Files

How to do Files on the web 10:25
We are working in the "public" folder
if we want to use something in the public folder, go to views/where you want it/html page you want it
<%= image_tag "name/png%>
all the files are accesible immediately on the root.
anything that's in public is available to anyone all the time
if there are images that should be seen only when logged in, you put them in the asset pipelime
public is where developers (not users) put images

files that users can upload:
file_field_tag, in views/where you want it/html
the form needs to be a mulitpart form 10:41
the form needs to take you to a path
now do work in the controller associated with the path

how to store the file.  if we put it int he db, it will make the db run slower.  instead we try to store it on a file system or the Cloud.
gem 'paperclip', "~> 4.2"   ~> Pessimistic versioning, means give me the version or higher as long as the first number is the same 4.5 is okay, but not 5.0, but not 4.1
paperclip puts things in the public folde.  to obfuscate has_attached_file :avatar, {:url => "/system/:hash...etc} 11:59
1. rails g migration AddFile
2. in model, has_attached_file :uploaded_file validates_attachment_content_type : uploaded_file, :content_type =>(regex)
3. in controller

if you do a form_for instead of a form_tag, its slightly different
use f.file_field
and add it to strong params

Amazon S3
EC2
S3: everything is S3 happens in regions.  creating buckets 11:50
getting your app to use a bucket, first add gem "aws-sdk", '~> 1.6'
tell your app how to use sdk 12:01
puts def S3_credentials in class Family < ActiveRecord:: 

12:13 what to put in config
make the bucket and wait 10 minutes for it to load up. 
clone, don't fork