Tweet
Tweet

Slide 1

Slide 1 text

Building a Resilient, API-driven Front-End with Elm Jeremy Fairbank @elpapapollo

Slide 2

Slide 2 text

@testdouble helps improves how the world build software. testdouble.com/agency

Slide 3

Slide 3 text

In beta now! bit.ly/programming-elm

Slide 4

Slide 4 text

const axios = require('axios') const fetchAlbum = name => axios.get(`/albums/${name}`) .then(({ data }) => data) const printAlbum = ({ name, artists }) => console.log(`${name} by ${artists.join(' - ')}`)

Slide 5

Slide 5 text

const axios = require('axios') const fetchAlbum = name => axios.get(`/albums/${name}`) .then(({ data }) => data) const printAlbum = ({ name, artists }) => console.log(`${name} by ${artists.join(' - ')}`)

Slide 6

Slide 6 text

const axios = require('axios') const fetchAlbum = name => axios.get(`/albums/${name}`) .then(({ data }) => data) const printAlbum = ({ name, artists }) => console.log(`${name} by ${artists.join(' - ')}`)

Slide 7

Slide 7 text

fetchAlbum('blue train') .then(printAlbum) // undefined by John Coltrane

Slide 8

Slide 8 text

fetchAlbum('blue train') .then(printAlbum) // undefined by John Coltrane

Slide 9

Slide 9 text

{ "title": "Blue Train", "artists": ["John Coltrane"] } const printAlbum = ({ name, artists }) => console.log(`${name} by ${artists.join(' - ')}`)

Slide 10

Slide 10 text

{ "title": "Blue Train", "artists": ["John Coltrane"] } const printAlbum = ({ name, artists }) => console.log(`${name} by ${artists.join(' - ')}`)

Slide 11

Slide 11 text

const printAlbum = ({ title, artists }) => console.log(`${title} by ${artists.join(' - ‘)}`) fetchAlbum('blue train') .then(printAlbum) // Blue Train by John Coltrane

Slide 12

Slide 12 text

const printAlbum = ({ title, artists }) => console.log(`${title} by ${artists.join(' - ‘)}`) fetchAlbum('blue train') .then(printAlbum) // Blue Train by John Coltrane

Slide 13

Slide 13 text

const printAlbum = ({ title, artists }) => console.log(`${title} by ${artists.join(' - ‘)}`) fetchAlbum('blue train') .then(printAlbum) // Blue Train by John Coltrane

Slide 14

Slide 14 text

fetchAlbum('blue trane') .then(printAlbum)

Slide 15

Slide 15 text

fetchAlbum('blue trane') .then(printAlbum)

Slide 16

Slide 16 text

fetchAlbum('blue trane') .then(printAlbum)

Slide 17

Slide 17 text

fetchAlbum('blue trane') .then(printAlbum) .catch(e => console.error(e))

Slide 18

Slide 18 text

No content

Slide 19

Slide 19 text

1. State management 2. Code organization 3. Data type guarantees 4. Null and undefined 5. JSON data contracts 6. Error handling 7. Primitive obsession Resiliency Problems

Slide 20

Slide 20 text

1. State management 2. Code organization 3. Data type guarantees 4. Null and undefined 5. JSON data contracts 6. Error handling 7. Primitive obsession Resiliency Problems

Slide 21

Slide 21 text

1. State management 2. Code organization 3. Data type guarantees 4. Null and undefined 5. JSON data contracts 6. Error handling 7. Primitive obsession Resiliency Problems

Slide 22

Slide 22 text

1. State management 2. Code organization 3. Data type guarantees 4. Null and undefined 5. JSON data contracts 6. Error handling 7. Primitive obsession Resiliency Problems

Slide 23

Slide 23 text

1. State management 2. Code organization 3. Data type guarantees 4. Null and undefined 5. JSON data contracts 6. Error handling 7. Primitive obsession Resiliency Problems

Slide 24

Slide 24 text

1. State management 2. Code organization 3. Data type guarantees 4. Null and undefined 5. JSON data contracts 6. Error handling 7. Primitive obsession Resiliency Problems

Slide 25

Slide 25 text

1. State management 2. Code organization 3. Data type guarantees 4. Null and undefined 5. JSON data contracts 6. Error handling 7. Primitive obsession Resiliency Problems

Slide 26

Slide 26 text

elm

Slide 27

Slide 27 text

Compiles to JavaScript

Slide 28

Slide 28 text

No runtime exceptions in practice.

Slide 29

Slide 29 text

No undefined is not a function

Slide 30

Slide 30 text

Back to our problems…

Slide 31

Slide 31 text

Update View Model Messages The Elm Architecture

Slide 32

Slide 32 text

Application State Model

Slide 33

Slide 33 text

Model Virtual DOM View UI as a Function

Slide 34

Slide 34 text

Messages Standardized application events

Slide 35

Slide 35 text

elm app model

Slide 36

Slide 36 text

elm app model Events Text Input Mouse Click Associate message with event

Slide 37

Slide 37 text

elm app model Events Text Input Mouse Click When event triggers (i.e. user clicks), deliver message

Slide 38

Slide 38 text

Update Model New Model Respond to messages and create new state

Slide 39

Slide 39 text

model Update View

Slide 40

Slide 40 text

model Update View

Slide 41

Slide 41 text

model Update View VDOM

Slide 42

Slide 42 text

model Update View VDOM

Slide 43

Slide 43 text

model Update View Select red color

Slide 44

Slide 44 text

model Update View Select red color

Slide 45

Slide 45 text

model Update View Select red color

Slide 46

Slide 46 text

model Update View

Slide 47

Slide 47 text

model Update View

Slide 48

Slide 48 text

model Update View

Slide 49

Slide 49 text

model Update View VDOM

Slide 50

Slide 50 text

model Update View VDOM

Slide 51

Slide 51 text

Demo

Slide 52

Slide 52 text

No content

Slide 53

Slide 53 text

The Elm Architecture 1. State management 2. Code organization

Slide 54

Slide 54 text

The Elm Architecture 1. State management 2. Code organization Static Types 3. Data type guarantees

Slide 55

Slide 55 text

The Elm Architecture 1. State management 2. Code organization Static Types 3. Data type guarantees Maybe 4. Null and undefined

Slide 56

Slide 56 text

The Elm Architecture 1. State management 2. Code organization Static Types 3. Data type guarantees Maybe 4. Null and undefined JSON Decoders 5. JSON data contracts

Slide 57

Slide 57 text

The Elm Architecture 1. State management 2. Code organization Static Types 3. Data type guarantees Maybe 4. Null and undefined JSON Decoders 5. JSON data contracts Result 6. Error handling

Slide 58

Slide 58 text

The Elm Architecture 1. State management 2. Code organization Static Types 3. Data type guarantees Maybe 4. Null and undefined JSON Decoders 5. JSON data contracts Result 6. Error handling Explicit State / Union Types 7. Primitive obsession

Slide 59

Slide 59 text

Thanks! Jeremy Fairbank @elpapapollo Slides: bit.ly/resilient-elm-codestock Code: bit.ly/resilient-elm-code-codestock Book: bit.ly/programming-elm