Rule your Apex Governor Limits through actionFunction

Recently I ran into an issue where I had to make more than 10 HTTP Callouts from my Apex code. Immediate solution we would think would be batch apex or future calls, but this was not a great idea as user would have to wait till the whole process is complete and also due to the number of apex job limits.

Finally we came up this solution – use actionFunction and split Apex callouts. Since Limit of 10 API Callouts is for single execution, we can always make multiple executes with smaller number of callouts. For example – If originally I had to make 20 callouts on click of a button, What if I click 4 different buttons with 5 Callouts each – We will not hit the Limit here…!

Here is the sample code for the same.

/*
	Controller for Demo Page
*/
public with sharing class DemoPageControler {

	//Declare vars...
	List objAccounts;
	public String currentStatus {get;set;}
	 
	//Constructor
	public DemoPageControler(){
	
		objAccounts = new List();
	}
	
	//main method... 
	public void processRecords(){
		//This method when called will throw exception
		process1();
		process2();
		process3();
		process4();
	}
	
	public void process1(){
	
		//This function makes 5 Callouts
			callHTTP();
			callHTTP();
			callHTTP();
			callHTTP();
			callHTTP();
		
		currentStatus = 'Process 1 completed';
	}
	
	public void process2(){
	
		
		//This function makes 5 Callouts
			callHTTP();
			callHTTP();
			callHTTP();
			callHTTP();
			callHTTP();
		
		currentStatus = 'Process 2 completed';
	}
	
	public void process3(){
	
		//This function makes 5 Callouts
			callHTTP();
			callHTTP();
			callHTTP();
			callHTTP();
			callHTTP();
		
		currentStatus = 'Process 3 completed';
	}
	
	public void process4(){
	
		//This function makes 5 Callouts
			callHTTP();
			callHTTP();
			callHTTP();
			callHTTP();
			callHTTP();
		
		currentStatus = 'Process completed';
	}
	
	public void blankFunction(){
	
	
	}
	
	public void callHTTP() { 
	
		String strurl='http://maps.googleapis.com/maps/api/geocode/xml?address=92618&sensor=false';
        HttpRequest req=new HttpRequest();
        req.setEndpoint(strurl);
        req.setMethod('POST');
        string strbody='hi';
        req.setBody(strbody);
        req.setCompressed(true);
        Http http=new Http();
        HTTPResponse res=http.send(req);
        string strRes=res.getbody();
        system.debug('**** Response XML Data is *****'+strRes);
	
	}
}

VisualForce Page code:

We can use the same process to get around other similar exceptions like too many DML operations, too many script statements.

 

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