Welcome back to our ongoing series on the technical side of UniBrows features. Today we’re focused on custom Content Handlers.
Content Handlers are all about downloads. They give administrators the ability to mandate specific procedures that are taken when files are downloaded (i.e. open a certain type of file with a specific program or run a command on a downloaded file when the file has a specific extension). Additionally, due to limitations in Internet Explorer, Content Handlers are necessary in order to perform any form of file download when using the Internet Explorer 6 Engine. If users of a Profile that uses the Internet Explorer 6 Engine would like to perform any type of file downloading on sites rendered by that Profile, the file types that they would like to download must have specific entries in a Content Handler enabling their download. Otherwise, users will not be able to download the files. Downloads can be performed without any entries in a Content Handler on any other Profile that doesn’t use the Internet Explorer 6 Engine, assuming that the administrator has disabled sandboxing on that Profile. Please remember that these restrictions only apply to sites being handled by a UniBrows rule & profile – this does not apply to sites rendered with the native browser (IE8 or IE9).
Regardless of whether a Content Handler is necessary to enable file downloading on the Profile that you are concerned with, Content Handlers provide a great way for administrators to manage the types of files that users are able to download and what is done with those files as soon as they are downloaded (e.g. passing all files through a virus scanner).
Features / Interface
The following screenshot was taken off the Content Handlers tab:
The Content Handlers Tab consists of the following features:
Managing Content Handlers with the UniBrows editor
The Content Handler Editor window is where all configurations and settings are managed for individual Content Handlers.
This editor offers you the ability to configure the following properties of a Content Handler:
The following screenshot of a Handler Editor window illustrates the solution to a common scenario where users of a web application that requires rendering in the Internet Explorer 6 Engine also need to be able to download .jpg files from the site. Another extension could be substituted for .jpg (i.e. .pdf, .doc, .xlsx, .png, etc.) and that file extension would then be supported.
The following screenshot of a Handler Editor instance outlines an example scenario where files of MIME type “application/pdf” are downloaded to a temporary location and passed to an application via a command line. The downloaded file is passed to the command line via the “%1” variable.
This powerful feature allows you to take explicit control of how Internet Explorer handles different file types when running under UniBrows, and is available in versions 1.2 and later of UniBrows.