find_or_redirect¶ ↑

Find or Redirect helps you refactor out model finding code in your controllers.

Installation¶ ↑

Enable gemcutter, then just:

gem install find_or_redirect

Usage¶ ↑

This is a common pattern in rails:

class ModelsController < ApplicationController
  def show
    @model = Model.find(params[:id])
  end

  def destroy
    @model = Model.find(params[:id])
    @model.destroy
  end  
end

Not so dry! Also, this throws exceptions if the model can’t be found. Find or Redirect improves on that by using “find_by_id” and catching a miss with a redirection and friendly flash message.

It’s like you did this:

class ModelsController < ApplicationController
  before_filter :find_model
  def show
  end

  def destroy
    @model.destroy
  end  

  private

  def find_model
    @model = Model.find_by_id(params[:id])
    unless @model
      redirect_to :action => :index
      flash[:error] = "Invalid model id"
      return false
    end
  end
end

But it gets repetitive doing that in all your controllers, and it’s certainly not DRY.

So how about:

class ModelsController
  find_or_redirect :only => [ :show, :destroy ]

  def show
  end

  def destroy
    @model.destroy
  end
end

The class variable is inferred from the controller name. All options passed to find_or_redirect are automatically passed along to the before_filter created, so you can use :only and :except.

Additional Options¶ ↑

redirect_to¶ ↑

Redirect to a path other than this controller’s index

find_or_redirect :redirect_to => "root_path"
find_or_redirect :redirect_to => ":action => :index"
find_or_redirect :redirect_to => "'http://www.google.com'"

name¶ ↑

Specify the name of the variable to set

find_or_redirect :name => "something_else"

def destroy
  @something_else.destroy
end

finder¶ ↑

Find the model in a different fashion (helpful when the controller name doesn’t match the finder, or if you want to use multiple find_or_redirects)

class ParentsController
  # this automatically finds the parent
  find_or_redirect
  # now we'll find the child from the parent's children and param
  find_or_redirect(
    :name => "child"
    :finder => "@parent.children.find_by_id(params[:child_id])"
  )
  # and grab the tag the user requested
  find_or_redirect(
    :name => "tag",
    :finder => "Tag.find_by_slug(params[:tag])"
  )

  def update_child_tag
    @child.tag = @tag
    @child.save!
    @parent.last_tag = @tag
    @parent.save!
  end
end

Note on Patches/Pull Requests¶ ↑

• Fork the project.

• Make your feature addition or bug fix.

• Add tests for it. This is important so I don’t break it in a future version unintentionally.

• Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but

  bump version in a commit by itself I can ignore when I pull)

• Send me a pull request. Bonus points for topic branches.

Copyright¶ ↑

Copyright © 2009 Nick Gauthier. See LICENSE for details.