[FEATURE][composer] Data defined url for composer html items. Sponsored by City of Uster, Switzerland.

Author: nyalldawson

python/core/composer/qgscomposerhtml.sip

@@ -152,4 +152,9 @@ class QgsComposerHtml: QgsComposerMultiFrame
      * @see url
      */
     void loadHtml();
+    
+    void refreshExpressionContext();
+    
+    virtual void refreshDataDefinedProperty( QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
+
 };

python/core/composer/qgscomposermultiframe.sip

@@ -84,4 +84,9 @@ class QgsComposerMultiFrame: QgsComposerObject
 
   signals:
     void changed();
+    
+    /**Emitted when the contents of the multi frame have changed and the frames
+     * must be redrawn.
+    */
+    void contentsChanged();
 };

src/app/composer/qgscomposerhtmlwidget.cpp

@@ -45,6 +45,15 @@ QgsComposerHtmlWidget::QgsComposerHtmlWidget( QgsComposerHtml* html, QgsComposer
   if ( mHtml )
   {
     QObject::connect( mHtml, SIGNAL( changed() ), this, SLOT( setGuiElementValues() ) );
+
+    QgsAtlasComposition* atlas = atlasComposition();
+    if ( atlas )
+    {
+      // repopulate data defined buttons if atlas layer changes
+      connect( atlas, SIGNAL( coverageLayerChanged( QgsVectorLayer* ) ),
+               this, SLOT( populateDataDefinedButtons() ) );
+      connect( atlas, SIGNAL( toggled( bool ) ), this, SLOT( populateDataDefinedButtons() ) );
+    }
   }
 
   //embed widget for general options
@@ -54,6 +63,12 @@ QgsComposerHtmlWidget::QgsComposerHtmlWidget( QgsComposerHtml* html, QgsComposer
     QgsComposerItemWidget* itemPropertiesWidget = new QgsComposerItemWidget( this, mFrame );
     mainLayout->addWidget( itemPropertiesWidget );
   }
+
+  //connections for data defined buttons
+  connect( mUrlDDBtn, SIGNAL( dataDefinedChanged( const QString& ) ), this, SLOT( updateDataDefinedProperty( ) ) );
+  connect( mUrlDDBtn, SIGNAL( dataDefinedActivated( bool ) ), this, SLOT( updateDataDefinedProperty( ) ) );
+  connect( mUrlDDBtn, SIGNAL( dataDefinedActivated( bool ) ), mUrlLineEdit, SLOT( setDisabled( bool ) ) );
+
 }
 
 QgsComposerHtmlWidget::QgsComposerHtmlWidget(): QgsComposerItemBaseWidget( 0, 0 )
@@ -358,5 +373,35 @@ void QgsComposerHtmlWidget::setGuiElementValues()
   mRadioManualSource->setChecked( mHtml->contentMode() == QgsComposerHtml::ManualHtml );
   mHtmlEditor->setEnabled( mHtml->contentMode() == QgsComposerHtml::ManualHtml );
   mInsertExpressionButton->setEnabled( mHtml->contentMode() == QgsComposerHtml::ManualHtml );
+
+  populateDataDefinedButtons();
+
   blockSignals( false );
 }
+
+QgsComposerItem::DataDefinedProperty QgsComposerHtmlWidget::ddPropertyForWidget( QgsDataDefinedButton *widget )
+{
+  if ( widget == mUrlDDBtn )
+  {
+    return QgsComposerItem::SourceUrl;
+  }
+  return QgsComposerItem::NoProperty;
+}
+
+void QgsComposerHtmlWidget::populateDataDefinedButtons()
+{
+  QgsVectorLayer* vl = atlasCoverageLayer();
+
+  //block signals from data defined buttons
+  mUrlDDBtn->blockSignals( true );
+
+  //initialise buttons to use atlas coverage layer
+  mUrlDDBtn->init( vl, mHtml->dataDefinedProperty( QgsComposerItem::SourceUrl ),
+                   QgsDataDefinedButton::AnyType, tr( "url string" ) );
+
+  //initial state of controls - disable related controls when dd buttons are active
+  mUrlLineEdit->setEnabled( !mUrlDDBtn->isActive() );
+
+  //unblock signals from data defined buttons
+  mUrlDDBtn->blockSignals( false );
+}

src/app/composer/qgscomposerhtmlwidget.h

@@ -47,6 +47,13 @@ class QgsComposerHtmlWidget: public QgsComposerItemBaseWidget, private Ui::QgsCo
     /**Sets the GUI elements to the values of mHtmlItem*/
     void setGuiElementValues();
 
