TIY-Durham Rails August 2015

Week 8 - Overview

Students should be comfortable with the following at the end of this week:

Challenge: Primes

Human Learning:
- ON BOARD: Use short feedback loops
- Wife and dinner example
- Let’s use them here as we work on primes.
Runtimes and Primes
Computational Complexity (O(n), O(lg n), O(n^2), etc)
Memory Usage
Indices
- Example: Build Bank app with branches, clients, accounts, and expenses.
- Massive Seeds
- Database Indices
- Double indices
Transactions
Single-field search bar queries (ala Google)
AREL
Caching

Have fun!

Challenge: Double Loop Challenge

Random Topics
- Polymorphic associations
- AREL: to_dos = ToDo.arel_table followed by where(to_dos[:title].matches("%#{search}%").or(to_dos[:title].matches("Default")))
- Swap space
- CSV Writing
Background Processing
- Example: Bank Report Generation
- Review stacks vs. queues
- Queues in a Database Table
- DelayedJob
- ActiveJob
- Limited amount of information you can pass to a job.
Background Processing Steps
- Add gems delayed_job_active_record & daemons
- bundle install
- rails generate delayed_job:active_record
- rake db:migrate
- rails generate job JobName
- Somewhere in our code: JobName.perform_now(params[:something_important])
- In config/application.rb:
  - config.active_job.queue_adapter = :delayed_job
  - config.autoload_paths << Rails.root.join('app/jobs')
- bin/delayed_job start
- Somewhere in our code: JobName.perform_later(params[:something_important])
- When you are done coding: bin/delayed_job stop