Action

An action variable is the definition of an action that can be used in a workflow

Construction

An action is a structure that contains some configuration information and some code to perform a task within a workflow and takes the following form:

actionname = action in "category"
    // Description
    (in name as type (description)? (optional)?)*
    (out name as type (description)?)*
    exit ("transition")*

    (statement)*
    return "transition"
end

An example of a simple greeting action:

hello_message = action in "general"
    // Greets the passed-in user name
    in user as Scalar
    out message as Scalar
    exit "ok"

    output.message = "Hello " + input.user
    return "ok"
end

Properties

An action has the following properties:

Name	Description	Type
category	A category is used to group similar actions together	Scalar(String)
description	A description of what this action does	Scalar(String)
exits	The exit transitions from this action	List(String)
id	The ID of this action	Scalar(String)
inputs	The input variable args	List(Arg)
outputs	The output variable args	List(Arg)
script	The actual code used to create this action	Scalar(String)
version	The version of this action	Object

Methods

An action has the following methods:

Name	Description	Return Type
run(in, out)	Runs this action and returns the name of the exit transition	Scalar(String)

Example Usage

You can run an action in ODSL code by creating an input object and an output object. The input object should contain the in arguments required by the action and the output object should be empty.

When the action runs, it populates the output object with any output arguments defined.

oi = Object()
oi.user = "World"
oo = Object()
hello_message.run(oi, oo)
print oo

This outputs:

{
  "_id": "oo",
  "_type": "#Object",
  "_links": {},
  "hello_message": {
    "_id": "output",
    "message": "Hello World"
  }
}

Further Reading

• Action service for saving and using actions in the server.