CODEWITHSUNDEEP
ruby-on-railsrubyruby-on-rails-3
graphmeter
graphmeter

Reputation: 1125

Update field through link_to in Rails

I have a tree of products in Rails 3.2 and would like to have an add/remove feature so that users can add new children products or remove existing children for a product. I use the ancestry gem to generate the tree, for a Product 1 it might look like this:

Product 1
add | remove
    Product 2
    add | remove
        Product 3
        add | remove

In a partial _product.html.erb I have added Add and Remove links, which works for the add feature, but I cannot get the remove link to work:

<span><%= product.name.capitalize %></span>
<%= link_to "Add", new_product_path(parent_id: product) %> | 
<%= link_to "Remove", {parent_id: nil}, method: :update %>

I would like to update the parent_id to nil for the product to be removed when "Remove" is clicked, but the above link_to doesn't seem to be working. I get an: No route matches [POST] "/products/1/edit" routing error. In my product_controller I have: 

def update
   if @product.update_attributes(params[:product])
     flash[:success] = "Product updated"
     redirect_to @product
   else
     render 'edit'
  end
end

What am I doing wrong?

Edit:

I tried to use method: put instead:

<%= link_to "Remove", {parent_id: nil}, method: :put %>

then I get a No route matches [PUT] "/products/1/edit" error instead when clicking on the link.

I can now change/remove the parent using a form, not at all what I want but anyway:

<%= form_for @product do |f| %>    
    <%= f.label :parent_id %>
    <%= f.text_field :parent_id %>
    <%= f.submit "Update", class: "btn" %>  
<% end %>

Would it be possible to automatically pass the parent_id: nil into the form so that when you hit Update, it sets the parent_id: nil (not having a text field just a button)?

Upvotes: 3

Views: 6731

Answers (2)

graphmeter
graphmeter

Reputation: 1125

I finally got it to work thanks to @krichard answer together with @froderiks comment, by setting the path to /products/id and passing parent_id: nil using method: :put:

<%= link_to "Remove", "/products/#{product.id}?product%5Bparent_id%5D=", method: :put %>

The same effect can be achieved using form_for and a hidden_field (Passing a fixed value to a field using a button/link):

<%= form_for product do |f| %>
  <%= f.hidden_field :parent_id, value: nil %>
  <%= f.submit "Remove", class: "btn" %>
<% end %>

If a hidden_field_tag is used instead of f.hidden_field, :parent_id must be picked up in the controller (thanks @froderik):

<%= form_for product do |f| %>
  <%= hidden_field_tag :parent_id, nil %>
  <%= f.submit "Remove", class: "btn" %>
<% end %>

products_controller.rb

def update
  @product.parent_id = params[:parent_id]
  ...
end

Upvotes: 2

krichard
krichard

Reputation: 3694

Try 

<%= link_to "Remove", update_products_path(product:{parent_id: nil}), method: :put %>

There is no HTTP-Verb update what you need is put. You can read about Rails and HTTP-Verbs here

Upvotes: 7

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