VisualForce - Make Remote Action Call from Static Resource

Remote Action in Visual Force gives us the ability to make a call asynchronously to the salesforce controller and handle the response in a callback function without making the complete page refresh or waiting for an action. Basically in terms of HTML, this can be treated as an ajax call made through the script tags.

Controller

Lets check the controller now and assume that the namespace of the package is 'namespace'.

1. global class ControllerName {
2.    @RemoteAction
3.     global static String MethodName(Paramters....)
4.     {
5.         return 'Hello';
6.     }
7. }

All the remote actions are annotated and static.

Dynamic SOQL for setting fields or relationships

In apex, objects can be created and manipulated dynamically. The only thing that needs to be known is Object Name.

Salesforce maintains a static object called 'Schema'. This will contain information about all the objects in the org in a map format. If the object is a standard object, the key will be just it's name. For custom objects, they are maintained under key as 'NamespacePrefix__'+'Object Name'+'__c'. For example, if the namespace is nspTest and the object name is Tester, then the key will be 'nspTest__Tester__c'. This complete name is called as API name.

Every Object in salesforce is inherited from "sObject" and is related to a schema. The information about the object is called "describe". It includes the fields related to this objects, child relationships like the lookup's master-childs etc.... If the field it custom field, the name will have '__c' suffix.

Schema.SObjectType targetType = Schema.getGlobalDescribe().get(sObjName);
Map fieldMap = targetType.getDescribe().fields.getMap();
Schema.SObjectField sField = fieldMap.get(fieldToUpdate);