Default allowed tags and attributes

I found it a bit hard to find the default tags and attributes in the docs.

As of Rails 2.2.2 they are:

Tags

del, dd, h3, address, big, sub, tt, a, ul, h4, cite, dfn, h5, small, kbd, code,
b, ins, img, h6, sup, pre, strong, blockquote, acronym, dt, br, p, div, samp,
li, ol, var, em, h1, i, abbr, h2, span, hr

Attributes

name, href, cite, class, title, src, xml:lang, height, datetime, alt, abbr, width

Getting the latest list

You can query for this list yourself with the following code on the console:

>> puts helper.sanitized_allowed_tags.to_a * ", "
... will output tag list ...
>> puts helper.sanitized_allowed_attributes.to_a * ", "
... will output attribute list ...

The same principal can probably be applied to sanitize_css.

link_to_if for named routes

Back before named routes we used to say things like:

<%= link_to_if message.user, 'Poster', :controller => 'users',
  :action => 'show', :id => message.user %>

This would make the text “Poster” only link if message has a user. But with named routes this has become more complicated. Our first try is something like:

<%= link_to_if message.user, 'Poster', user_path(message.user) %>

Although this looks nice it causes an error since the path is generated prior to the condition not after the condition like using a hash is done. To get around this problem I have found two solutions:

• If you are linking to the “show” path then you can just pass the object. This will force the path to not be generated until after the condition (like a hash is done). For example:

  <%= link_to_if message.user, 'Poster', message.user %>
  

• The previous workaround works great if you want to link to the show action. But what if you want to link to another action (say the edit action). In this case the best way I have found is to use the hash_for* helpers generated with the routing resource. So:

  <%= link_to message.user, 'Poster',
    hash_for_edit_user_path(:id => message.user) %>
  

A little more awkward than the previous workaround but it is the best I can come up with. Any other suggestions (other than going back to manually typing the hash)?