CODEWITHSUNDEEP
ruby-on-railsrubyrescue
user749798
user749798

Reputation: 5380

Undefined method `first' for nil:NilClass

Sometimes I get this error, and I just want Rails to rescue/skip the error when it happens rather than stop the program completely. Is there a good way to do this?

Below is my code:

<% wiki = MediaWiki.new(:domain => 'commons.wikimedia.org') %>
<% wikimedia_user = wiki.find("File:Samuel_L_Jackson_as_Nick_Fury.jpg") %>

The second line causes this error:

NoMethodError (undefined method `first' for nil:NilClass)

If that happens, I just want wikimedia_user to be set to nil. I tried adding .inspect? to the end of the .find, but all I get is the error. Is there a way to do this?

Upvotes: 0

Views: 1670

Answers (1)

Chris Cherry
Chris Cherry

Reputation: 28574

On the same line as the one you want to suppress the exception and return nil on, add rescue nil to the end.

<% wikimedia_user = wiki.find("File:Samuel_L_Jackson_as_Nick_Fury.jpg") rescue nil %>

Note: This isn't generally considered a good practice, as any kind of exception thrown from that line will be caught by that rescue. In your case, it's probably not a big problem, but something to keep in mind moving forward.

Upvotes: 3

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