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Catalyst::TraitFor::Request::REST::ForBrowsers(3pm) User Contributed Perl Documentation Catalyst::TraitFor::Request::REST::ForBrowsers(3pm)


Catalyst::TraitFor::Request::REST::ForBrowsers - A request trait for REST and browsers


    package MyApp;
    use Moose;
    use namespace::autoclean;
    use Catalyst;
    use CatalystX::RoleApplicator;
    extends 'Catalyst';


Writing REST-y apps is a good thing, but if you're also trying to support web browsers, you're probably going to need some hackish workarounds. This module provides those workarounds for you.

Specifically, it lets you do two things. First, it lets you "tunnel" PUT and DELETE requests across a POST, since most browsers do not support PUT or DELETE actions (as of early 2009, at least).

Second, it provides a heuristic to check if the client is a web browser, regardless of what content types it claims to accept. The reason for this is that while a browser might claim to accept the "application/xml" content type, it's really not going to do anything useful with it, and you're best off giving it HTML.


This class provides the following methods:


This method works just like "Catalyst::Request->method()" except it allows for tunneling of PUT and DELETE requests via a POST.

Specifically, you can provide a form element named "x-tunneled-method" which can override the request method for a POST. This only works for a POST, not a GET.

You can also use a header named "x-http-method-override" instead (Google uses this header for its APIs).


This attribute provides a heuristic to determine whether or not the request appears to come from a browser. You can use this however you want. I usually use it to determine whether or not to give the client a full HTML page or some sort of serialized data.

This is a heuristic, and like any heuristic, it is probably wrong sometimes. Here is how it works:

  • If the request includes a header "X-Request-With" set to either "HTTP.Request" or "XMLHttpRequest", this returns false. The assumption is that if you're doing XHR, you don't want the request treated as if it comes from a browser.
  • If the client makes a GET request with a query string parameter "content-type", and that type is not an HTML type, it is not a browser.
  • If the client provides an Accept header which includes "*/*" as an accepted content type, the client is a browser. Specifically, it is IE7, which submits an Accept header of "*/*". IE7's Accept header does not include any html types like "text/html".
  • If the client provides an Accept header and accepts either "text/html" or "application/xhtml+xml" it is a browser.
  • If it provides an Accept header of any sort that doesn't match one of the above criteria, it is not a browser.
  • The default is that the client is a browser.

This all works well for my apps, but read it carefully to make sure it meets your expectations before using it.


Dave Rolsky, "<>"


Please report any bugs or feature requests to "", or through the web interface at <>. We will be notified, and then you'll automatically be notified of progress on your bug as I make changes.


Copyright 2008-2010 Dave Rolsky, All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

2022-06-09 perl v5.34.0