Rails respond_to in the controller

Question

This is the code from internet and I am having trouble understanding what does respond_to, format.html and format.js do in the controller.

def create
 @review = Review.create!(params[:review])
 flash[:notice] = "Thank you for reviewing this product"
  respond_to do |format|
   format.html { redirect_to @review.product }
   format.js
 end
end

Thank you for your time.

Ramya

wizztjh wizztjh · Accepted Answer · 2013-03-05T06:21:49

respond_to(*types, &block) public Without web-service support, an action which collects the data for displaying a list of people might look something like this:

  def index
    @people = Person.find(:all)
  end

Here’s the same action, with web-service support baked in:

  def index
    @people = Person.find(:all)

    respond_to do |format|
      format.html
      format.xml { render :xml => @people.to_xml }
    end
  end

What that says is, "if the client wants HTML in response to this action, just respond as we would have before, but if the client wants XML, return them the list of people in XML format." (Rails determines the desired response format from the HTTP Accept header submitted by the client.)

Supposing you have an action that adds a new person, optionally creating their company (by name) if it does not already exist, without web-services, it might look like this:

  def create
    @company = Company.find_or_create_by_name(params[:company][:name])
    @person  = @company.people.create(params[:person])

    redirect_to(person_list_url)
  end

Here’s the same action, with web-service support baked in:

  def create
    company  = params[:person].delete(:company)
    @company = Company.find_or_create_by_name(company[:name])
    @person  = @company.people.create(params[:person])

    respond_to do |format|
      format.html { redirect_to(person_list_url) }
      format.js
      format.xml  { render :xml => @person.to_xml(:include => @company) }
    end
  end

If the client wants HTML, we just redirect them back to the person list. If they want Javascript (format.js), then it is an RJS request and we render the RJS template associated with this action. Lastly, if the client wants XML, we render the created person as XML, but with a twist: we also include the person’s company in the rendered XML, so you get something like this:

http://apidock.com/rails/ActionController/MimeResponds/InstanceMethods/respond_to

Rails respond_to in the controller

1 Answers