Action Language (Stateflow)

Stateflow

Keyword Identifiers

Stateflow action language is heavily dependent on action language keywords that identify different types of actions. For an understanding of each keyword, see the following topics:

State Action Type Keywords -- Defines the leading keywords that specify action language categories in states.
Implicit Event Keywords -- Defines the event keywords for events that occur when states are entered or exited or when a data value changes.
Special Function Keywords -- Defines the keywords used to call special functions in action language.

Note Use of these keywords in any way other than their intended meaning within the rules of the notation will cause unpredictable results.

State Action Type Keywords

Each of the following keywords defines a category of action language notation for states. The short form of each keyword uses the characters displayed in bold type.

State Action Language Keyword
Meaning

during
Actions that follow are executed as part of a state's during action.

entry
Actions that follow are executed as part of a state's entry action.

exit
Actions that follow are executed as part of a state's exit action.

on event_name
Actions that follow are executed when the event_name specified as an argument to the on keyword is broadcast.

State Action Language Keyword	Meaning
`during`	Actions that follow are executed as part of a state's `during` action.
`entry`	Actions that follow are executed as part of a state's `entry` action.
`exit`	Actions that follow are executed as part of a state's `exit` action.
`on` `event_name`	Actions that follow are executed when the `event_name` specified as an argument to the `on` keyword is broadcast.

Implicit Event Keywords

Each of the following keywords generates implicit events in the action language notation for states and transitions (see Implicit Events). The short form of each keyword uses the characters displayed in bold type.

State Action Language Keyword
Meaning

change(data_name)
Specifies and implicitly generates a local event when the value of data_name changes.

enter(state_name)
Specifies and implicitly generates a local event when the specified state_name is entered.

exit(state_name)
Specifies and implicitly generates a local event when the specified state_name is exited.

tick
Same as wakeup keyword.

wakeup
Specifies and implicitly generates a local event when the chart of the action being evaluated awakens.

State Action Language Keyword	Meaning
`change(data_name)`	Specifies and implicitly generates a local event when the value of `data_name` changes.
`en`ter(`state_name`)	Specifies and implicitly generates a local event when the specified `state_name` is entered.
`exit`(`state_name`)	Specifies and implicitly generates a local event when the specified `state_name` is exited.
`tick`	Same as `wakeup` keyword.
`wakeup`	Specifies and implicitly generates a local event when the chart of the action being evaluated awakens.

Special Function Keywords

Each of the keywords listed below call special functions in the action language notation for states and transitions.

Special Function Keyword
Meaning

in(state_name)
A condition function that is evaluated as true when the state_name specified as the argument is active.

ml(evalString,arg1,arg2,...)
Action specifies a call using ml function notation. See ml Function.

ml.MATLAB_workspace_data
Action specifies a call using the ml name space notation. See ml Namespace Operator.

send(event_name,state_name)
Send the event_name specified to the state_name specified (directed event broadcasting). See Directed Event Broadcasting.

Special Function Keyword	Meaning
`in(state_name)`	A condition function that is evaluated as true when the `state_name` specified as the argument is active.
`ml(evalString,arg1,arg2,...)`	Action specifies a call using `ml` function notation. See ml Function.
`ml.MATLAB_workspace_data`	Action specifies a call using the `ml` name space notation. See ml Namespace Operator.
`send(event_name,state_name)`	Send the `event_name` specified to the `state_name` specified (directed event broadcasting). See Directed Event Broadcasting.

Types of Action Language Operations