Consolidate duplicated QQmlExtensionPlugin documentation.

There have already been doc improvements made to one of the duplicated
pieces and not the other. This patch uses the improved one.

Change-Id: I12a6cb013e61f63e67fb9d691ee58ba12e21054d
Reviewed-by: Venugopal Shivashankar <venugopal.shivashankar@digia.com>

3 files changed, 85 insertions, 149 deletions

diff --git a/src/qml/doc/src/qmllanguageref/modules/cppplugins.qdoc b/src/qml/doc/src/qmllanguageref/modules/cppplugins.qdoc
index 90e432a8ef..a2397b6cfb 100644
--- a/src/qml/doc/src/qmllanguageref/modules/cppplugins.qdoc
+++ b/src/qml/doc/src/qmllanguageref/modules/cppplugins.qdoc
@@ -38,90 +38,7 @@
     A module requires at least one type registered in order to be considered
     valid.
 
-    QQmlExtensionPlugin is a plugin interface that makes it possible to
-    create QML extensions that can be loaded dynamically into QML applications.
-    These extensions allow custom QML types to be made available to the
-    QML engine.
-
-    To write a QML extension plugin:
-    \list 1
-    \li Subclass QQmlExtensionPlugin
-        \list
-            \li Use the Q_PLUGIN_METADATA() macro to register the plugin with
-                the Qt meta object system
-            \li Override the \l{QQmlExtensionPlugin::}{registerTypes()} method
-                and call qmlRegisterType() to register the types to be exported
-                by the plugin
-        \endlist
-    \li Write a project file for the plugin
-    \li Create a \l{Module Definition qmldir Files}{qmldir file} to
-        describe the plugin
-    \endlist
-
-    QML extension plugins are for either application-specific or library-like
-    plugins. Library plugins should limit themselves to registering types, as
-    any manipulation of the engine's root context may cause conflicts or other
-    issues in the library user's code.
-
-\section1 Plugin Example
-
-    Suppose there is a new \c TimeModel C++ class that should be made available
-    as a new QML type. It provides the current time through \c hour and \c minute
-    properties.
-
-    \snippet qmlextensionplugins/plugin.cpp 0
-    \dots
-
-    To make this type available, we create a plugin class named \c QExampleQmlPlugin
-    which is a subclass of \l QQmlExtensionPlugin. It overrides the
-    \l{QQmlExtensionPlugin::}{registerTypes()} method in order to register the \c TimeModel
-    type using qmlRegisterType(). It also uses the Q_PLUGIN_METADATA() macro in the class
-    definition to register the plugin with the Qt meta object system using a unique
-    identifier for the plugin.
-
-    \snippet qmlextensionplugins/plugin.cpp plugin
-
-    The \c TimeModel class receives a \c{1.0} version of this plugin library, as
-    a QML type called \c Time. The Q_ASSERT() macro can ensure the type namespace is
-    imported correctly by any QML components that use this plugin. The
-    \l{Defining QML Types from C++} article has more information about registering C++
-    types into the runtime.
-
-    For this example, the TimeExample source directory is in
-    \c{imports/TimeExample}.  The plugin's type namespace will mirror
-    this structure, so the types are registered into the namespace
-    "TimeExample".
-
-    Additionally, the project file, in a \c .pro file, defines the project as a plugin library,
-    specifies it should be built into the \c imports/TimeExample directory, and registers
-    the plugin target name and various other details:
-
-    \code
-    TEMPLATE = lib
-    CONFIG += qt plugin
-    QT += qml
-
-    DESTDIR = imports/TimeExample
-    TARGET = qmlqtimeexampleplugin
-    SOURCES += qexampleqmlplugin.cpp
-    \endcode
-
-    Finally, a \l{Module Definition qmldir Files}{qmldir file} is required
-    in the \c imports/TimeExample directory to describe the plugin and the types that it
-    exports. The plugin includes a \c Clock.qml file along with the \c qmlqtimeexampleplugin
-    that is built by the project (as shown above in the \c .pro file) so both of these
-    need to be specified in the \c qmldir file:
-
-    \quotefile qmlextensionplugins/imports/TimeExample/qmldir
-
-    Once the project is built and installed, the new \c Time component is
-    accessible by any QML component that imports the \c TimeExample
-    module
-
-    \snippet qmlextensionplugins/plugins.qml 0
-
-    The full source code is available in the \l {qmlextensionplugins}{plugins example}.
-
+    \include qqmlextensionplugin.qdocinc
 
