Aura Component Continuations Example

Here’s the markup for a component with a button that starts the process of calling a continuation.

The component is wired to the Apex class that uses a continuation by setting the controller attribute in the <aura:component> tag.

1<aura:component controller="SampleContinuationClass">
2    <lightning:button label="Call Continuation" onclick="{!c.callContinuation}"/>
3</aura:component>

Here’s the component’s JavaScript controller. The code calls the startRequest Apex method that uses a Continuation object. The response.getReturnValue() value for a successful response in the JavScript controller corresponds to the value returned by the Apex callback method defined in the Continuation object.

1({
2    callContinuation : function(cmp) {
3        var action = cmp.get("c.startRequest");
4        action.setCallback(this, function(response) {
5            var state = response.getState();
6            if (state === "SUCCESS") {
7                console.log("From server: "
8                  + response.getReturnValue()
9                  + '\n' + JSON.stringify(response.getReturnValue()));
10            }
11            else if (state === "INCOMPLETE") {
12                alert("Continuation action is INCOMPLETE");
13            }
14            else if (state === "ERROR") {
15                var errors = response.getError();
16                if (errors) {
17                    if (errors[0] && errors[0].message) {
18                        console.log("Error message: " +
19                                 errors[0].message);
20                    }
21                } else {
22                    console.log("Unknown error");
23                }
24            }
25        });
26        // Enqueue action that returns a continuation
27        $A.enqueueAction(action);
28    }
29})

This JavaScript controller code is similar to any other component that calls an Apex method.

Lightning Aura Components Developer Guide

Aura Component Continuations Example

See Also