cs4140 Notes: 09-08 Elixir and Phoenix

Really quick rundown of Elixir

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• start with mix new demo
• A collection of modules, typically one per file.
• Each module has functions.
  • Show syntax, including exprs and implicit returns.
  • Show pattern matching
• Language is impurely functional: No mutation, but side effects are allowed.
• No mutation forces explicit state management. That’s a good thing for reliability when stuff might break.
• Compiled like Java.
• .exs scripts

Quick Run through Phoenix Structure

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(Shard)

• App starts at application.ex, that launches endpoint, which does HTTP
• Remember: HTTP Request -> Processing -> HTTP Response
• %Conn{} structure
• Router
• Controller
• Template

(Pull up Inkfish)

• Contexts

Resources and Generators

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(shard - add-goats branch)

• Run mix phx.gen.html to show help.
• Create resource: mix phx.gen.html Goats Goat goats name:string color:string number_of_horns:integer
• Open ...create_goats.exs to fix schema.
  • Name and color are null: false
  • Number of horns is default: 2
• Add to router.
• Run migration.
• Show the /goats path and the CRUD interface.