WorkflowJS

WorkflowsJS, built for complex JavaScript applications.

WorkflowJS was inspired by Windows Workflow Foundation (WF) in .NET 4. WorkflowJS allows you to chain smaller Activities together into a larger Workflow.

This library is experimental and development on it has been abandoned. It is unit tested and should contain no bugs.

Building your first Activity

TypeScript example:

/*
 * AddActivity Adds inputs number1 and number2 and sets output total.
 */
class AddActivity implements wfjs.IActivity
{
    public $inputs = ['number1', 'number2'];
    public $outputs = ['total'];

    public Execute(context: wfjs.ActivityContext): void
    {
        var number1: number = parseFloat(context.Inputs['number1']) || 0;
        var number2: number = parseFloat(context.Inputs['number2']) || 0;

        context.Outputs['total'] = number1 + number2;
    }
}

JavaScript example:

/*
 * AddActivity Adds inputs number1 and number2 and sets output total.
 */
function AddActivity()
{
    this.$inputs = ['number1', 'number2'];
    this.$outputs = ['total'];
}

AddActivity.prototype.Execute = function (context)
{
    var number1 = parseFloat(context.Inputs['number1']) || 0;
    var number2 = parseFloat(context.Inputs['number2']) || 0;

    context.Outputs['total'] = number1 + number2;
};

Building your first Workflow

This workflow takes two numbers, adds them together and then multiplies the result by two.

var workflow = wfjs.Flowchart
({
    $inputs: ['number1', 'number2'],
    $outputs: ['total'],
    activities:
    {

        // Add number1 and number2
        'AddNumbers': wfjs.Activity
        ({
            activity: new AddActivity(),
            $inputs:
            {
                'number1': 'this.number1',
                'number2': 'this.number2'
            }
            $outputs:
            {
                'total': 'total'
            },
            next: 'MultiplyByTwo'
        }),

        // Multiply the total by 2
        'MultiplyByTwo': wfjs.Assign
        ({
            values:
            {
                'total': 'this.total * 2'
            }
        })
    }
});

// Invoke the workflow
wfjs.WorkflowInvoker
    .CreateActivity(workflow)
    .Inputs(
    {
        'number1': 123,
        'number2': 456,
    })
    .Invoke((err, ctx) =>
    {
        console.log('Total: ' + ctx.Outputs['total']);
    });

Setting the Input values

Values are evaulated upon runtime making it is possible to make dynamic variable assignments.

Also note, if you want to assign a static string you must use quotes inside the string. Numbers do not require quotes.

$inputs:
{
    'fullName': 'this.firstName = " " + this.lastName',
    'userType': '"web user"'
    'age': 38
}

Pausing and Resuming the Workflow

This is an example of a flowcharts activities that uses Pause.

var workflow = wfjs.Flowchart
({
    activities:
    {

        // Create a random math problem
        'CreateMathProblem': wfjs.Activity
        ({
            activity: new CreateMathActivity(),
            $outputs: {
                'problem': 'problem',
                'solution': 'solution'
            },
            next: 'WaitForAnswer'
        }),

        // Pause the workflow
        'WaitForAnswer': wfjs.Pause
        ({
            next: 'ValidateAnswer'
        }),

        // Resume and validate the answer
        'ValidateAnswer': wfjs.Assign
        ({
            values:
            {
                'correct': 'this.solution == this.answer'
            }
        })
    }
});

Invoke the workflow and save the StateData

wfjs.WorkflowInvoker
    .CreateActivity(activity)
    .Invoke((err, ctx) =>
    {
        if (ctx.State == wfjs.WorkflowState.Paused)
        {
            // save the StateData somewhere
            var stateData = ctx.StateData;
        }
    });

Resume the workflow by setting the State of the workflow.

wfjs.WorkflowInvoker
    .CreateActivity(activity)
    .Inputs(
    {
        'answer': 42
    })
    .State(stateData)
    .Invoke((err, ctx) =>
    {
        var correct = ctx.Outputs['correct'];
    });

Workflow Activity Types

wfjs.Activity

The wfjs.Activity is a basic Workflow Activity

input description

---

activity activity of type IActivity to execute $inputs (optional) activity input mapping $outputs (optional) activity output mapping next (optional) next activity to execute

wfjs.Activity(
{
    activity: IActivity;
    $inputs?: Dictionary<any>;
    $outputs?: Dictionary<string>;
    next?: string;
})

wfjs.Assign

The wfjs.Assign activity is a simple assignment activity.

input description

---

values dictionary of values to set. next (optional) next activity to execute

wfjs.Assign(
{
    values: Dictionary<any>;
    next?: string;
})

wfjs.Decision

The wfjs.Decision tests a condition and goes next to either the true value or false value.

input description

---

condition condition to evaluate to true or false true next activity to execute if condition is true false next activity to execute if condition is false

wfjs.Decision(
{
    condition: string;
    true: string;
    false: string;
})

wfjs.Execute

The wfjs.Execute activity is a quick way to execute a code snippet.

input description

---

execute code to execute next (optional) next activity to execute

wfjs.Execute(
{
    execute: (context: ActivityContext, done?: (err?: Error) => void) => void;
    next?: string;
})

wfjs.Flowchart

The wfjs.Flowchart activity is what you use to tie it all together.

input description

---

$inputs (optional) activity input mapping $outputs (optional) activity output mapping activities Collection of activities to execute

wfjs.Flowchart(
{
    $inputs?: string[];
    $output?: string[];
    activities: wfjs.Dictionary<IActivityBase>;
})