Passing parameters from view to controller

问题

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 :)

回答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

回答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?

来源：https://stackoverflow.com/questions/13672155/passing-parameters-from-view-to-controller