I'm getting the error:
undefined form_with for #<#<Class:0x7ac62e0>:0x551e5a8>
in articles#new
The error occurs in the following file: new.html.erb
Which has:
<%= form_with(model: [@article] , local: true) do |f| %>
<p>
<%= f.label :title %><enter code here`br>
<%= f.text_field :title %>
</p>
And the controller articles_controller.rb has:
class ArticlesController < ApplicationController
def new
end
end
your controller just has new command see sample below for create instance variable @article
articles_controller.rb
class ArticlesController < ApplicationController
def new
@article = Article.new
end
end
new.html.erb
<%= form_with @article do |f| %>
<%= f.label "Enter title: " %>
<%= f.text_field :title %>
<% end %>
I've seen this error while working on nested routes. It occurred when the controller routes are defined as nested under another controller's route.
For example:
resources :authors do
resource :books, only: [index, :new]
end
it will create following routes:
/authors/author_id/books/:id
/authors/author_id/books/new
The method form_with try to execute the method book_path. But it is defined as author_books_path.
I found the solution by adding extra resources :books outside of the resources :books block.
resources :books
resources :authors do
resource :books, only: [:index, :new]
end
Edit:
This solution will build the form without error but action URL won't be be correct because it will use books/.. instead of author/:author_id/books. That's why it is better use form_for instead of form_with while working on nested routes by passing parent and child model in a array.
<% form_for [@author, @book] do |form| %>
