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suppressing NoMethodError when receiver is nil, within a block (See related posts)

Often in rails you'll do things like

<%= %>

but it may be that you have no post, or the post has no author, and even if that's ok, the above would raise. I came up with a solution that lets you do the following:

<%= ifnil("no author"){ } %>

If at any point the receiver is nil (either @post or #author), execution of the block is stopped and the default value is returned ("no author" in this case, but defaults to nil)

NoMethodError is still raised if you send an invalid message to a non-nil receiver.

Here's the code for ifnil

def ifnil(value=nil)
  rescue NoMethodError
  raise unless $!.message =~ /:NilClass$/

Comments on this post

nachokb posts on Aug 01, 2007 at 17:50
I'm used to do this
<%= rescue "no author" -%>

But this way you can't specify a specific error to rescue...

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