+  protected:
+    QgsComposerItem::DataDefinedProperty ddPropertyForWidget( QgsDataDefinedButton *widget );
+
+  protected slots:
+    /**Initializes data defined buttons to current atlas coverage layer*/
+    void populateDataDefinedButtons();
+
   private:
     QgsComposerHtmlWidget();
     void blockSignals( bool block );

src/core/composer/qgscomposerframe.cpp

@@ -21,6 +21,8 @@ QgsComposerFrame::QgsComposerFrame( QgsComposition* c, QgsComposerMultiFrame* mf
     : QgsComposerItem( x, y, width, height, c )
     , mMultiFrame( mf )
 {
+  //repaint frame when multiframe content changes
+  connect( mf, SIGNAL( contentsChanged() ), this, SLOT( repaint() ) );
 }
 
 QgsComposerFrame::QgsComposerFrame()
@@ -41,6 +43,7 @@ bool QgsComposerFrame::writeXML( QDomElement& elem, QDomDocument & doc ) const
   frameElem.setAttribute( "sectionWidth", QString::number( mSection.width() ) );
   frameElem.setAttribute( "sectionHeight", QString::number( mSection.height() ) );
   elem.appendChild( frameElem );
+
   return _writeXML( frameElem, doc );
 }
 

src/core/composer/qgscomposerhtml.cpp

@@ -20,6 +20,7 @@
 #include "qgsnetworkaccessmanager.h"
 #include "qgsmessagelog.h"
 #include "qgsexpression.h"
+#include "qgslogger.h"
 
 #include <QCoreApplication>
 #include <QPainter>
@@ -47,9 +48,11 @@ QgsComposerHtml::QgsComposerHtml( QgsComposition* c, bool createUndoCommands ):
   if ( mComposition )
   {
     QObject::connect( mComposition, SIGNAL( itemRemoved( QgsComposerItem* ) ), this, SLOT( handleFrameRemoval( QgsComposerItem* ) ) );
-    connect( mComposition, SIGNAL( refreshItemsTriggered() ), this, SLOT( loadHtml() ) );
   }
 
+  // data defined strings
+  mDataDefinedNames.insert( QgsComposerObject::SourceUrl, QString( "dataDefinedSourceUrl" ) );
+
   if ( mComposition && mComposition->atlasMode() == QgsComposition::PreviewAtlas )
   {
     //a html item added while atlas preview is enabled needs to have the expression context set,
@@ -152,12 +155,13 @@ QString QgsComposerHtml::fetchHtml( QUrl url )
 
   QByteArray array = reply->readAll();
   reply->deleteLater();
-  return QString( array );
+  mFetchedHtml = QString( array );
+  return mFetchedHtml;
 }
 
 void QgsComposerHtml::loadHtml()
 {
-  if ( !mWebPage || ( mContentMode == QgsComposerHtml::Url && mUrl.isEmpty() ) )
+  if ( !mWebPage )
   {
     return;
   }
@@ -167,7 +171,29 @@ void QgsComposerHtml::loadHtml()
   {
     case QgsComposerHtml::Url:
     {
-      loadedHtml = fetchHtml( mUrl );
+
+      QString currentUrl = mUrl.toString();
+
+      //data defined url set?
+      QVariant exprVal;
+      if ( dataDefinedEvaluate( QgsComposerObject::SourceUrl, exprVal ) )
+      {
+        currentUrl = exprVal.toString().trimmed();;
+        QgsDebugMsg( QString( "exprVal Source Url:%1" ).arg( currentUrl ) );
+      }
+      if ( currentUrl.isEmpty() )
+      {
+        return;
+      }
+      if ( currentUrl != mLastFetchedUrl )
+      {
+        loadedHtml = fetchHtml( QUrl( currentUrl ) );
+        mLastFetchedUrl = currentUrl;
+      }
+      else
+      {
+        loadedHtml = mFetchedHtml;
+      }
       break;
     }
     case QgsComposerHtml::ManualHtml:
@@ -183,7 +209,7 @@ void QgsComposerHtml::loadHtml()
 
