WithAction

A respond_to style helper for doing different actions based on which request parameters are passed. Specifically, it is helpful if you want to use multiple form buttons on a page, such as “Save”, “Save and Continue Editing”, and “Cancel”. with_action executes different blocks based on what the presence of request parameters.

def create
  with_action do |a|
    a.cancel { redirect_to articles_path }
    a.any do
      @article = Article.new(params[:article])
      if @article.save
        a.save { redirect_to article_path(@article) }
        a.edit { redirect_to article_path(@article) }
        a.approve do
          @article.approve!
          redirect_to article_path(@article)
        end
      else
        render :action => 'new'
      end
    end
  end
end

A block is invoked if a parameter with the same name exists and is not blank. Here is an example of a form to submit to this action:

<%= submit_tag 'Save', :name => 'save' %>
<%= submit_tag 'Save & Continue Editing', :name => 'edit' %>
<%= submit_tag 'Save & Approve', :name => 'approve' %>
<%= submit_tag 'Cancel', :name => 'cancel' %>

If an @any@ block is present and no parameter that matches one of the other blocks, it is called by default, otherwise the first block will be called. The @any@ block is the only one that can have nesting and be called multiple times.

If a block is not passed to the action, then a method with the same name is called on the controller:

def update
  with_action do |a|
    a.publish
    a.reject
    a.any { redirect_to root_path }
  end
end

def publish
  # …
end

def reject
  # …
end

Which can be abbreviated as:

def update
  with_action(:publish, :reject) do |a|
    a.any { redirect_to root_path }
  end
end