2Config;

src/core/qgseditformconfig.cpp

@@ -135,6 +135,22 @@ void QgsEditFormConfig::setExpression( int idx, const QString& str )
     mConstraints[ mFields.at( idx ).name()] = str;
 }
 
+QString QgsEditFormConfig::expressionDescription( int idx ) const
+{
+  QString description;
+
+  if ( idx >= 0 && idx < mFields.count() )
+    description = mConstraintsDescription[ mFields.at( idx ).name()];
+
+  return description;
+}
+
+void QgsEditFormConfig::setExpressionDescription( int idx, const QString &descr )
+{
+  if ( idx >= 0 && idx < mFields.count() )
+    mConstraintsDescription[ mFields.at( idx ).name()] = descr;
+}
+
 bool QgsEditFormConfig::notNull( int idx ) const
 {
   if ( idx >= 0 && idx < mFields.count() )

src/core/qgseditformconfig.h

@@ -484,12 +484,12 @@ class CORE_EXPORT QgsEditFormConfig : public QObject
     QgsEditorWidgetConfig widgetConfig( const QString& widgetName ) const;
 
     /**
-     * Remove the configuration for the editor widget used to represent the field at the given index
+    * Remove the configuration for the editor widget used to represent the field at the given index
-     *
+    *
-     * @param fieldIdx  The index of the field
+    * @param fieldIdx  The index of the field
-     *
+    *
-     * @return true if successful, false if the field does not exist
+    * @return true if successful, false if the field does not exist
-     */
+    */
     bool removeWidgetConfig( int fieldIdx );
 
     /**
@@ -528,6 +528,22 @@ class CORE_EXPORT QgsEditFormConfig : public QObject
      */
     void setExpression( int idx, const QString& str );
 
+    /**
+     * Returns the constraint expression description of a specific filed.
+     * @param idx The index of the field
+     * @return the expression description
+     * @note added in QGIS 2.16
+     */
+    QString expressionDescription( int idx ) const;
+
+    /**
+     * Set the constraint expression description for a specific field.
+     * @param idx The index of the field
+     * @param descr The description of the expression
+     * @note added in QGIS 2.16
+     */
+    void setExpressionDescription( int idx, const QString &descr );
+
     /**
      * Returns if the field at fieldidx should be treated as NOT NULL value
      */
@@ -657,6 +673,7 @@ class CORE_EXPORT QgsEditFormConfig : public QObject
     QList< TabData > mTabs;
 
     QMap< QString, QString> mConstraints;
+    QMap< QString, QString> mConstraintsDescription;
     QMap< QString, bool> mFieldEditables;
     QMap< QString, bool> mLabelOnTop;
     QMap< QString, bool> mNotNull;

src/gui/editorwidgets/core/qgseditorwidgetregistry.cpp

@@ -253,6 +253,7 @@ void QgsEditorWidgetRegistry::readMapLayer( QgsMapLayer* mapLayer, const QDomEle
       vectorLayer->editFormConfig()->setLabelOnTop( idx, ewv2CfgElem.attribute( "labelOnTop", "0" ) == "1" );
       vectorLayer->editFormConfig()->setNotNull( idx, ewv2CfgElem.attribute( "notNull", "0" ) == "1" );
       vectorLayer->editFormConfig()->setExpression( idx, ewv2CfgElem.attribute( "constraint", QString() ) );
+      vectorLayer->editFormConfig()->setExpressionDescription( idx, ewv2CfgElem.attribute( "constraintDescription", QString() ) );
 
       vectorLayer->editFormConfig()->setWidgetConfig( idx, cfg );
     }
@@ -312,6 +313,7 @@ void QgsEditorWidgetRegistry::writeMapLayer( QgsMapLayer* mapLayer, QDomElement&
       ewv2CfgElem.setAttribute( "labelOnTop", vectorLayer->editFormConfig()->labelOnTop( idx ) );
       ewv2CfgElem.setAttribute( "notNull", vectorLayer->editFormConfig()->notNull( idx ) );
       ewv2CfgElem.setAttribute( "constraint", vectorLayer->editFormConfig()->expression( idx ) );
+      ewv2CfgElem.setAttribute( "constraintDescription", vectorLayer->editFormConfig()->expressionDescription( idx ) );
 
       mWidgetFactories[widgetType]->writeConfig( vectorLayer->editFormConfig()->widgetConfig( idx ), ewv2CfgElem, doc, vectorLayer, idx );
 