   mLoaded = false;
   //set html, using the specified url as base if in Url mode
-  mWebPage->mainFrame()->setHtml( loadedHtml, mContentMode == QgsComposerHtml::Url ? QUrl( mUrl ) : QUrl() );
+  mWebPage->mainFrame()->setHtml( loadedHtml, mContentMode == QgsComposerHtml::Url ? QUrl( mLastFetchedUrl ) : QUrl() );
 
   while ( !mLoaded )
   {
@@ -214,6 +240,8 @@ void QgsComposerHtml::loadHtml()
 
   recalculateFrameSizes();
   emit changed();
+  //trigger a repaint
+  emit contentsChanged();
 }
 
 void QgsComposerHtml::frameLoaded( bool ok )
@@ -455,3 +483,13 @@ void QgsComposerHtml::refreshExpressionContext()
   setExpressionContext( feature, vl );
   loadHtml();
 }
+
+void QgsComposerHtml::refreshDataDefinedProperty( QgsComposerObject::DataDefinedProperty property )
+{
+  //updates data defined properties and redraws item to match
+  if ( property == QgsComposerObject::SourceUrl || property == QgsComposerObject::AllProperties )
+  {
+    loadHtml();
+  }
+  QgsComposerObject::refreshDataDefinedProperty( property );
+}

src/core/composer/qgscomposerhtml.h

@@ -178,6 +178,8 @@ class CORE_EXPORT QgsComposerHtml: public QgsComposerMultiFrame
 
     void refreshExpressionContext();
 
+    virtual void refreshDataDefinedProperty( QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
+
   private slots:
     void frameLoaded( bool ok = true );
 
@@ -186,6 +188,8 @@ class CORE_EXPORT QgsComposerHtml: public QgsComposerMultiFrame
     QUrl mUrl;
     QWebPage* mWebPage;
     QString mHtml;
+    QString mFetchedHtml;
+    QString mLastFetchedUrl;
     bool mLoaded;
     QSizeF mSize; //total size in mm
     double mHtmlUnitsToMM;

src/core/composer/qgscomposermultiframe.h

@@ -122,6 +122,11 @@ class CORE_EXPORT QgsComposerMultiFrame: public QgsComposerObject
 
   signals:
     void changed();
+
+    /**Emitted when the contents of the multi frame have changed and the frames
+     * must be redrawn.
+    */
+    void contentsChanged();
 };
 
 #endif // QGSCOMPOSERMULTIFRAME_H

src/core/composer/qgscomposerobject.h

@@ -65,7 +65,9 @@ class CORE_EXPORT QgsComposerObject: public QObject
       MapXMax, /*< map extent x maximum */
       MapYMax, /*< map extent y maximum */
       //composer picture
-      PictureSource /*< picture source url */
+      PictureSource, /*< picture source url */
+      //html item
+      SourceUrl /*< html source utl */
     };
 
     /** Specifies whether the value returned by a function should be the original, user

src/ui/qgscomposerhtmlwidgetbase.ui

@@ -92,6 +92,13 @@
               </property>
              </widget>
             </item>
+            <item>
+             <widget class="QgsDataDefinedButton" name="mUrlDDBtn">
+              <property name="text">
+               <string>...</string>
+              </property>
+             </widget>
+            </item>
            </layout>
           </item>
           <item row="2" column="0" colspan="2">
@@ -220,6 +227,11 @@
    <header>qgscollapsiblegroupbox.h</header>
    <container>1</container>
   </customwidget>
+  <customwidget>
+   <class>QgsDataDefinedButton</class>
+   <extends>QToolButton</extends>
+   <header>qgsdatadefinedbutton.h</header>
+  </customwidget>
  </customwidgets>
  <resources/>
  <connections/>