Add basic form for example post with delegated type

Author: rossta

app/controllers/examples/posts_controller.rb

@@ -0,0 +1,20 @@
+class Examples::PostsController < ApplicationController
+  def index
+    postable = case params[:type]
+    when "link"
+      Examples::Posts::Link.new
+    when "image"
+      Examples::Posts::Image.new
+    else
+      Examples::Posts::Markdown.new
+    end
+
+    post = Examples::Post.new(postable: postable)
+
+    render Examples::Posts::IndexView.new(post: post)
+  end
+
+  def create
+    raise params.inspect
+  end
+end

app/views/examples/posts/index_view.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+class Examples::Posts::IndexView < ApplicationView
+  include Phlex::Rails::Helpers::FormWith
+  include Phlex::Rails::Helpers::LinkTo
+
+  def initialize(post:)
+    @post = post
+  end
+
+  def view_template
+    render Pages::Header.new(
+      title: "Examples: Posts",
+      description: "This is an example for creating a post of different types, like text, link, or image."
+    )
+
+    div(class: "section-content container py-gap") do
+      div(class: "tabs") do
+        link_to "Text", examples_posts_path
+        link_to "Link", examples_posts_path(type: "link")
+        link_to "Image", examples_posts_path(type: "image")
+      end
+
+      form_with model: @post, url: examples_posts_path, method: :post do |form|
+        fieldset do
+          form.label :title
+          form.text_field :title, placeholder: "My Post 🎸", required: true
+        end
+
+        form.fields_for :postable, @post.postable do |postable_form|
+          case @post.postable
+          when Examples::Posts::Markdown
+            fieldset do
+              postable_form.label :body, "Text (Markdown)"
+              postable_form.text_area :body, placeholder: "# This is a post about guitars 🎸", required: true
+            end
+          when Examples::Posts::Link
+            fieldset do
+              postable_form.label :url, "Link URL"
+              postable_form.text_field :url, placeholder: "https://example.com", required: true
+            end
+          when Examples::Posts::Image
+            fieldset do
+              postable_form.label :url, "Image URL"
+              postable_form.text_field :url, placeholder: "https://example.com/image.jpg", required: true
+            end
+          end
+        end
+
+        fieldset do
+          form.submit "Save", class: "button primary"
+        end
+      end
+    end
+  end
+end

config/routes.rb

@@ -13,6 +13,7 @@
   namespace :examples do
     resource :counters, only: [:show, :update, :destroy]
     resource :hello, only: [:show]
+    resources :posts, only: [:index, :create]
   end
   resources :examples, only: [:index, :show]
 

spec/requests/examples/posts_spec.rb

@@ -0,0 +1,10 @@
+require "rails_helper"
+
+RSpec.describe "Examples::Posts", type: :request do
+  describe "GET /index" do
+    it "is successful" do
+      get examples_posts_path
+      expect(response).to have_http_status(:success)
+    end
+  end
+end

spec/system/examples/posts_spec.rb

@@ -0,0 +1,30 @@
+require "rails_helper"
+
+RSpec.describe "Examples: Posts", type: :system do
+  it "renders the form" do
+    visit examples_posts_path
+
+    within "form" do
+      expect(page).to have_content("Title")
+      expect(page).to have_content("Markdown")
+    end
+
+    click_link "Link"
+
+    within "form" do
+      expect(page).to have_content("Title")
+      expect(page).to have_content("Link URL")
+
+      expect(page).not_to have_content("Markdown")
+    end
+
+    click_link "Image"
+
+    within "form" do
+      expect(page).to have_content("Title")
+      expect(page).to have_content("Image URL")
+
+      expect(page).not_to have_content("Link URL")
+    end
+  end
+end