How to comment code in Rails views?

问题:

As I'm playing with Rails and developing views I often want to comment out code. Simple enough with classes & models but views are a bit more tricky.

What's best way to comment code in a view so it's not interpreted by, well, anything... HTML gives us <!-- commented Rails code here --> though code enclosed here seems to get interpreted anyway?!? Or is there a more Railsy way?

回答1:

<% code code # comment %> USED to work but I think that was accidental.

You were always supposed to put comments in separate comment tags <%# comment %>

Note NO SPACE before the pound.

Now the old loophole is closed (I forget whether 'now' means Ruby 1.8 or Rails 3 or what) so that:

<% code code  #  this runs too %>
<% # also runs %>
<%# the only way to comment out %>

回答2:

I use this all the time

<%# This is a comment %>

回答3:

The reason Ruby code would be executed inside <!-- --> HTML comments is because all of the server side code (ie. Ruby) is interpreted first, and then the output is sent to the client, at which point the browser interprets <!-- --> as a comment. As the other answers said, use <% #comment %> to comment within a Rails view.

回答4:

Although (and i'm hoping to be corrected here) you have to be careful because i've had some really strange behavior when doing something like this:

<% if (my_boolean) # Commenting on this if-block %>

where it will affect the HTML that directly follows that (even if it's on another line).

Anyone?

And would this qualify as an answer, or a comment?

回答5:

<% #comment here %>

:D