/****************************************************************************
**
** This file is part of Qt Installer Framework
**
** Copyright (c) 2012 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact: Nokia Corporation (qt-info@nokia.com)
**
**
** GNU Free Documentation License
**
** Alternatively, this file may be used under the terms of the GNU Free
** Documentation License version 1.3 as published by the Free Software
** Foundation and appearing in the file included in the packaging of this
** file.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
****************************************************************************/

/*!
    \contentspage{index.html}{Qt Installer Framework}
    \previouspage noninteractive.html
    \page scripting.html
    \nextpage operations.html

    \title Component Scripting

    For each component, you can specify one script that is loaded and run by the
    installer. The script format has to be compatible with QScriptEngine.

    \section1 Construction

    The script has to contain a \c Component object that the installer creates
    when it loads the script. Therefore, the script must contain at
    least the \a Component() function, which performs initialization, such as
    putting pages in the correct places or connecting signals and slots.

    The following code snippet places the \a ErrorPage (which is the class
    name of the user interface file loaded from errorpage.ui) in front of the
    ready for installation page and sets its completeness to \c false.

    \code
    function Component()
    {
        // Add a user interface file called ErrorPage, which should not be complete
        installer.addWizardPage( component, "ErrorPage", QInstaller.ReadyForInstallation );
        component.userInterface( "ErrorPage" ).complete = false;
    }
    \endcode

    For more information, see the documentation for \a addWizardPage and
    \a userInterface.

    \section1 Installer Hooks

    You can add the following hook methods into your script:

    \table
        \header
            \o  Method
            \o  Description
        \row
            \o  \a{Component.prototype.retranslateUi}
            \o  Called when the language of the installer changes.
        \row
            \o  \a{Component.prototype.createOperations}
            \o  See \a QInstaller::Component::createOperations.
        \row
            \o  \a{Component.prototype.createOperationsForArchive}
            \o  See \a QInstaller::Component::createOperationsForArchive.
        \row
            \o  \a{Component.prototype.createOperationsForPath}
            \o  See \a QInstaller::Component::createOperationsForPath.
    \endtable

    \section1 Global Variables

    The installer puts the following symbols into the script space:

    \table
        \header
            \o  Symbol
            \o  Description
        \row
            \o  installer
            \o  Reference to the \a installer of the component
        \row
            \o  component
            \o  Reference to the \a Component of the component
    \endtable

    All methods marked with \a Q_INVOKABLE as well as all signals, slots, and
    properties can be used by the script.

    \section1 Message Boxes

    You can show a \a QMessageBox from within the script by using:

    \code
    QMessageBox.critical
    QMessageBox.information
    QMessageBox.question
    QMessageBox.warning
    \endcode

    For your convenience, the values for \a QMessageBox::StandardButton are made
    available by using \a QMessageBox.Ok, \a QMessageBox.Open, and so on.

    \section1 Adding Operations to Components

    You might want to add custom operations after extracting the content, when
    copying files or patching file content, for example. You can create and add
    update operations to the installation from within
    a script using \a QInstaller::Component::addOperation.

    Each operation has a unique key used for identification and can take up to
    five parameters. In the parameter values, you can use variables as set in
    \a QInstaller::Installer::setValue. For more information, see
    \l{Predefined Variables}.

    For a summary of all available operations, see \l{Operations}.

    \section1 Registering Custom Operations

    You can register custom installation operations in the installer by deriving
    \a KDUpdater::UpdateOperation. The following code displays the methods that
    you must implement:

  \code
  #include <KDUpdater/UpdateOperation>

  class CustomOperation : public KDUpdater::UpdateOperation
  {
  public:
    CustomOperation()
    {
        setName( "CustomOperation" );
    }

    void backup()
    {
        // do whatever is needed to restore the state in undoOperation()
    }

    bool performOperation()
    {
        const QStringList args = arguments();
        // do whatever is needed to do for the given arguments

        bool success = ...;
        return success;
    }

    void undoOperation()
    {
        // restore the previous state, as saved in backup()
    }

    bool testOperation()
    {
        // currently unused
        return true;
    }

    CustomOperation* clone() const
    {
        return new CustomOperation;
    }

    QDomDocument toXml()
    {
        // automatically adds the operation's arguments and everything set via setValue
        QDomDocument doc = KDUpdater::UpdateOperation::toXml();

        // if you need any information to undo the operation you did,
        // add them to the doc here

        return doc;
    }

    bool fromXml( const QDomDocument& doc )
    {
        // automatically loads the operation's arguments and everything set via setValue
        if( !KDUpdater::UpdateOperation::fromXml( doc ) )
            return false;

        // if you need any information to undo the operation you did,
        // read them from the doc here

        return true;
    }
  };
  \endcode

    Finally, you need to register your custom operation class, as follows:
  \code
  #include <KDupdater/UpdateOperationFactory>

  KDUpdater::UpdateOperationFactory::instance().registerUpdateOperation< CustomOperation >( "CustomOperation" );
  \endcode

    Now you can use your operation in the installer in the same way as the
    predefined operations.

  \section1 Predefined Variables

    You can use the following predefined variables in scripts to facilitate
    directory access:

    \table
        \header
            \o  Symbol
            \o  Description
        \row
            \o  ProductName
            \o  Name of the product to be installed, as defined in config.xml.
        \row
            \o  ProductVersion
            \o  Version number of the product to be installed, as defined in
                config.xml.
        \row
            \o  Title
            \o  Title of the installation program, as defined in config.xml.
        \row
            \o  Publisher
            \o  Publisher of the installation program, as defined in config.xml.
        \row
            \o  Url
            \o  Product URL, as defined in config.xml.
        \row
            \o  StartMenuDir
            \o  Start menu group, as defined in config.xml. Available on
                Windows, only.
        \row
            \o  TargetDir
            \o  Target directory for installation, as selected by the user.
        \row
            \o  DesktopDir
            \o  Name of the directory that contains the user's desktop.
        \row
            \o  os
            \o  Current platform: \c "x11", \c "win", or \c "mac".
    \endtable

    \note You can use the variables in the parameter list for installation
    operations. For example, \c{"{TargetDir}/settings.xml"} might be expanded
    to: \c{"C:/Program Files/My Program/settings.xml"}.
*/