qt-everywhere-src-5.14.1/qtscxml/src/scxml/doc/qtscxml-scxml-compliance.qdoc

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/*!
    \page qtscxml-scxml-compliance.html
    \title SCXML Compliance
    \brief Describes the compliance of the Qt SCXML implementation with the
    SCXML specification.

    \section1 Supported Data Models

    Qt SCXML supports the following data models:

    \list
      \li null data model, as described in
        \l {SCXML Specification - B.1 The Null Data Model}
      \li ECMAScript data model, as described in
        \l {SCXML Specification - B.2 The ECMAScript Data Model}
      \li C++ data model, as described in the QScxmlCppDataModel documentation
    \endlist

    \section1 Supported Elements and Attributes

    The Qt SCXML implementation is SCXML compliant, with a few exceptions:

    \list
    \li Event data (\c _event.data) is implemented as a QVariant. If parameters
        are passed to \c <send>, the QVariant holds a QVariantMap, so multiple
        parameters with the same name are not supported.
    \li There is no "raw" representation of an event.
    \li The (optional) basic http event I/O processor is not supported.
    \li The contents of a \c <script> tag and a \c <data> tag must be valid for
        the chosen data model. So, as an example: XML content inside <data> is
        not supported. However, the ECMAScript data model does support data in
        JSON format.
    \li The only service that can be instantiated with \c <invoke> is another
        SCXML state machine.
    \li To keep the behavior of dynamically created state machines and compiled
        state machines the same, the \e typeexpr and \e srcexpr attributes are
        not supported. Moreover, if a \c <content> tag is
        used inside an \c <invoke> tag, that content must be XML. Specifically,
        dynamically creating SCXML, for example by concatenating strings with
        the ECMAScript data model, is not supported.
    \endlist

    \section1 Qt SCXML Extensions

    The Qt SCXML implementation extends SCXML in the following ways:

    \list
    \li If the event is an error event, \c _event.errorMessage will contain a
        more detailed description of the error.
    \endlist
*/