Rails 4 error "param is missing or the value is empty:" in create

Question

I've looked at several tutorials, the ruby guides, and several stackoverflow questions. I tried first with simple_form and now the old fashioned way and can't figure out why the params aren't being passed. Controller: ``` def new @topgem = Topgem.new end def create @topgem = Topgem.new(topgem_params) if @topgem.save redirect_to @topgem else render 'new' end ``` ... ``` private def topgem_params params.require(:name).permit(:url, :description, :downloads, :last_updated) end ``` Model: ``` class Topgem < ActiveRecord::Base has_many :votes has_many :users, through: :votes validates :name, presence: true, uniqueness: true, :length => { :minimum =>2, :maximum =>50} validates :url, presence: true validates :description, presence: true validates :downloads, numericality: { only_integer: true } end ``` new.html.erb ``` <%= form_for(@topgem) do |f| %> <%= f.label :name %>: <%= f.text_field :name %>
<%= f.label :url %>: <%= f.text_field :url %>
<%= f.label :description %>: <%= f.tex…

Accepted Answer

You have required `params[:name]`, but the actual params are `params[:topgem][:name]`.

Change your `topgem_params` method to

```
params.require(:topgem).
  permit(
    :name,
    :url,
    :description,
    :downloads,
    :last_updated
  )
```

Rails 4 error "param is missing or the value is empty:" in create

Solution

Problem