Question

I’m looking to turn all words preceeded by a # (ie #stackoverflow) into a link that when clicked through will link to the search page with the word as a query.

I tried this recently and got the right HTML being returned, but because content is automatically escaped it showed as:

This is some content <a href="search?q=something">something</a>

My question is: Is there any way to only apply html_safe to every part of the content except for these links?

Answer 1

If your tags are simple alphanumeric strings (i.e. nothing that needs to be HTML or URL encoded), then you could do something like this:

s = ERB::Util.html_escape(text_to_be_linkified).gsub(/#(\w+)/, '<a href="search?q=\1">\1</a>').html_safe

Then s.html_safe? will be true and <%= ... %> will pass the result through as-is. If you put this in a view helper, then you shouldn’t need the ERB::Util. prefix on html_escape. If you do need to worry about URL or HTML encoding then you could modify the gsub replacement string appropriately.

For example:

> s = ERB::Util.html_escape('<pancakes & #things').gsub(/#(\w+)/, '<a href="search?q=\1">\1</a>').html_safe
> puts s.html_safe?
true
> puts s
&lt;pancakes &amp; <a href="search?q=things">things</a>