SharePoint 2013: Start Workflow with JavaScript Client Object Model

I have a request to start workflow using client side code. Below is the code that fix my issue:

Code sample:

<button type="button" onclick="Startworkflow(); return false;">Start Workflow</button>

<script src="https://code.jquery.com/jquery-1.7.1.min.js"></script>

<script>

function Startworkflow()

{ LoadScripts(); }

function LoadScripts(){

 SP.SOD.executeFunc("sp.js", "SP.ClientContext" , function(){

  SP.SOD.registerSod('sp.workflowservices.js', SP.Utilities.Utility.getLayoutsPageUrl('sp.workflowservices.js'));

  SP.SOD.executeFunc('sp.workflowservices.js', "SP.WorkflowServices.WorkflowServicesManager", StartWorkflow);

 }) 

}





//Subscription id - Workflow subscription id

//list item id for which to start workflow. If site workflow, then send null for itemId

function StartWorkflow() {

 
   var subscriptionId = "f5fa7d47-52c0-48af-9728-acfad55731d2";

   var itemId = "";



   var ctx = SP.ClientContext.get_current();

   var web = ctx.get_web();

   var wfManager = new SP.WorkflowServices.WorkflowServicesManager(ctx, web);



   var subscription = wfManager.getWorkflowSubscriptionService().getSubscription(subscriptionId);

   ctx.load(subscription, 'PropertyDefinitions');

   ctx.executeQueryAsync(

       function (sender, args) {

           var params= new Object();

           //Find initiation data to be passed to workflow.

           var formData = subscription.get_propertyDefinitions()["FormData"];

           if (formData != null && formData != 'undefined' && formData != "") {

               var assocParams = formData.split(";#");

               for (var i = 0; i < assocParams.length; i++) {

                   params[assocParams[i]] = subscription.get_propertyDefinitions()[assocParams[i]];

               }

           }

           if (itemId) {

               wfManager.getWorkflowInstanceService().startWorkflowOnListItem(subscription, itemId, params);

           }

           else {

               wfManager.getWorkflowInstanceService().startWorkflow(subscription, params);

           }

           ctx.executeQueryAsync(

               function (sender, args) {

                   console.log("workflow start successfully");

               },

               function (sender, args) {
                 
                   alert('Failed to run workflow');

               }

           );

       },

       function (sender, args) {         

           alert('Failed to run workflow');

       }

   );

 }

As I have a site workflow, I am passing "itemId" parameter value null. You can pass your item id there.


Reference: http://ranaictiu-technicalblog.blogspot.in/2013/06/sharepoint-2013-start-workflow-with.html