- Qt 5.15
- Qt SCXML
- Using the Qt SCXML Compiler (qscxmlc)
- Qt 5.15.16 Reference Documentation

# Using the Qt SCXML Compiler (qscxmlc)

The `qscxmlc` tool reads an .scxml file and produces C++ source and header files, containing a class that implements a state machine as defined in SCXML.

## Usage

The `qscxml` tool is invoked automatically if the QT variable in the project file includes `scxml`, and the .scxml file to use is specified using the `STATECHARTS` variable.

     QT += scxml
     STATECHARTS = MyStatemachine.scxml

With above definitions, `qmake` invokes `qscxmlc` to generate MyStatemachine.h and MyStatemachine.cpp, and adds them to HEADERS and SOURCES variables.

By default, the name of the generated class that implements the state machine corresponds with the name attribute of the `<scxml>` root element.

## Command-Line Options

The `qscxmlc` tool supports the following command-line options, which can be specified using the `QSCXMLC_ARGUMENTS` variable in the project file:

Option | Description
--- | ---
`--namespace <namespace>` | Put the generated class(es) in the specified namespace. You can use the `QSCXMLC_NAMESPACE` variable to specify this in your project file.
`-o <base/out/name>` | The base name of the output files. This can include a path. If none is specified, the basename of the input file is used.
`--header <header/out>` | The name of the output header file. If none is specified, .h is added to the base name.
`--impl <cpp/out>` | The name of the output header file. If none is specified, .cpp is added to the base name.
`--classname <StateMachineClassName>` | The class name of the generated state machine. If none is specified, the value of the name attribute of the <scxml> tag is taken. If that attribute is not specified either, the basename (excluding path) is taken from the input file name.
`--statemethods` | Generate extra accessor and signal methods for states. This way you can connect to state changes with plain QObject::connect() and directly call a method to find out if a state is currently active.