src/gui/editorwidgets/core/qgseditorwidgetwrapper.cpp

@@ -108,10 +108,13 @@ void QgsEditorWidgetWrapper::updateConstraint( const QgsFeature &ft )
   bool toEmit( false );
   QString errStr( tr( "predicate is True" ) );
   QString expression = layer()->editFormConfig()->expression( mFieldIdx );
+  QString description;
   QVariant value = ft.attribute( mFieldIdx );
 
   if ( ! expression.isEmpty() )
   {
+    description = layer()->editFormConfig()->expressionDescription( mFieldIdx );
+
     QgsExpressionContext context =
       QgsExpressionContextUtils::createFeatureBasedContext( ft, *ft.fields() );
     context << QgsExpressionContextUtils::layerScope( layer() );
@@ -139,9 +142,13 @@ void QgsEditorWidgetWrapper::updateConstraint( const QgsFeature &ft )
     {
       QString fieldName = ft.fields()->field( mFieldIdx ).name();
       expression = "( " + expression + " ) AND ( " + fieldName + " IS NOT NULL)";
+      description = "( " + description + " ) AND NotNull";
     }
     else
+    {
+      description = "NotNull";
       expression = "NotNull";
+    }
 
     mValidConstraint = mValidConstraint && !value.isNull();
 
@@ -154,7 +161,7 @@ void QgsEditorWidgetWrapper::updateConstraint( const QgsFeature &ft )
   if ( toEmit )
   {
     updateConstraintWidgetStatus();
-    emit constraintStatusChanged( expression, errStr, mValidConstraint );
+    emit constraintStatusChanged( expression, description, errStr, mValidConstraint );
   }
 }
 

src/gui/editorwidgets/core/qgseditorwidgetwrapper.h

@@ -137,10 +137,11 @@ class GUI_EXPORT QgsEditorWidgetWrapper : public QgsWidgetWrapper
      * Emit this signal when the constraint status changed.
      * @brief constraintStatusChanged
      * @param constraint represented as a string
+     * @param desc is the constraint description
      * @param err the error represented as a string. Empty if none.
      * @param status
      */
-    void constraintStatusChanged( const QString& constraint, const QString& err, bool status );
+    void constraintStatusChanged( const QString& constraint, const QString &desc, const QString& err, bool status );
 
   public slots:
     /**

src/gui/qgsattributeform.cpp

@@ -795,17 +795,26 @@ void QgsAttributeForm::clearInvalidConstraintsMessage()
   }
 }
 
-void QgsAttributeForm::displayInvalidConstraintMessage( const QStringList &f )
+void QgsAttributeForm::displayInvalidConstraintMessage( const QStringList &f,
+    const QStringList &d )
 {
   clearInvalidConstraintsMessage();
 
+  // show only the third first error
+  int max = 3;
+  int size = f.size() > max ? max : f.size();
+  QString descriptions;
+  for ( int i = 0; i < size; i++ )
+    descriptions += "<br />- " + f[i] + ": " + d[i];
+
   mInvalidConstraintMessageBarItem =
-    new QgsMessageBarItem( tr( "Invalid fields:" ),
+    new QgsMessageBarItem( tr( "Invalid fields: " ),
-                           f.join( ", " ), QgsMessageBar::WARNING );
+                           descriptions, QgsMessageBar::WARNING );
   mMessageBar->pushItem( mInvalidConstraintMessageBarItem );
 }
 
-bool QgsAttributeForm::currentFormValidConstraints( QStringList &invalidFields )
+bool QgsAttributeForm::currentFormValidConstraints( QStringList &invalidFields,
+    QStringList &descriptions )
 {
   bool valid( true );
 
@@ -817,6 +826,10 @@ bool QgsAttributeForm::currentFormValidConstraints( QStringList &invalidFields )
       if ( ! eww->isValidConstraint() )
       {
         invalidFields.append( eww->field().name() );
+
+        QString desc = eww->layer()->editFormConfig()->expressionDescription( eww->fieldIdx() );
+        descriptions.append( desc );
+
         valid = false; // continue to get all invalif fields
       }
     }
@@ -883,7 +896,7 @@ void QgsAttributeForm::onUpdatedFields()
 }
 
