Use Of AJAX Toolkit ( Connection.js) in Salesforce How and when to use it

Hi, in this post i will explain you about Ajax Toolkit in salesforce. How and when to use Ajax toolkit.

So This post is divided into three section :

1.  Ajax toolkit Explaination(Defination)
2.  When to use ajax toolkit
3.  Ajax toolkit Example

1. What is AJAX Toolkit 

Ajax Toolkit  is a JavaScript wrapper around the API .  Ajax Toolkit Embed API calls and processes, such as within a Visualforce page, or custom button .Salesforce offer AJAX tool kit to run javascript and allowing user to make a connection with Salesforce and query salesforce from javascript, the data in-return can be handled in own fashion to be displayed on the page.

2 . When to use AJAX Toolkit

• AJAX Toolkit is used when you need to  working with small amounts of data.
• Display or modify a single record.
• Display two or three fields from many records
• Perform one or more simple calculations, then update a record.

3. Ajax toolkit Example

Requirement :  On click of custom button in contact details page  call a controller function and then perform some operation on the object by using  connection.js .

So to fulfill this requirement we follow the below steps :

1.  Create a custom button . And add this custom button  to contact layout  follow the steps in the  image to create a custom button .

2. Write an apex class  and the function that we call using sforce.apex.execute method on button click

here is the apex class example code.

global class StopOtherContacts {
webservice static string updateContact(String contactid)
{
contact thiscontact = [select id,Client__c,accountid from contact where id =: contactid];
list<contact> contacts;
//if(thisContact != null && thiscontact.accountid != null && thiscontact.Client__c != null)
contacts = [select id, Lead_Status__c, Client__c from contact  where Client__c =: thisContact.Client__c and accountid =: thiscontact.accountid and id!=:thiscontact.id];
if(contacts != null)
{
for(contact contact:contacts){
contact.Lead_Status__c = 'Not The DM';
}
update contacts;
}
if(contacts != null)
return 'True';
else 
return 'False';
}
}

3. Now Call this class on button click  by the help of sforce.execute method . write the below code snippet on javascript  portion in your custom button .

{!REQUIRESCRIPT("/soap/ajax/29.0/connection.js")}
{!REQUIRESCRIPT("/soap/ajax/29.0/apex.js")}
var cnnId='{!Contact.Id}'

var result = sforce.apex.execute("StopOtherContacts","updateContact",{contactid:cnnId});

if ( result == 'True'){
txt="Contacts Updated Successfully.\n\n"; 
txt+="Click OK to continue.\n\n"; 
alert(txt); 
} else {
txt="There was an error on this page.\n\n"; 
txt+="Click OK to continue.\n\n"; 
alert(txt); 
}
//sforce.debug.trace=true;


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