Slide 1

Slide 1 text

SERVING DATA FROM BROWSERS

Slide 2

Slide 2 text

I’M BEN (@BENJAMINBENBEN)

Slide 3

Slide 3 text

No content

Slide 4

Slide 4 text

No content

Slide 5

Slide 5 text

THE INTERNET BUTTON

Slide 6

Slide 6 text

No content

Slide 7

Slide 7 text

No content

Slide 8

Slide 8 text

SERVING DATA FROM BROWSERS

Slide 9

Slide 9 text

SPOILER ALERT: SERVICE WORKERS

Slide 10

Slide 10 text

! THANKS, PHIL

Slide 11

Slide 11 text

WHAT WE’RE TALKING ABOUT: MY DATA ➡ ‘ AS A USER, I WANT TO HAVE MY DATA IN A CSV DOCUMENT

Slide 12

Slide 12 text

LASTFM RUNKEEPER

Slide 13

Slide 13 text

BENFOXALL/LAST-FM-TO-CSV BENFOXALL/RUNKEEPER-TO-CSV

Slide 14

Slide 14 text

HOW DO WE GET OUR DATA? (RUNKEEPER)

Slide 15

Slide 15 text

ATTEMPT 1

Slide 16

Slide 16 text

DOWNLOAD IT

Slide 17

Slide 17 text

No content

Slide 18

Slide 18 text

No content

Slide 19

Slide 19 text

! > Job Done > Works Offline

Slide 20

Slide 20 text

! > No format control > Functionality might change/disappear

Slide 21

Slide 21 text

ATTEMPT 2

Slide 22

Slide 22 text

WRITE A SCRIPT

Slide 23

Slide 23 text

export BEARER=MY_TOKEN_FROM_THE_CONSOLE curl https://api.runkeeper.com/fitnessActivities?pageSize=100 -H "Authorization: Bearer $BEARER" > page1.json curl https://api.runkeeper.com/fitnessActivities?pageSize=100&page=2 -H "Authorization: Bearer $BEARER" > page2.json curl https://api.runkeeper.com/fitnessActivities?pageSize=100&page=3 -H "Authorization: Bearer $BEARER" > page3.json curl https://api.runkeeper.com/fitnessActivities?pageSize=100&page=4 -H "Authorization: Bearer $BEARER" > page4.json curl https://api.runkeeper.com/fitnessActivities?pageSize=100&page=5 -H "Authorization: Bearer $BEARER" > page5.json jq '.items' page*.json | grep uri | sed 's/^.*"\///g' | sed 's/"//g' > urls.txt mkdir fitnessActivities while read p; do curl https://api.runkeeper.com/$p -H "Authorization: Bearer $BEARER" > $p.json done < urls.txt

Slide 24

Slide 24 text

No content

Slide 25

Slide 25 text

! > format choices > sharable > offline

Slide 26

Slide 26 text

! > Inaccessible

Slide 27

Slide 27 text

ATTEMPT 3

Slide 28

Slide 28 text

MAKE A WEB SERVICE

Slide 29

Slide 29 text

No content

Slide 30

Slide 30 text

No content

Slide 31

Slide 31 text

! > Accessible to more people > Works offline*

Slide 32

Slide 32 text

! > Non-trivial backend > Handling sensitive data > Waiting for processing

Slide 33

Slide 33 text

ATTEMPT 4

Slide 34

Slide 34 text

GO CLIENT-SIDE

Slide 35

Slide 35 text

No content

Slide 36

Slide 36 text

No content

Slide 37

Slide 37 text

No content

Slide 38

Slide 38 text

! > Data stored locally > Available instantly

Slide 39

Slide 39 text

! IT MIGHT NOT TOTALLY WORK ALL THE TIME

Slide 40

Slide 40 text

COOL

Slide 41

Slide 41 text

TODO (IN BROWSER): 1. Request from data source 2. Process data (➡ csv) 3. Serve to user

Slide 42

Slide 42 text

1. REQUEST > 2. PROCESS > 3. SERVE (LASTFM)

Slide 43

Slide 43 text

1. REQUEST

Slide 44

Slide 44 text

A ONE FUNCTION JAVASCRIPT API const lastFM = params => fetch("http://ws.audioscrobbler.com/2.0/?"+ "method=user.getrecenttracks&format=json"+ "&api_key=974a5ebc077564f72bd639d122479d4b&"+ params) .then(r => r.json())

Slide 45

Slide 45 text

WHAT REQUESTS DO WE NEED FOR A USER? const requestsForUser = username => lastFM(`user=${username}`) .then(_find_number_of_pages_) .then(number => Array.from({length: number - 1}, (_,i) => `user=${username}&page=${i+1}` ) )

Slide 46

Slide 46 text

WHAT REQUESTS DO WE NEED FOR A USER? requestsForUser("benjaminf") // resolves to: [ "user=benjaminf&page=1", "user=benjaminf&page=2", "user=benjaminf&page=3", "user=benjaminf&page=4", … ]

Slide 47

Slide 47 text

MAKE REQUESTS const dataForUser = username => requestsForUser(username) .then(requests => Promise.all( requests.map(lastFM) ) )

Slide 48

Slide 48 text

2. PROCESS

Slide 49

Slide 49 text

JSON ➡ CSV

Slide 50

Slide 50 text

THE WAY YOU SHOULD PROBABLY DO THIS… papaparse.com/docs#json-to-csv

Slide 51

Slide 51 text

…ANOTHER WAY // pull out a row of keys const row = (keys, obj) => keys.map(k => obj[k]) // create a csv row from an array const csv = array => array.map(item => typeof(item) === 'string' ? item.replace(/[\",]/g,'') : item ).join(',') + "\n" /* csv(row(["a","b","n"],{b: "\"bar\"", c: "yeah", a: "foo", n: 42}) > "foo,bar,42" */

