c3s2 mostly done

Author: tomclose

_sessions/c3s1/7_homework.md

@@ -5,4 +5,41 @@ title: Homework
 {% exercise %}
 1. Finish the exercises from class.
 2. Do the [Codecademy Ruby track](http://www.codecademy.com/tracks/ruby) Sections 1 and 2.
+3. Get a [Heroku](https://www.heroku.com/) account and upload an ssh key (see below).
+{% endexercise %}
+
+### About Heroku
+
+[Heroku](https://www.heroku.com/) is a cloud-based web hosting solution, specifically designed for hosting web applications. It started out as a Rails host, but has since branched out into other frameworks (e.g. Sinatra, Node.js) and languages (e.g. Java, Python).
+
+They aim to completely manage your apps online infrastructure: you provide them with the code, they set it up and run it online. If you have a lot of users and want to scale your app up, they make it easy to allocate more resources so you can handle the increased traffic (for a price!). 
+
+### Setting up an account
+
+Before you deploy your app to heroku you need to create an account.
+
+{% exercise %}
+1. Sign up for an account at [Heroku](https://www.heroku.com/).
+2. After you log in, download and install the heroku toolbelt. (This will allow you to interact with heroku from the command line).
+{% endexercise %}
+
+### Setting up ssh with heroku
+
+The final part of the set up is to upload your ssh keys to Heroku. You might remember about ssh keys from the initial installation instructions: they're basically a way of identifying yourself to a server without typing in your password each time.
+
+The heroku toolbelt makes this very easy. On the command line (in any folder) type:
+
+    $ heroku keys:add
+
+You can check it worked by typing:
+
+    $ heroku keys
+
+It should list the ssh key that you just added.
+
+{% exercise %}
+Upload your ssh key to heroku by running
+
+    $ heroku keys:add
+
 {% endexercise %}

_sessions/c3s2/1_conditionals.md

@@ -0,0 +1,49 @@
+---
+title: Conditionals
+---
+
+So far we've just used ruby to evaluate simple expressions. Coding becomes a lot more interesting when you can use your code for simple logic tasks:
+
+{% highlight ruby %}
+if age >= 18
+  "Here's the vodka you wanted."
+else
+  "Move along please."
+end
+{% endhighlight %}
+
+If the code within the `if` block will only be run if the statement is true. If the statement is false, the code in the `else` block will be run instead.
+
+### Comparisons
+
+There are some basic comparisons that we will be useful when using if statments
+
+Symbol | Meaning
+---- | ----
+`==` | Is equal to
+`>`  | Greater than 
+`<`  | Less than
+`>=` | Greater than or equal to
+`<=` | Less than or equal to
+`!=` | Not equal to
+
+Comparisons evaluate to `true` or `false`.
+
+{% exercise %}
+Working with a partner, try out each of these comparisons in irb:
+{% highlight ruby %}
+4 == 5
+
+'five'.length > 5
+
+a = 20
+a <= 20
+
+true >= false
+
+'aardvark' < 'anteater'
+
+'we' != 'done yet'
+{% endhighlight %}
+{% endexercise %}
+

_sessions/c3s2/2_post_requests.md

@@ -0,0 +1,44 @@
+---
+title: Post requests revisited
+---
+
+Last time we looked at responding to `get` requests:
+
+{% highlight ruby %}
+get '/' do
+  "Hello there!"
+end
+{% endhighlight %}
+
+As you know from the Introduction to Web Programming course, `GET` is only one of several types of web requests. Another is the `POST` request, which is commonly used for submitting data from a web form.
+
+Suppose we have the following HTML form:
+
+{% highlight html %}
+<form method="post" action='/'>
+    <input type='text' name='user_name'>
+    <input type='text' name='user_age'>
+
+    <input type='submit'>
+</form>
+{% endhighlight %}
+
+The form will submit via a `POST` request to the root url, `/`. We can respond to this using the following sinatra block:
+
+{% highlight ruby %}
+post '/' do
+  name = params[:user_name]
+  age  = params[:user_age]
+
+  "Hello #{name}. You are #{age} years old."
+end
+{% endhighlight %}
+
+Note that, like the words matched in the url, the value of the `user_name` field is made available in the `params` hash. (If you want to have a look at the params hash you could put a `raise params.inspect` at the beginning of the method.)
+
+{% exercise %}
+1. **Fork** the repository [https://github.com/code61/sinatra_c3s2](https://github.com/code61/sinatra_c3s2) (using the fork button on the top right of the repository page on github).
+2. Clone down your fork of the repository onto your laptop.
+3. Open the `sinatra_c3s2` project in Sublime Text and have a read through `app.rb`. See if you can predict what the app will do.
+4. Run the app from the command line (`ruby app.rb`), to see if you were right.
+{% endexercise %}

