Calling a Server-Side Action

1swfobject.registerObject("clippy.codeblock-0", "9");{
2    "echo" : function(component) {
3        // create a one-time use instance of the serverEcho action
4        // in the server-side controller
5        var a = component.get("c.serverEcho");
6        a.setParams({ firstName : component.get("v.firstName") });
7
8        // Create a callback that is executed after 
9        // the server-side action returns
10        a.setCallback(this, function(action) {
11            if (action.getState() === "SUCCESS") {
12                // Alert the user with the value returned 
13                // from the server
14                alert("From server: " + action.getReturnValue());
15
16                // You would typically fire a event here to trigger 
17                // client-side notification that the server-side 
18                // action is complete
19            }
20            else if (action.getState() === "ERROR"){
21                var errors = a.getError();
22                if (errors) {
23                    $A.logf("Errors", errors);
24                    if (errors[0] && errors[0].message) {
25                        $A.error("Error message: " + 
26                                 errors[0].message);
27                    }
28                } else {
29                    $A.error("Unknown error");
30                }
31            }
32            else {
33                alert("Action state: " + action.getState());
34            }
35        });
36
37        // A client-side action could cause multiple events, 
38        // which could trigger other events and 
39        // other server-side action calls.
40        // $A.enqueueAction adds the server-side action to the queue.
41        $A.enqueueAction(a);
42    }
43}