cgi_escape filter

[vilcans]

I created a filter that escapes characters so they can safely be used in URLs.

I.e. "hey! you!" will be escaped as "hey%21+you%21".

See this branch: http://github.com/vilcans/jekyll/tree/cgi_escape

This is useful if you want to link to a tag summary page where tags potentially have spaces in them. So if tag is "interesting stuff", <a href="/tags/{{tag|cgi_escape}"> would link to /tags/interesting+stuff. I guess it can be used to link to a search engine as well.

(Oh, and standard Jekyll doesn't support tags, but it should, so replace tag with category or topic in the description above.)

[qrush]

I think xml_escape should be deprecated in favor of using cgi_escape, and cgi_escape should be renamed to simply escape. I don't see any reason why we shouldn't use this for all escaping needs. Any thoughts?

[vilcans]

I think we need both. xml_escape for escaping strings that are to be inserted into HTML or XML and that may contain <, > or &. cgi_escape for strings that goes into URLs and may contain space, #, % and other special characters.

[qrush]

Ah, I see the difference now. I merged your patch in and changed xml_escape to use CGI.escapeHTML. Thanks!