feat(example): add example app and blog app with demos

examples/blog/app/controllers/posts_controller.rb

@@ -0,0 +1,24 @@
+class PostsController < Prism::Controller
+  layout :application
+
+  def index
+    render(:index, locals: { posts: Post.order(:created_at, :desc), notice: flash[:notice], errors: [] })
+  end
+
+  def show
+    render(:show, locals: { post: Post.find(params['id']) })
+  rescue Prism::Orm::RecordNotFound
+    halt(404, 'Post not found')
+  end
+
+  def create
+    post = Post.new(title: params['title'], body: params['body'])
+    if post.save
+      flash[:notice] = "Post ##{post.id} created"
+      redirect url_for(:posts)
+    else
+      status(422)
+      render(:index, locals: { posts: Post.order(:created_at, :desc), notice: nil, errors: post.errors.full_messages })
+    end
+  end
+end

examples/blog/app/models/post.rb

@@ -0,0 +1,3 @@
+class Post < Prism::Orm::Model
+  validates :title, presence: true, length: { minimum: 3 }
+end

examples/blog/app/views/layouts/application.erb

@@ -0,0 +1,5 @@
+<!doctype html>
+<html>
+  <head><title><%= defined?(title) ? title : 'Prism App' %></title></head>
+  <body><%== content %></body>
+</html>

examples/blog/app/views/posts/_post.erb

@@ -0,0 +1,4 @@
+<li class="post" id="post-<%= post.id %>">
+  <h2><%= post.title %></h2>
+  <p><%= post.body %></p>
+</li>

examples/blog/app/views/posts/index.erb

@@ -0,0 +1,21 @@
+<h1>Blog</h1>
+<% if notice %>
+<p class="notice"><%= notice %></p>
+<% end %>
+<% unless errors.empty? %>
+<ul class="errors">
+<% errors.each do |message| %>
+<li><%= message %></li>
+<% end %>
+</ul>
+<% end %>
+<form method="post" action="/posts">
+  <input type="text" name="title" placeholder="Title">
+  <textarea name="body" placeholder="Body"></textarea>
+  <button type="submit">Create post</button>
+</form>
+<ul class="posts">
+<% posts.each do |post| %>
+<%== partial('post', locals: { post: post }) %>
+<% end %>
+</ul>

examples/blog/app/views/posts/show.erb

@@ -0,0 +1,2 @@
+<h1><%= post.title %></h1>
+<p><%= post.body %></p>