Error Handling with the AJAX Toolkit

The AJAX Toolkit provides the ability to handle errors for synchronous and asynchronous calls:

Error Handling for Synchronous Calls

If the API call fails, then the AJAX Toolkit throws an exception. The exception contains all the available error information. For example:

1<html>
2<head>
3    <script src="/soap/ajax/31.0/connection.js" type="text/javascript"></script>
4 
5    <script>
6 
7        function setupPage() {
8            var output = document.getElementById("output");
9            var startTime = new Date().getTime()
10
11             try {
12                var queryResult = sforce.connection.query("Select Id, Name, Industry From  
13                     Account order by Industry limit 30");
14                layoutResults(queryResult, output, startTime);
15            } catch(error) {
16                queryFailed(error, output);
17            }
18        }
19 
20        function queryFailed(error, out) {
21            out.innerHTML = "<font color=red>An error has occurred:</font> <p>" + error;
22        }
23 
24        function layoutResults(queryResult, out, startTime) {
25            var timeTaken = new Date().getTime() - startTime;
26 
27            if (queryResult.size > 0) {
28                var output = "";
29                var records = queryResult.getArray('records');
30 
31                for (var i = 0; i < records.length; i++) {
32                    var account = records[i];
33                    output += account.Id + " " + account.Name + " [Industry - "  
34                         + account.Industry + "]<BR>";
35                }
36 
37                out.innerHTML = output + "<BR> query complexted in: " + timeTaken + " ms.";
38            } else {
39                out.innerHTML = "No records matched.";
40            }
41        }
42 
43    </script>
44</head>
45
46 <body onload="setupPage()">
47<div id="output"></div>
48</body>
49</html>

Error Handling for Asynchronous Calls

For asynchronous calls, the onFailure property of the asynchronous object is called. For example:

1connection.query("Select Name From Account", 
2   {onSuccess: displayResult,
3       onFailure: queryFailed});
4
5function displayResult(result){}
6function queryFailed(error){}

If the onFailure property was not defined, the AJAX Toolkit pops up a new read-only browser window showing the error.

AJAX Toolkit Developer's Guide

No Results

Error Handling with the AJAX Toolkit

Error Handling for Synchronous Calls

Error Handling for Asynchronous Calls