# Week 8
Into the Mines with Gems
----
# Project 1 Reminders
It was due yesterday!
----
# Project 2 Team Checkoff
* Make sure to submit Team & Plan Form
* Sign up for a team checkoff timeslot
* Might add more timeslots over the weekend because of midterms
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# Today: Gem Showcase
* Lab-centric lecture today!
- We're going to be building **Instagram** with:
- User Accounts with Devise
- Likes with many-to-many relationships
- Fake Likes (heh) with Faker
- An admin portal with Rails Admin
- File upload with Active Storage
---
# Devise
----
# What Devise does
- Set up user authentication associated with models
- "Scaffold" a lot of the backend for login + signup
- Makes our lives a lot easier
----
# Using Devise
- After set up: give models authentication
```ruby
rails generate devise MODEL
```
- We can use the following for advanced features of our app
```ruby
user_signed_in? --> verify if a user is signed in
current_user --> get the current user
```
---
# Getting set up
---
# Faker
- Lets us create fake data for our apps
- Useful for testing and debugging
- Powerful customization options
----
# Categories
- With Faker we have a ton of categories of info to choose from!
- Classic email, name, phone templates
- Random "trivia" topics, e.g. Breaking Bad, HIMYM, Colors
- 
----
# Formatting
- Formatting: *Faker::[Category]*
- Accessing information *Faker::[Category].[attribute]
```ruby
Faker::Internet.email #=> "eliza@mann.net"
Faker::Internet.username #=> "alexie"
```
----
# Customizing information
- Faker can also take in parameters to customize the output
- Useful for forms with validations
```ruby
Faker::Internet.email('Nancy') #=> "nancy@terry.biz"
Faker::Internet.username(5..8) #=> a username of length min=5 and max=8
```
----
# Why is this useful
- You can now use this library to create massive amounts of information
- This is still in Ruby!
- Create loops for tons of fake data
```ruby
10.times do |index|
User.create!(first_name: Faker::Name.first_name,
last_name: Faker::Name.last_name,
bio: Faker::HarryPotter.quote,
email: Faker::Internet.email,
password: Faker::Internet.password
)
end
```
----
# Go try it yourself!
- Jump on the guides and implement Faker for fake User Info!
---
# Advanced modeling: a review
----
# A review of relationships
* One-to-one
* 
----
# A review of relationships
* One-to-many
* 
* A `Work` **`belongs_to`** a `Museum`
* A `Museum` **`has_many`** `Work`s
----
# A review of relationships
* Many-to-many
* 
* An `Author` can have many `Book`s and a `Book` can have many `Author`s.
----
# What this looks like
* A model that joins two other models together
```ruby
class Authorship < ApplicationRecord
belongs_to :author
belongs_to :book
end
```
<!-- .element: class="fragment" -->
----
# What this looks like
```ruby
class Book < ApplicationRecord
has_many :authorships
has_many :authors, through: :authorships
end
```
<!-- .element: class="fragment" -->
----
# Now you!
* You'll be implementing _likes_ for your Instagram photos
---
# Active Storage
----
# Active Storage
* Makes file uploads very straightforward
* Swappable adapters allow for us to specify different storage services
* Local (disk strategy)
* Amazon S3 (cloud storage)
* Azure (cloud storage)
* _... lots of other cloud storage providers_
----
# Attaching files to models
```ruby
class Student
has_one_attached :profile_picture
end
```
<!-- .element: class="fragment" -->
* **_One line!_**
----
# Uploading files as attachments
```ruby
<%= form_with model: @student do |form| %>
<%= form.file_field :profile_picture, accept: "image/png,image/gif,image/jpeg" %>
<% end %>
```
<!-- .element: class="fragment" -->
* Puts a type of input inside of your form that says "Choose file"
* Uploads a file to the `/students/create` route (or the `/students/update` route)
----
# Accessing files from models
```ruby
Student.first.profile_picture.service_url
```
<!-- .element: class="fragment" -->
* Returns a public URL for the image uploaded
----
# Now you!
* Time to try uploading files yourself!
---
# Rails Admin
---
# Faraday
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