[Rails] Calling a method from a view using link_to_function

Question

Hello! I'm trying to have an image that when clicked associates the selected guideline to a project. I'm using link_to_function which somewhat behaves but I can not get the method I am calling in the link_to_function to redirect to another page. Is there a better way to do this? Below is a bit of my code. I can paste in additional parts if necessary:

<% @guidelines.each do |guideline| %>
 <tr>
    <td align='center'><%= link_to_function image_tag("../../../images/icons/action_add.png"), add_guideline(guideline)  %></td>
          <td><%=h guideline.title %></td>

My GuidelinesController.helper method looks like this:

  def add_guideline(guideline)
           @project = Project.find(params[:project_id])
           @project.guidelines << guideline
           @project.save   

           redirect_to dashboard_path #doesn't work :(
    end

Answer 1

The Problem

link_to_function is for adding Javascript to your links.

in your code, add_guideline is being called and its result is being passed as the second argument to your link_to_function call.

---

EDIT

Checkout how to Add more RESTful actions

You can add this to config/routes.rb

# overwrite map.resources :projects
map.resources :projects, :member => {
  :add_guideline    => :get,
  :create_guideline => :post
}

This will add the following routes

   add_guideline_project GET    /projects/:id/add_guideline(.:format)
create_guideline_project POST   /projects/:id/create_guideline(.:format)

In your view, you can use

<%= link_to(
  image_tag("/images/icons/action_add.png"),
  add_guideline_project_path(@project)
) %>

This will link to ProjectsController#add_guideline.

Here you can do what you've been trying:

# app/controllers/projects_controller.rb
def add_guideline
  @project = Project.find(params[:id])

  # render app/views/projects/add_guideline.html.erb
  # create your form in this view
end

def create_guideline
  @project = Project.find(params[:project_id])
  @guideline = Guideline.find(params[:guideline_id])
  @project.guidelines << @guideline
  redirect_to dashboard_path
end

Answer 2

The helper is evaluated and result returned before the page is rendered... link_to_function uses JavaScript client-side after the page has been rendered.

Guessing from your code, you should probably have an action in your controller that take project_id and guideline_id to add a guideline to a project. Your link should then reflect this such as projects_add_guideline_path(project, guideline) with the contents of your helper in the new action.

In view:

link_to projects_add_guideline_path(@project, guideline)

In controller:

def add_guideline_to_project
  @project = Project.find(params[:project_id])
  @guideline = Guideline.find(params[:guideline_id])
  @project.guidelines << @guideline
  @project.save   
  redirect_to dashboard_path 
end

Answer 3

I got this working by using

<%= link_to(image_tag("/images/icons/action_add.png"), add_guideline_to_project_path(@project, :guideline_id => guideline.id))  %></td>
    <td><%=h guideline.title %></td>

and this method:

  def add_guideline_to
    @project = Project.find(params[:id])
    @guideline = Guideline.find(params[:guideline_id])
    @project.guidelines << @guideline
    @project.save

    redirect_to @project
  end

I also updated my routes to include:

map.resources :projects, :member => {
  :add_guideline    => :get,
  :create_guideline => :post
}

Thanks everyone!