Qt SCXML Invoke Example (Static)

Invokes a compiled nested state machine.

../_images/invoke-static.png

Invoke Example (Static) demonstrates how to use the <invoke> element with generated nested state-machines, where the SCXML file is compiled to a C++ class. The <invoke> element is used to create an instance of an external service.

Running the Example

To run the example from Qt Creator , open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.

Invoking the State Machine

In statemachine.scxml, we specify a state machine with the name Directions of type http://www.w3.org/TR/scxml/ to invoke:

Compiling the State Machine

We link against the Qt SCXML module by adding the following lines to the example’s build files.

  • invoke-static.pro*

when using qmake:

We then specify the state machine to compile:

  • CMakeLists.txt*

when using cmake:

We then specify the state machine to compile:

The statechart directives STATECHARTS or qt6_add_statecharts invoke the Qt SCXML Compiler, qscxmlc, which is run automatically to generate statemachine.h and statemachine.cpp, which are then added appropriately as headers and sources for compilation.

Instantiating the State Machine

We instantiate the generated Directions class in the invoke-static.cpp file, as follows:

Example project @ code.qt.io