 void QgsAttributeForm::onConstraintStatusChanged( const QString& constraint,
-    const QString& err, bool ok )
+    const QString &description, const QString& err, bool ok )
 {
   QgsEditorWidgetWrapper* eww = qobject_cast<QgsEditorWidgetWrapper*>( sender() );
   Q_ASSERT( eww );
@@ -892,7 +905,8 @@ void QgsAttributeForm::onConstraintStatusChanged( const QString& constraint,
 
   if ( buddy )
   {
-    QString tooltip = tr( "Expression: " ) + constraint + "\n" + tr( "Constraint: " ) + err;
+    QString tooltip = tr( "Description: " ) + description + "\n" +
+                      tr( "Raw expression: " ) + constraint + "\n" + tr( "Constraint: " ) + err;
     buddy->setToolTip( tooltip );
 
     if ( !buddy->property( "originalText" ).isValid() )
@@ -986,11 +1000,11 @@ void QgsAttributeForm::synchronizeEnabledState()
   // push a message and disable the OK button if constraints are invalid
   clearInvalidConstraintsMessage();
 
-  QStringList invalidFields;
+  QStringList invalidFields, descriptions;
-  bool validConstraint = currentFormValidConstraints( invalidFields );
+  bool validConstraint = currentFormValidConstraints( invalidFields, descriptions );
 
   if ( ! validConstraint )
-    displayInvalidConstraintMessage( invalidFields );
+    displayInvalidConstraintMessage( invalidFields, descriptions );
 
   isEditable = isEditable & validConstraint;
 
@@ -1205,7 +1219,6 @@ void QgsAttributeForm::init()
   }
   mButtonBox->setVisible( buttonBoxVisible );
 
-<<<<<<< HEAD
   if ( !mSearchButtonBox )
   {
     mSearchButtonBox = new QWidget();
@@ -1618,7 +1631,8 @@ void QgsAttributeForm::afterWidgetInit()
       }
 
       connect( eww, SIGNAL( valueChanged( const QVariant& ) ), this, SLOT( onAttributeChanged( const QVariant& ) ) );
-      connect( eww, SIGNAL( constraintStatusChanged( QString, QString, bool ) ), this, SLOT( onConstraintStatusChanged( QString, QString, bool ) ) );
+      connect( eww, SIGNAL( constraintStatusChanged( QString, QString, QString, bool ) ),
+               this, SLOT( onConstraintStatusChanged( QString, QString, QString, bool ) ) );
     }
   }
 

src/gui/qgsattributeform.h

@@ -234,8 +234,8 @@ class GUI_EXPORT QgsAttributeForm : public QWidget
     void onAttributeAdded( int idx );
     void onAttributeDeleted( int idx );
     void onUpdatedFields();
-    void onConstraintStatusChanged( const QString& constraint, const QString& err, bool ok );
+    void onConstraintStatusChanged( const QString& constraint,
-
+                                    const QString &description, const QString& err, bool ok );
     void preventFeatureRefresh();
     void synchronizeEnabledState();
     void layerSelectionChanged();
@@ -302,10 +302,11 @@ class GUI_EXPORT QgsAttributeForm : public QWidget
     void updateAllConstaints();
     void updateConstraints( QgsEditorWidgetWrapper *w );
     bool currentFormFeature( QgsFeature &feature );
-    bool currentFormValidConstraints( QStringList &invalidFields );
+    bool currentFormValidConstraints( QStringList &invalidFields, QStringList &descriptions );
     void constraintDependencies( QgsEditorWidgetWrapper *w, QList<QgsEditorWidgetWrapper*> &wDeps );
     void clearInvalidConstraintsMessage();
-    void displayInvalidConstraintMessage( const QStringList &invalidFields );
+    void displayInvalidConstraintMessage( const QStringList &invalidFields,
+                                          const QStringList &description );
     void displayNullFieldsMessage();
     QgsMessageBarItem *mInvalidConstraintMessageBarItem;
     QgsMessageBarItem *mFieldNotInitializedMessageBarItem;

src/ui/qgsattributetypeedit.ui

@@ -74,6 +74,23 @@
      </item>
     </layout>
    </item>
+   <item row="5" column="1">
+    <layout class="QHBoxLayout" name="horizontalLayout">
+     <property name="bottomMargin">
+      <number>0</number>
+     </property>
+     <item>
+      <widget class="QLabel" name="label_2">
+       <property name="text">
+        <string>Constraint description</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QLineEdit" name="constraintExpressionDescription"/>
+     </item>
+    </layout>
+   </item>
   </layout>
  </widget>
  <customwidgets>