Question

I want to load a partial using AJAX in my create action. From tutorials I know the way to do this is to include the line format.js alone by itself in the respond_to block and create a create.js.erb file. But I have code in my create action which I need executed. If I put all of this code within a format.js {} block the partial doesn’t get loaded. I guess I’m not sure what should be included inside this block?

This sort of works:

def create
  respond_to do |format|

  format.html do
    session[:user_params].deep_merge!(params[:user]) if params[:user]
    @user = User.new(session[:user_params])
    @user.current_step = session[:user_step]
    if params[:prev_button]
      @user.previous_step
    elsif @user.last_step?
      @user.save
    else
      @user.next_step
    end
    session[:user_step] = @user.current_step
    if @user.new_record?
      render :new
    else
      session[:user_step] = session[:user_params] = nil
      flash[:success] = "Welcome to Friends First!"
      redirect_to @user
    end
  end
  format.js
end
end

My new.html.erb looks like this:

<%= form_for(@user, :html => { :class => "form-horizontal" }, remote: true) do |f| %>
  <%= render 'shared/error_messages' %>

  <div id="partial">
    <%= render "#{@user.current_step}", :f => f %>
</div>

<div class="control-group">
  <div class="controls">
    <%= f.submit "Previous", class: "btn btn-primary", :name => "prev_button" unless @user.first_step? %>
    <%= f.submit "Next", class: "btn btn-primary" %>
  </div>
</div>

But for some reason @user.first_step? is not working once I load a partial.

create.js.erb

$("#partial").html("<%= escape_javascript(render('step2')) %>");

What I really want is this: render(@user.current_step)

Answer 1

You can do all your logic and then handle proper format. Furthermore you can use more than one format for your views.

There is and example from Diaspora source code:

  def create
    post = current_user.find_visible_shareable_by_id(Post, params[:post_id])
    @comment = current_user.comment!(post, params[:text]) if post

    if @comment
      respond_to do |format|
        format.json{ render :json => CommentPresenter.new(@comment), :status => 201 }
        format.html{ render :nothing => true, :status => 201 }
        format.mobile{ render :partial => 'comment', :locals => {:post => @comment.post, :comment => @comment} }
      end
    else
      render :nothing => true, :status => 422
    end
  end

You shouldn’t do any redirects if something fail because user stay at page anyway. But you might want use client-side validation.

So you might use format.js for your success case and reload part of your HTML using partial. For example:

# create.js.erb
$("#js-user-panel").html("<%= j render("users/panel", :user => @user %>");
# ... create div with flash message here and etc.