Routing for Admin area not working

I've got an application that makes use of an admin area for managing Articles on the frontend.
Its a simple CRUD app where pretty much everything Admin related is namespaced and inside admin folders eg: 'views/admin/...', 'controllers/admin/...', etc

The problem I've got is that the form I implemented for creating and changing Articles is not working at all, it seems to try to use the regular /articles/#post route instead of /admin/articles/#post

Form:

<%= form_with model: @article, method: :post do |f| %>
  <div class="form-group">
    <%= f.label :title %>
    <%= f.text_field :title, class: 'form-control input-lg' %>
  </div>
    <%= f.submit 'Create Article', class: 'btn btn-success' %>
<% end %>

Controller:

class Admin::ArticlesController < Admin::BaseController
  def new
    @article = Article.new
  end

  def create
    @article = Article.new(article_params)
    if @article.save
      redirect_to admin_articles_path
    else
      render json: @article
    end
  end

  def update
    @article = Article.find(params[:id])
    if @article.update(article_params)
      redirect_to admin_articles_path
    else
      render json: @article
    end
  end

  def edit
    @article = Article.find(params[:id])
  end

  def destroy
    @article = Article.find(params[:id])
    @article.destroy
    redirect_to admin_articles_path
  end

  def index
    @page_title = 'Articles'
    @articles = Article.all.order(:created_at)
  end

  def show
    @article = Article.find(params[:id])
  end

  private
  def article_params
    params.require(:article).permit(:title, :excerpt, :content, :category_id, :tags_as_string)
  end
end

Routes:

Rails.application.routes.draw do
  devise_for :users

  root 'home#index'

  get 'admin' => 'admin/dashboard#index'
  get 'about' => 'home#about'
  get 'contact' => 'home#contact'

  resources :documents, only: [:index, :show]
  resources :questions, only: [:index]
  resources :categories, only: [:show]
  resources :articles, only: [:index, :show]

  namespace :admin do
    resources :documents
    resources :users
    resources :questions
    resources :categories
    resources :articles
  end
end

Rake routes (Grep article):

                 articles GET    /articles(.:format)                                                                      articles#index
                  article GET    /articles/:id(.:format)                                                                  articles#show
           admin_articles GET    /admin/articles(.:format)                                                                admin/articles#index
                          POST   /admin/articles(.:format)                                                                admin/articles#create
        new_admin_article GET    /admin/articles/new(.:format)                                                            admin/articles#new
       edit_admin_article GET    /admin/articles/:id/edit(.:format)                                                       admin/articles#edit
            admin_article GET    /admin/articles/:id(.:format)                                                            admin/articles#show
                          PATCH  /admin/articles/:id(.:format)                                                            admin/articles#update
                          PUT    /admin/articles/:id(.:format)                                                            admin/articles#update
                          DELETE /admin/articles/:id(.:format)                                                            admin/articles#destroy

Puma logs:

Started POST "/articles" for 127.0.0.1 at 2019-01-27 06:39:16 -0300

ActionController::RoutingError (No route matches [POST] "/articles"):

Any idea how to force the use of the admin controller?

You can just pass in an array of items to tell Rails the correct scoping when it generates the route in the form.

<%= form_with model: [:admin, @article], method: :post do |f| %>

The url option works as well, like eelcoj mentioned, but you'll more commonly see the model being used for forms that are for models. The url option is normally used for custom forms that aren't model backed.

Amazing! Thank yous very much! All working now... Initially It was only Creatint but not saving but I just removed the method: :post

I got this issue this noon and it has been solved by following this thread. Thanks guy.