Introduction to Programming in Ruby on Rails

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Learn to Program with Ruby

Leaders: JoshCo & Jack

See the app running on Heroku

to start with my running example

Github repo with the running code:

Perform the following steps:

git clone people

bundle install

rake db:migrate

rails server

browse to http://localhost:3000

drink the rails kool-aid

doing it yourself

$ = command line prompt code italics = edits inside a text editor or IDE program comments about what/why this is important and does stuff = not defined yet

$ git commit -m “foo”

Rails is easier to teach and you don’t have to go into as many details as other languages

contact list:

model view controller - rails works with a model view controller paradigm

Contact List has a number of fields - name, email, etc.

the model is the table of people

the view ends up on the interface of the web browser (add, edit, view contacts)

Controller is the http server that will use the model and the view to know what to do

edit and add records in the model table

People is the name of the app

very easy with rails to create a new framework for your app

$ rails new people

- creates base app

$ rails generate scaffold person

- creates the model 

$ rails generate scaffold person name:string email:string phone:string

- create base html files, reasonable looking view, create controller which will answer requests, creates a migration that is basically database entries

Rails knows how to pluralize things, so said people instead of persons (most of the time)

Many languages (especially PHP) there are a bazillion options/ways to do the same thing and rails is very strict with following conventions

$ rake db:migrate

- creates the migration file, table

rake = ruby version of make command

IDE - rubymine highly recommended and you can find the project folder to view the files that rails created

$ rails server

in browser go to: localhost:3000 /people - see a list of people

want to know about your gemfile - open the gemfile inside rubymine/IDE

Troubleshooting initial install:

comment out the gem ‘jquery-rails’ line (~23 in example) | # in front of line to comment out in rails

# gem 'jquery-rails'

and try to move gem ‘json-pure’,

                         gem ‘json-ruby’ 

if you have trouble initially

in browser: click on “new person” and enter fields to add a new person

Rails lets you get to so much with so much less coding

marriage hero started in march of this year with others helping and in less than a year had an event list, geocoded, and a map and almost as simple as adding the geocode to the gemfile and magic happens

after you create a new person, you can go and edit views and wraps

open config folder and find routes.db and open in editor type

root :to -> ‘people#index’  

save and check out the browser again

app folder, views, layout, application.html.erb

2 types of views (layout displayed at all times and per object views)

the application.html.erb

in body

Welcome to NPDev

save and now it’s on every page

(cause it’s a banner) banners are the part that frame your application

look at controllers, people_controller.rb

.def index @people - person.all @foo - ‘barrrr’

respond_to do (asking for the format like html, .json)

if you want a rest API for your app, it’s already done for you with Rails

update and create render forms and you can find the “success messages”

edit apps\views\people\index.erb

go to bottom above link -> person <%= @foo %>

another example: <% if @foo==‘bar’ %> - for if statements/comparisons

create a git repository, add the files to the repository, do a commit/initial check-in


group :production do gem ‘pg’ end

group :development do

gem ‘sqlite3’

end This puts the production database that will be on heroku as postgres and the development DB as SQL lite (which is local and a smaller db)

$ heroku apps:create npdev people $ git remote -v $ git status $ git commit -m ‘db change’ $ git push heroku master

git pushes to heroku, but acts like a repository but with a lot of hooks that can detect rails, and can fire up the app assuming no errors

manually need to tell it to do a migration to create the database

you’ll have all these migrations for all models you created, and you can rollback if you screw up

$ heroku run rake db:migrate

creates the tables

then, once it’s done you should be able to view it live on heroku/browser link

$ heroku --tail logs

watch in command line as it spins up

an intended convention that keeps your local database not sync’d with your online database (production) without apps

you can later on do complicated queries when you advance and maintain a database sync’d where you pull down the database locally for development and testing