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We don't need if condition like this because `respond_with` take care about errors:

> for an html response - if the request method is get, an exception is raised but for other requests such as post the response depends on whether the resource has any validation errors (i.e. assuming that an attempt has been made to save the resource, e.g. by a create action) -

> If there are no errors, i.e. the resource was saved successfully, the response redirect's to the resource i.e. its show action.

> If there are validation errors, the response renders a default action, which is :new for a post request or :edit for patch or put.

See more: http://apidock.com/rails/v4.0.2/ActionController/MimeResponds/respond_with.