Add methods to QgsDataDefined for reading and writing to XML

qgis · Dec 10, 2014 · bcc29ff · bcc29ff
1 parent a1e0f01
commit bcc29ff
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Showing 4 changed files with 141 additions and 2 deletions.
diff --git a/python/core/qgsdatadefined.sip b/python/core/qgsdatadefined.sip
@@ -57,5 +57,26 @@ class QgsDataDefined
 
     // @note not available in python bindings
     //QMap< QString, QString > toMap();
+
+    /**Returns a DOM element containing the properties of the data defined container.
+     * @param DOM document
+     * @param elementName name for DOM element
+     * @returns DOM element corresponding to data defined container
+     * @note added in QGIS 2.7
+     * @see setFromXmlElement
+     */
+    QDomElement toXmlElement( QDomDocument &document, const QString &elementName ) const;
+
+    /**Sets the properties of the data defined container from an XML element. Calling
+     * this will overwrite all the current properties of the container.
+     * @param element DOM element
+     * @returns true if properties were successfully read from element
+     * @note added in QGIS 2.7
+     * @see toXmlElement
+     */
+    bool setFromXmlElement( const QDomElement& element );
+
+    bool operator==( const QgsDataDefined &other );
+    bool operator!=( const QgsDataDefined &other );
 
 };
diff --git a/src/core/qgsdatadefined.cpp b/src/core/qgsdatadefined.cpp
@@ -23,8 +23,8 @@
 QgsDataDefined::QgsDataDefined( bool active,
                                 bool useexpr,
                                 const QString& expr,
-                                const QString& field ) :
-    mActive( active )
+                                const QString& field )
+    : mActive( active )
     , mUseExpression( useexpr )
     , mExpressionString( expr )
     , mField( field )
@@ -136,3 +136,38 @@ QMap< QString, QString > QgsDataDefined::toMap()
 
   return map;
 }
+
+QDomElement QgsDataDefined::toXmlElement( QDomDocument &document, const QString& elementName ) const
+{
+  QDomElement element = document.createElement( elementName );
+  element.setAttribute( "active", mActive ? "true" : "false" );
+  element.setAttribute( "useExpr", mUseExpression ? "true" : "false" );
+  element.setAttribute( "expr", mExpressionString );
+  element.setAttribute( "field", mField );
+  return element;
+}
+
+bool QgsDataDefined::setFromXmlElement( const QDomElement &element )
+{
+  if ( element.isNull() )
+  {
+    return false;
+  }
+
+  mActive = element.attribute( "active" ).compare( "true", Qt::CaseInsensitive ) == 0;
+  mUseExpression = element.attribute( "useExpr" ).compare( "true", Qt::CaseInsensitive ) == 0;
+  mField = element.attribute( "field" );
+  setExpressionString( element.attribute( "expr" ) );
+  return true;
+}
+
+bool QgsDataDefined::operator==( const QgsDataDefined &other )
+{
+  return other.isActive() == mActive && other.useExpression() == mUseExpression &&
+         other.field() == mField && other.expressionString() == mExpressionString;
+}
+
+bool QgsDataDefined::operator!=( const QgsDataDefined &other )
+{
+  return !( *this == other );
+}
diff --git a/src/core/qgsdatadefined.h b/src/core/qgsdatadefined.h
@@ -80,6 +80,27 @@ class CORE_EXPORT QgsDataDefined
     // @note not available in python bindings
     QMap< QString, QString > toMap();
 
+    /**Returns a DOM element containing the properties of the data defined container.
+     * @param DOM document
+     * @param elementName name for DOM element
+     * @returns DOM element corresponding to data defined container
+     * @note added in QGIS 2.7
+     * @see setFromXmlElement
+     */
+    QDomElement toXmlElement( QDomDocument &document, const QString &elementName ) const;
+
+    /**Sets the properties of the data defined container from an XML element. Calling
+     * this will overwrite all the current properties of the container.
+     * @param element DOM element
+     * @returns true if properties were successfully read from element
+     * @note added in QGIS 2.7
+     * @see toXmlElement
+     */
+    bool setFromXmlElement( const QDomElement& element );
+
+    bool operator==( const QgsDataDefined &other );
+    bool operator!=( const QgsDataDefined &other );
+
   private:
     QgsExpression* mExpression;
 

diff --git a/tests/src/core/testqgsdatadefined.cpp b/tests/src/core/testqgsdatadefined.cpp
@@ -35,6 +35,8 @@ class TestQgsDataDefined: public QObject
     void create();//test creating a data defined container
     void gettersSetters(); //test getters and setters
     void defaultValues(); //test hasDefaultValues method
+    void equality(); //test equality operators
+    void xmlMethods(); //test saving and reading from xml
 
   private:
 };
@@ -110,5 +112,65 @@ void TestQgsDataDefined::defaultValues()
   delete dd;
 }
 
+void TestQgsDataDefined::equality()
+{
+  QgsDataDefined dd1;
+  dd1.setActive( true );
+  dd1.setField( QString( "field" ) );
+  dd1.setExpressionString( QString( "expression" ) );
+  dd1.setUseExpression( true );
+  QgsDataDefined dd2;
+  dd2.setActive( true );
+  dd2.setField( QString( "field" ) );
+  dd2.setExpressionString( QString( "expression" ) );
+  dd2.setUseExpression( true );
+  QVERIFY( dd1 == dd2 );
+  QVERIFY( !( dd1 != dd2 ) );
+
+  //test that all applicable components contribute to equality
+  dd2.setActive( false );
+  QVERIFY( !( dd1 == dd2 ) );
+  QVERIFY( dd1 != dd2 );
+  dd2.setActive( true );
+  dd2.setField( QString( "a" ) );
+  QVERIFY( !( dd1 == dd2 ) );
+  QVERIFY( dd1 != dd2 );
+  dd2.setField( QString( "field" ) );
+  dd2.setExpressionString( QString( "b" ) );
+  QVERIFY( !( dd1 == dd2 ) );
+  QVERIFY( dd1 != dd2 );
+  dd2.setExpressionString( QString( "expression" ) );
+  dd2.setUseExpression( false );
+  QVERIFY( !( dd1 == dd2 ) );
+  QVERIFY( dd1 != dd2 );
+}
+
+void TestQgsDataDefined::xmlMethods()
+{
+  //create a test dom element
+  QDomImplementation DomImplementation;
+  QDomDocumentType documentType =
+    DomImplementation.createDocumentType(
+      "qgis", "http://mrcc.com/qgis.dtd", "SYSTEM" );
+  QDomDocument doc( documentType );
+
+  QgsDataDefined dd1;
+  dd1.setActive( true );
+  dd1.setField( QString( "field" ) );
+  dd1.setExpressionString( QString( "expression" ) );
+  dd1.setUseExpression( true );
+  QDomElement ddElem = dd1.toXmlElement( doc, "test" );
+
+  //test reading
+  QgsDataDefined dd2;
+  QVERIFY( dd2 != dd1 );
+  QVERIFY( dd2.setFromXmlElement( ddElem ) );
+  QVERIFY( dd2 == dd1 );
+
+  //test reading from null element
+  QDomElement badElem;
+  QVERIFY( !dd2.setFromXmlElement( badElem ) );
+}
+
 QTEST_MAIN( TestQgsDataDefined )
 #include "testqgsdatadefined.moc"