Streaming API example in Salesforce

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Streaming API example in Salesforce

Magulan Duraipandian

1. Go to User Interface.

2. Enable “Streaming API”.

3. Check whether your profile has API Enabled permission.

4. Go to this site and download the file – http://download.cometd.org/cometd-2.2.0-distribution.tar.gz

5. Extract the downloaded file.

6. Open Command Prompt and execute the below commands;

cd cometd-2.2.0/cometd-javascript/common/target

jar xvf cometd-javascript-common-2.2.0.war org/cometd.js

Note:

In command Prompt, make sure you navigate to the drive where it has been extracted.

7. Go to D:cometd-2.2.0cometd-javascriptcommontargetorg path. You will be able to find cometd.js file.

8. Go to D:cometd-2.2.0cometd-javascriptjquerysrcmainwebappjquery path. In my case I extracted the file to D drive. You will be able to see the files as below:

9. Go Static Resources and create new Static Resources as below in Salesforce

File Name         Static Resource Name
cometd.js                    cometd
jquery-1.5.1.js             jquery
json2.js                     json2
jquery.cometd.js     jquery_cometd

10. Code for Visualforce and Apex.

Visualforce Page:

<apex:page controller="StreamingAPIController">
    <apex:includeScript value="{!$Resource.cometd}"/>
    <apex:includeScript value="{!$Resource.jquery}"/>
    <apex:includeScript value="{!$Resource.json2}"/>
    <apex:includeScript value="{!$Resource.jquery_cometd}"/>
    <script type="text/javascript">
    (function($){
        $(document).ready(function() {
            // Connect to the CometD endpoint
            $.cometd.init({
               url: window.location.protocol+'//'+window.location.hostname+'/cometd/24.0/',
               requestHeaders: { Authorization: 'OAuth {!$Api.Session_ID}'}
           });

           // Subscribe to a topic. JSON-encoded update will be returned
           // in the callback
           $.cometd.subscribe('/topic/AccountUpdates', function(message) {
               callRefresh();
            });
        });
   })(jQuery)
   function disconnect() {
       $.cometd.disconnect();
   }
   window.onbeforeunload = disconnect;
   </script>
   <apex:form >
   <apex:actionFunction name="callRefresh" action="{!refresh}"/>
   
<apex:pageBlock >
   
    <apex:pageBlockTable value="{!listAccount}" var="a">
   
        <apex:column value="{!a.Name}"/>
   
        <apex:column value="{!a.AccountNumber}"/>
   
    </apex:pageBlockTable>
   
</apex:pageBlock>
   
</apex:form>
</apex:page>

Apex Controller:

public class StreamingAPIController {        
    public StreamingAPIController() {
    }
    
    public List<Account> getlistAccount() {
        return [SELECT Id, Name, AccountNumber FROM Account WHERE Active__c = true];
    }
    
    public PageReference refresh() {
        getlistAccount();
        return null;
    }
}

11. Create a PushTopic using the below code in Developer Console.

PushTopic pushTopic = new PushTopic();
pushTopic.Name = 'AccountUpdates';
pushTopic.Query = 'SELECT Id, Name, AccountNumber FROM Account WHERE Active__c = true';
pushTopic.ApiVersion = 36.0;
pushTopic.NotifyForOperationCreate = true;
pushTopic.NotifyForOperationUpdate = true;
pushTopic.NotifyForOperationUndelete = true;
pushTopic.NotifyForOperationDelete = true;
pushTopic.NotifyForFields = 'Referenced';
insert pushTopic;

12. To test it, open the visualforce page. Open Accounts tab and create a new account with Active check box true. If you go back to the Visualforce page, the account created will be displayed there.

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