Old modules and plugins

Note: This database has been replaced by the Moodle Plugins Directory.

Block: Browser Capability Block

browser-capability
Type: Block
Requires: Moodle 1.5 or later
Status: Contributed
Maintainer(s): Dean Stringer - University of Waikato

This block allows a teacher to indicate which browser plug-ins students are likely to require in the course based on the content they are intending to include. The plug-ins they choose are stored against the instance of the block for the course the block has been added to.

Students will see a tick or a cross against each one of the plug-ins selected indicating whether or not their browser seems to support the plug-in.

There is no embedded help for users as to how to locate or install any missing plug-ins, its simply an indication as to whether they seem to have them currently installed.

Implementation details:

This solution as implemented is to use the navigator.* methods supported by Mozilla, Firefox and early IE browsers to establish if support may be available. And to create an ActiveX object in later IE versions with some VBScript. Although the navigator.* method is not as reliable it gives a reasonable indication without the overhead of actually instantiating each individual object type.

Most comprehensive plug-in detection solutions achieve detection through attempting to instantiate an instance of the object in question by including an <object> tag in the output, then checking to see if that object exists or is able to be queried through its methods/properties. If not the detector assumes the plug-in is not available or is disabled.

The instantiation method is effective, but also places an increased processing and network burden on the browser, and potentially the back-end server, which may not be appropriate on a page which is heavily or frequently visited.

The block does not require any additional database fields or tables and should be supported by any back-end Moodle version >= 1.5 (has been specifically tested in 1.7, 1.8 & 1.9). It has also been tested in JavaScript enabled browsers IE7, FF2 and Safari3 (a warning is presented in the block to the user if JavaScript not enabled).

Development of this block is discussed here:
http://moodle.org/mod/forum/discuss.php?d=94932

Possible future changes to this block:

  • check for specific versions of plug-ins (lots of work)
  • inspect uploaded or linked content in a course and automatically populate the plug-in list based on extensions
  • a page with instructions or links to installers for each plug-in
  • integration with the Moodle check_browser_version() sub
  • check for XML support (ie NN7+, IE6+, FF1+ etc)
Other plug-detection approaches:

Jamie Pratt describes using the instantiation method to detect the flash player in this thread:
http://moodle.org/mod/forum/discuss.php?d=20943

Also mentioned is Hixie's workaround for the <embed> element missing in HTML4 problem:
http://ln.hixie.ch/?start=1081798064&count=1

California State University - Web Browser Check Up
http://ilearn.csumb.edu/BrowserTestFiles/index.php

moock fpi - flash detection
http://moock.org/webdesign/flash/detection/moockfpi/

Detecting plugins in Internet Explorer
http://www.builtfromsource.com/2007/06/26/


Record added by Dean Stringer - Thursday, 5 June 2008, 11:11 AM
Last modified - Thursday, 5 June 2008, 11:22 AM