 \section1 Reference
 
diff --git a/src/qml/doc/src/qmllanguageref/modules/qqmlextensionplugin.qdocinc b/src/qml/doc/src/qmllanguageref/modules/qqmlextensionplugin.qdocinc
new file mode 100644
index 0000000000..9bb863a90b
--- /dev/null
+++ b/src/qml/doc/src/qmllanguageref/modules/qqmlextensionplugin.qdocinc
@@ -0,0 +1,83 @@
+QQmlExtensionPlugin is a plugin interface that makes it possible to
+create QML extensions that can be loaded dynamically into QML applications.
+These extensions allow custom QML types to be made available to the
+QML engine.
+
+To write a QML extension plugin:
+\list 1
+\li Subclass QQmlExtensionPlugin
+    \list
+        \li Use the Q_PLUGIN_METADATA() macro to register the plugin with
+            the Qt meta object system
+        \li Override the \l{QQmlExtensionPlugin::}{registerTypes()} method
+            and call qmlRegisterType() to register the types to be exported
+            by the plugin
+    \endlist
+\li Write a project file for the plugin
+\li Create a \l{Module Definition qmldir Files}{qmldir file} to
+    describe the plugin
+\endlist
+
+QML extension plugins are for either application-specific or library-like
+plugins. Library plugins should limit themselves to registering types, as
+any manipulation of the engine's root context may cause conflicts or other
+issues in the library user's code.
+
+\section1 Plugin Example
+
+Suppose there is a new \c TimeModel C++ class that should be made available
+as a new QML type. It provides the current time through \c hour and \c minute
+properties.
+
+\snippet qmlextensionplugins/plugin.cpp 0
+\dots
+
+To make this type available, we create a plugin class named \c QExampleQmlPlugin
+which is a subclass of \l QQmlExtensionPlugin. It overrides the
+\l{QQmlExtensionPlugin::}{registerTypes()} method in order to register the \c TimeModel
+type using qmlRegisterType(). It also uses the Q_PLUGIN_METADATA() macro in the class
+definition to register the plugin with the Qt meta object system using a unique
+identifier for the plugin.
+
+\snippet qmlextensionplugins/plugin.cpp plugin
+
+The \c TimeModel class receives a \c{1.0} version of this plugin library, as
+a QML type called \c Time. The Q_ASSERT() macro can ensure the type namespace is
+imported correctly by any QML components that use this plugin. The
+\l{Defining QML Types from C++} article has more information about registering C++
+types into the runtime.
+
+For this example, the TimeExample source directory is in
+\c{imports/TimeExample}.  The plugin's type namespace will mirror
+this structure, so the types are registered into the namespace
+"TimeExample".
+
+Additionally, the project file, in a \c .pro file, defines the project as a plugin library,
+specifies it should be built into the \c imports/TimeExample directory, and registers
+the plugin target name and various other details:
+
+\code
+TEMPLATE = lib
+CONFIG += qt plugin
+QT += qml
+
+DESTDIR = imports/TimeExample
+TARGET = qmlqtimeexampleplugin
+SOURCES += qexampleqmlplugin.cpp
+\endcode
+
+Finally, a \l{Module Definition qmldir Files}{qmldir file} is required
+in the \c imports/TimeExample directory to describe the plugin and the types that it
+exports. The plugin includes a \c Clock.qml file along with the \c qmlqtimeexampleplugin
+that is built by the project (as shown above in the \c .pro file) so both of these
+need to be specified in the \c qmldir file:
+
+\quotefile qmlextensionplugins/imports/TimeExample/qmldir
+
+Once the project is built and installed, the new \c Time component is
+accessible by any QML component that imports the \c TimeExample
+module
+
+\snippet qmlextensionplugins/plugins.qml 0
+
+The full source code is available in the \l {qmlextensionplugins}{plugins example}.
diff --git a/src/qml/qml/qqmlextensionplugin.cpp b/src/qml/qml/qqmlextensionplugin.cpp
index 7b560268ba..d86fbc5999 100644
--- a/src/qml/qml/qqmlextensionplugin.cpp
+++ b/src/qml/qml/qqmlextensionplugin.cpp
@@ -44,71 +44,7 @@ QT_BEGIN_NAMESPACE
 
     \ingroup plugins
 
-    QQmlExtensionPlugin is a plugin interface that makes it possible to
-    create QML extensions that can be loaded dynamically into QML applications.
-    These extensions allow custom QML types to be made available to the QML engine.
-
-    To write a QML extension plugin:
-
-    \list
-    \li Subclass QQmlExtensionPlugin, implement registerTypes() method to register types
-    using qmlRegisterType(), and export the class using the Q_PLUGIN_METADATA() macro
-    \li Write an appropriate project file for the plugin
-    \li Create a \l{Module Definition qmldir Files}{qmldir file} to describe the plugin
-    \endlist
-
-    QML extension plugins can be used to provide either application-specific or
-    library-like plugins. Library plugins should limit themselves to registering types,
-    as any manipulation of the engine's root context may cause conflicts
-    or other issues in the library user's code.
-
-
-    \section1 An Example
-
-    Suppose there is a new \c TimeModel C++ class that should be made available
-    as a new QML element. It provides the current time through \c hour and \c minute
-    properties, like this:
-
-    \snippet qmlextensionplugins/plugin.cpp 0
-    \dots
-
-    To make this class available as a QML type, create a plugin that registers
-    this type with a specific \l {QML Modules}{module} using qmlRegisterType(). For this example the plugin
-    module will be named \c TimeExample (as defined in the project
-    file further below).
-
-    \snippet qmlextensionplugins/plugin.cpp plugin
-
-    This registers the \c TimeModel class with the 1.0 version of this
-    plugin library, as a QML type called \c Time. The Q_ASSERT statement
-    ensures the module is imported correctly by any QML components that use this plugin.
-
-    The project file defines the project as a plugin library and specifies
-    it should be built into the \c imports/TimeExample directory:
-
-    \code
-    TEMPLATE = lib
-    CONFIG += qt plugin
-    QT += qml
-
-    DESTDIR = imports/TimeExample
-    TARGET = qmlqtimeexampleplugin
-    ...
-    \endcode
-
-    Finally, a \l{Module Definition qmldir Files}{qmldir file} is required in the \c imports/TimeExample directory
-    that describes the plugin. This directory includes a \c Clock.qml file that
-    should be bundled with the plugin, so it needs to be specified in the \c qmldir
-    file:
-
-    \quotefile qmlextensionplugins/imports/TimeExample/qmldir
-
-    Once the project is built and installed, the new \c Time element can be
-    used by any QML component that imports the \c TimeExample module:
-
-    \snippet qmlextensionplugins/plugins.qml 0
-
-    The full source code is available in the \l {qmlextensionplugins}{plugins example}.
+    \include qqmlextensionplugin.qdocinc
 
     The \l {Writing QML Extensions with C++} tutorial also contains a chapter
     on creating QML plugins.