Passing parameters from view to controller

Question

I got a bit of a newbie question. I'm trying to pass a variable from my view to my controller. Is there anyway my method in my controller can receive variables from my view?

Post view: show.html.erb:
....
<%=link_to "Add relationship", :method => :add_relationship(@rela) %>

---

Controller: post.controller.rb:

 def add_relationship(rela)
  @post = Post.find(params[:id])

  if current_user.id == @post.user_id
    @post.rel_current_id = rela.id
    @post.save
    redirect_to relationships_url
  else
    redirect_to posts_url, :notice => "FY!"
  end
end

Thanks in advance :)

Solution 1

You can add information to the params hash right through the link_to. I'm not sure exactly what you are trying to do but I did something like this recently to add the type of email I wanted when I link to the new email

<%= link_to 'Send Thanks', new_invoice_email_path(@invoice, :type => "thanks") %>

Now my params looks like:

{"type"=>"thanks", "action"=>"new", "controller"=>"emails", "invoice_id"=>"17"}

I can access the type via the params

email_type = params[:type]

Instead of a string, if you pass in the instance variable @rela you will get the object_id in the params hash.

Per the comment below, I'm adding my routes to show why the path new_invoice_email_path works:

resources :invoices do
  resources :emails
end

Solution 2

When a request comes in, the controller (and any model calls) will be processed first and then the view code gets processed last. The view can call methods in the helpers, but can't reference functions back in the controller.

However, once a page is rendered, you can either post information back to the controller as part of a new request or use ajax/JQuery (etc) to make a call to a controller function remotely.

Does that help?

Comments

[OXp1845]

Sorry, ajax is a little bit to complex for me :)

[OXp1845]

Yes, this is something that I am looking for. Is the new_invoice_email_path your controller or method? Pfft, I really need to learn more about this. I am more used to JAVA than ruby...

[Steve]

this route takes me to the email controller, new action. Email is a nested route for invoice, I'll add my routes to my answer above

[Chris Lewis]

open a command prompt and type 'rake routes' to see what defined routes you have. It also tells you what controller and action it maps to.