_sessions/c3s2/3_deploying.md

@@ -0,0 +1,122 @@
+---
+title: App deployment
+---
+
+We're now going to look at how to get the Sinatra app online, a process known as *deployment*. We're going to deploy the app to [Heroku](heroku.com), which offers easy hosting for a variety of web frameworks - all you need to do is push up a git repository, and they take care of everything else!
+
+You should have set up a heroku account and uploaded your ssh keys for homework.
+
+### Preparation
+
+There are a few files `sinatra_c3s2` that we need if we're going to deploy the app to heroku:
+
+* config.ru
+* Gemfile
+
+`config.ru` contains the lines
+
+{% highlight ruby %}
+require './app.rb'
+run Sinatra::Application
+{% endhighlight %}
+
+These lines are to tell Heroku which file to find your application (`app.rb`) and how to run it (using Sinatra).
+
+The `Gemfile` is a way of specifying which gems your project uses. Heroku needs to know this so it knows which libraries it needs to run your app. The `Gemfile` is also really helpful way of remembering yourself which gems you need and is invaluable when working with others.
+
+{% highlight ruby %}
+# Gemfile
+
+source 'https://rubygems.org'
+
+gem 'sinatra'
+{% endhighlight %}
+
+Along with rubygems, ruby has a tool called bundler. Bundler helps you manage your ruby gems. If you run `bundle install` it will look in the `Gemfile` and install any gems that you don't already have.
+
+    $ bundle install
+
+ will also create a `Gemfile.lock` which specifies the exact version of the gems (e.g. the sinatra library) that you are using. This means that heroku (and anyone else you're collaborating with using git) now knows exactly which gems you are using and can pick to use the same versions. You need to check this in to your repository:
+
+    $ git add --all
+    $ git commit -m "Added Gemfile.lock"
+
+### Deploying to Heroku
+
+Once your app is prepared, the first thing you need to do is create a new empty heroku application. To do this you use the `heroku create` command:
+
+    $ heroku create
+    Creating arcane-gorge-2129... done, stack is cedar
+    http://arcane-gorge-2129.herokuapp.com/ | [email protected]:arcane-gorge-2129.git
+    Git remote heroku added
+
+You'll see that it created an app for you. In my case the app is called `arcane-gorge-2129` and can be found at http://arcane-gorge-2129.herokuapp.com. It also added a git remote for you. 
+
+    $ git remote -v
+    heroku  [email protected]:arcane-gorge-2129.git (fetch)
+    heroku  [email protected]:arcane-gorge-2129.git (push)
+    origin  [email protected]:code61/sinatra_project_1.git (fetch)
+    origin  [email protected]:code61/sinatra_project_1.git (push)
+
+### A bit about git remotes
+
+
+### Deploying
+
+You deploy your repository by pushing to this remote. Heroku will serve whatever is in the `master` branch. Here we push the `master` branch up to the `heroku` remote:
+
+    $ git push heroku master
+    Counting objects: 11, done.
+    Delta compression using up to 2 threads.
+    Compressing objects: 100% (6/6), done.
+    Writing objects: 100% (11/11), 1.08 KiB, done.
+    Total 11 (delta 1), reused 0 (delta 0)
+
+    -----> Ruby/Rack app detected
+    -----> Using Ruby version: ruby-1.9.3
+    -----> Installing dependencies using Bundler version 1.3.2
+           Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin --deployment
+           Fetching gem metadata from https://rubygems.org/..........
+           Fetching gem metadata from https://rubygems.org/..
+           Installing rack (1.5.2)
+           Installing rack-protection (1.5.0)
+           Installing tilt (1.4.1)
+           Installing sinatra (1.4.3)
+           Using bundler (1.3.2)
+           Your bundle is complete! It was installed into ./vendor/bundle
+           Cleaning up the bundler cache.
+    -----> Discovering process types
+           Procfile declares types     -> (none)
+           Default types for Ruby/Rack -> console, rake, web
+
+    -----> Compiled slug size: 25.0MB
+    -----> Launching... done, v3
+           http://arcane-gorge-2129.herokuapp.com deployed to Heroku
+
+    To [email protected]:arcane-gorge-2129.git
+     * [new branch]      master -> master
+
+After you push, heroku automatically updates the app and launches it for you. You can now see the app by visiting the url (in this case http://arcane-gorge-2129.herokuapp.com).
+
+{% exercise %}
+Deploy your `sinatra_c3s2` app to Heroku:
+1. Install your bundle to get a `Gemfile.lock`. In your `sintara_c3s2` directory run:
+
+        $ bundle install
+
+2. Add your work (and new `Gemfile.lock`) to your repository:
+
+        $ git add --all
+        $ git commit -m "Added Gemfile.lock"
+
+3. Create a new heroku app:
+
+        $ heroku create
+
+4. Push your work to Heroku
+
+        $ git push heroku master
+
+    (for subsequent updates you should be ok with just `git push heroku`).
+5. Visit the url that heroku provide, to check that your app is running!
+{% endexercise %}