Yay, more QML!

python/core/auto_generated/qgsattributeeditorelement.sip.in

@@ -348,6 +348,11 @@ Determines if the "unlink feature" button should be shown
 
 class QgsAttributeEditorQmlElement : QgsAttributeEditorElement
 {
+%Docstring
+An attribute editor widget that will represent arbitrary QML code.
+
+.. versionadded:: 3.4
+%End
 
 %TypeHeaderCode
 #include "qgsattributeeditorelement.h"
@@ -355,8 +360,22 @@ class QgsAttributeEditorQmlElement : QgsAttributeEditorElement
   public:
     QgsAttributeEditorQmlElement( QgsAttributeEditorElement *parent );
 
+    virtual QgsAttributeEditorElement *clone( QgsAttributeEditorElement *parent ) const /Factory/;
+
+
     QString qmlCode() const;
+%Docstring
+The QML code that will be represented within this widget.
+
+.. versionadded:: 3.4
+%End
+
     void setQmlCode( const QString &qmlCode );
+%Docstring
+The QML code that will be represented within this widget.
+
+@param qmlCode
+%End
 
 };
 

src/app/qgsattributesformproperties.cpp

@@ -491,6 +491,11 @@ void QgsAttributesFormProperties::onAttributeSelectionChanged()
       mAttributeTypeDialog->setVisible( false );
       break;
     }
+    case DnDTreeItemData::QmlWidget:
+    {
+
+      break;
+    }
 
   }
 }
@@ -572,6 +577,15 @@ QgsAttributeEditorElement *QgsAttributesFormProperties::createAttributeEditorWid
       widgetDef = container;
       break;
     }
+
+    case DnDTreeItemData::QmlWidget:
+    {
+      QgsAttributeEditorQmlElement *element = new QgsAttributeEditorQmlElement( parent );
+      element->setQmlCode( "ABC " );
+
+      widgetDef = element;
+      break;
+    }
   }
 
   widgetDef->setShowLabel( itemData.showLabel() );

src/core/qgsattributeeditorelement.cpp

@@ -151,6 +151,14 @@ void QgsAttributeEditorRelation::setShowUnlinkButton( bool showUnlinkButton )
   mShowUnlinkButton = showUnlinkButton;
 }
 
+QgsAttributeEditorElement *QgsAttributeEditorQmlElement::clone( QgsAttributeEditorElement *parent ) const
+{
+  QgsAttributeEditorQmlElement *element = new QgsAttributeEditorQmlElement( parent );
+  element->setQmlCode( mQmlCode );
+
+  return element;
+}
+
 QString QgsAttributeEditorQmlElement::qmlCode() const
 {
   return mQmlCode;

src/core/qgsattributeeditorelement.h

@@ -412,6 +412,11 @@ class CORE_EXPORT QgsAttributeEditorRelation : public QgsAttributeEditorElement
     bool mShowUnlinkButton = true;
 };
 
+/**
+ * An attribute editor widget that will represent arbitrary QML code.
+ *
+ * \since QGIS 3.4
+ */
 class CORE_EXPORT QgsAttributeEditorQmlElement : public QgsAttributeEditorElement
 {
   public:
@@ -419,7 +424,20 @@ class CORE_EXPORT QgsAttributeEditorQmlElement : public QgsAttributeEditorElemen
       : QgsAttributeEditorElement( AeTypeQmlElement, "TODO NAME", parent )
     {}
 
+    QgsAttributeEditorElement *clone( QgsAttributeEditorElement *parent ) const override SIP_FACTORY;
+
+    /**
+     * The QML code that will be represented within this widget.
+     *
+     * \since QGIS 3.4
+     */
     QString qmlCode() const;
+
+    /**
+     * The QML code that will be represented within this widget.
+     *
+     * @param qmlCode
+     */
     void setQmlCode( const QString &qmlCode );
 
   private:

src/gui/qgsattributeform.cpp

@@ -1775,6 +1775,10 @@ QgsAttributeForm::WidgetInfo QgsAttributeForm::createWidgetFromDef( const QgsAtt
       const QgsAttributeEditorQmlElement *elementDef = static_cast<const QgsAttributeEditorQmlElement *>( widgetDef );
 
       QgsQmlWidgetWrapper *qmlWrapper = new QgsQmlWidgetWrapper( mLayer, nullptr, this );
+      QTemporaryFile *qmlFile = new QTemporaryFile();
+      qmlFile->write( elementDef->qmlCode().toUtf8() );
+      qmlFile->setParent( qmlWrapper );
+
       qmlWrapper->setConfig( mLayer->editFormConfig().widgetConfig( "TODO NAME??" ) );
       qmlWrapper->setContext( context );