Web Programming - Part 2: Ruby

# Web Programming

# Data

# Objects Specific "Things" in ruby

# Objects * Me * a blog post * your comment on a blog * Minecraft * a purple pen * a tweet * the Eagles

# Classes Types of "things"

# Classes * Person * Post * Comment * Player * Game * Pen * Message * Team

# Classes? * Me * a blog post * your comment on a blog post * Minecraft * a purple pen * a tweet * the Eagles

# I'm making: ## a Message Board App

# What classes should I have?

# My classes * Post * User

# Attributes Data that makes an object specific

# What attributes would Post have?

# Post * name * description * image * (id, created\_at, updated\_at)

# Types Tells Ruby what kind of data an attribute holds * string * integer * decimal * datetime

# Post Attribute Types? * name * description * image * (id, created\_at, updated\_at)

# Model = Class + Attributes + Types ( + methods)

# Make models with rails generate model ...

rails generate model post \
          name:string \
          description:string \
          image:string

Look in app/models/post.rb That's your model

class Post < ActiveRecord::Base
  attr_accessible :description, :image, :name
end

So destroy the model

rails destroy model post

And make a scaffold

rails generate scaffold post \
          name:string \
          description:string \
          image:string

# Scaffold = Model + Views + Controllers

run this

rake db:migrate

* start your sever * go to [http://localhost:3000/posts](http://localhost:3000/posts)

Try one of these: * [http://localhost:3000](http://localhost:3000) * [http://127.0.0.1:3000](http://127.0.0.1:3000)

# Try putting in some data

# How about a real image?

app/views/posts/show.html.erb before

after

# Views

<p>Mix html <%= with_ruby_code %></p>

# Try some things

Come from the controller app/controllers/posts_controller.rb

# Try it out, see what breaks!

# Homework Make a scaffold for your app, make some changes to the view files.