Getting Context in Your Canvas App

When you authenticate your canvas app using signed request, you get the CanvasRequest object (which contains the Context object) as part of the POST to the canvas app URL. If you’re authenicating using OAuth, or you want to make a call to get context information, you can do so by making a JavaScript call.

The following code sample is an example of a JavaScript call to get context. This code creates a link with the text “Get Context” which then calls the Sfdc.canvas.client.ctx function.

1<script>
2    function callback(msg) {
3       if (msg.status !== 200) {
4          alert("Error: " + msg.status);
5          return;
6       }
7       alert("Payload: ", msg.payload);
8    }
9                
10    var ctxlink = Sfdc.canvas.byId("ctxlink");
11    var client = Sfdc.canvas.oauth.client();
12    ctxlink.onclick=function() {
13       Sfdc.canvas.client.ctx(callback, client)};
14    }
15</script>
16
17<a id="ctxlink" href="#">Get Context</a>