[SHINDIG-1808] makeRequest fails on IE when ActiveX is disabled

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 2.5.0-beta3
• Component/s: Javascript
• Environment: Internet Explorer 7+
• Assignee: Stanton Sievers
• Reporter: Matthew Reiter
• Created: 19/Jun/12 21:30
• Updated: 29/Jun/12 21:08
• Resolved: 29/Jun/12 17:15

Description

When using Internet Explorer and ActiveX is disabled, makeRequest throws an exception creating the Msxml2.XMLHTTP ActiveXObject rather than falling back to XMLHttpRequest. This bug was introduced as part of the fix for the bug "IE7 XHR requests fail when gadgets contain a <base href="..."> tag" (https://issues.apache.org/jira/browse/SHINDIG-1194) because the order in which the two methods are attempted was reversed. The Wicket project encountered the same bug: "Problems concerning IE9 with "ActiveX Filtering" enabled" (https://issues.apache.org/jira/browse/WICKET-3887), but Shindig may not be able to make use of their fix due to the issues raised in the first bug. Thus my proposed solution is to wrap the ActiveXObject creation in a try-catch block and fall back to XMLHttpRequest if an error is encountered.

Once that is out of the way, the same error will occur again later when attempting to parse the DOM (assuming that XML was returned) when creating Microsoft.XMLDOM because it doesn't fall back to DOMParser. For this, I propose reversing the order in which the two methods are attempted (try DOMParser first and then try Microsoft.XMLDOM if it fails) under the assumption that using DOMParser is the preferred method of parsing XML.