Slide 52

Slide 52 text

const process = response => response.tracks.map(track => csv(track, ["artist", "name"]) )

Slide 53

Slide 53 text

Promise.all( requests.map( r => lastFM(r).then(process) ) ) .then(parts => parts.join(""))

Slide 54

Slide 54 text

3. SERVE

Slide 55

Slide 55 text

DATA URIS

Slide 56

Slide 56 text

data:[][;base64],

Slide 57

Slide 57 text

data:text/html,

Hello World

Slide 58

Slide 58 text

data:text/csv,a,b,c%0A1,2,3

Slide 59

Slide 59 text

ALL TOGETHER const process = response => response.tracks.map(track => csv(track, ["artist", "name"]) ) const dataForUser = username => requestsForUser(username) .then(requests => Promise.all( requests.map(lastFM) ) .then(parts => parts.join("")) )

Slide 60

Slide 60 text

ALL TOGETHER dataForUser("benjaminf") .then( csv => { const link = document.createElement("a") link.href = _to_data_uri(csv, "text/csv") link.innerText = "Download csv" document.body.appendChild(link) })

Slide 61

Slide 61 text

URGH .then(csv => { _to_data_uri(csv, "text/csv")

Slide 62

Slide 62 text

BLOBS

Slide 63

Slide 63 text

new Blob(parts [,options])

Slide 64

Slide 64 text

const blob = new Blob(["a,b,c\n", "d,e,f"],{type : "text/csv"}) const url = window.URL.createObjectURL(blob) // > "blob:…/41f8da4d-…-dbdc62106843" const a = document.createElement("a") a.textContent = a.href = url document.body.appendChild(a)

Slide 65

Slide 65 text

const process = response => response.tracks.map(track => csv(track, ["artist", "name"]) ) const dataForUser = username => requestsForUser(username) .then(requests => Promise.all( requests.map( req => lastFM(req).then(process) ) ) .then(parts => parts.join("")) )

Slide 66

Slide 66 text

const process = response => new Blob(response.tracks.map(track => csv(track, ["artist", "name"]) )) const dataForUser = username => requestsForUser(username) .then(requests => Promise.all( requests.map( req => lastFM(req).then(process) ) ) .then(parts => new Blob(parts, {type : "text/csv"})) )

Slide 67

Slide 67 text

dataForUser("benjaminf") .then( csv => { const link = document.createElement("a") link.href = _to_data_uri(csv, "text/csv") link.innerText = "Download csv" document.body.appendChild(link) })

Slide 68

Slide 68 text

dataForUser("benjaminf") .then( csv => { const link = document.createElement("a") link.href = URL.createObjectURL(csv) link.innerText = "Download csv" document.body.appendChild(link) })

Slide 69

Slide 69 text

1. REQUEST > 2. PROCESS > 3. SERVE

Slide 70

Slide 70 text

benjaminbenben.com/lastfm-to-csv/

Slide 71

Slide 71 text

COOL, BUT… 1. DATA LOSS ON EXIT 2. NO URLS 3. DOESN’T WORK OFFLINE

Slide 72

Slide 72 text

! SERVICE WORKERS ! (& INDEXEDDB)

Slide 73

Slide 73 text

1. REQUEST > 2 SAVE > 3. PROCESS > 4. CACHE > 5. SERVE* (RUNKEEPER)

Slide 74

Slide 74 text

1. REQUEST

Slide 75

Slide 75 text

PRETTY MUCH THE SAME FRONTEND

Slide 76

Slide 76 text

No content

Slide 77

Slide 77 text

2. SAVE !

Slide 78

Slide 78 text

IndexedDB (via Dexie) var db = new Dexie("Runkeeper") db.version(1).stores({ activities: "&uri" }) db.open(); // on request fetch('data' + uri, { credentials: 'include' }) .then(res => res.json() ) .then(data => db.activities.put(data))

Slide 79

Slide 79 text

No content

Slide 80

Slide 80 text

3. PROCESS

Slide 81

Slide 81 text

SUMMARY RESPONSE function summaryResponse() { console.time('build summary') var keys = ['uri', 'duration', 'type', 'start_time', 'total_distance', 'climb', 'total_calories']; var rows = [keys]; return db .activities .reverse() .each(function(activity){ rows.push( row(keys, activity) ) }) .then(function(){ console.timeEnd('build summary'); var data = new Blob(rows.map(function(row){ return csv(row) + '\n'; })); return new Response( data, { headers: { 'Content-Type': 'text/csv' } }); }) }

Slide 82

Slide 82 text

4. CACHE ! "

Slide 83

Slide 83 text

Slide 84

Slide 84 text

5. SERVE ! " !

Slide 85

Slide 85 text

SERVE SW/SUMMARY.CSV self.addEventListener('fetch', event => if(event.request.url.match(/sw\/summary\.csv$/)) respond(event, summaryResponse) )

Slide 86

Slide 86 text

WIN: MULTIPLE VIEWS self.addEventListener('fetch', event => { if(event.request.url.match(/sw\/summary\.csv$/)) respond(event, summaryResponse) if(event.request.url.match(/sw\/distances\.csv$/)) respond(event, distancesResponse) if(event.request.url.match(/sw\/paths\.csv$/)) respond(event, pathsResponse) if(event.request.url.match(/sw\/geo\.json$/)) respond(event, geoJSONResponse) if(event.request.url.match(/sw\/geo\.simple\.json$/)) respond(event, geoJSONResponseSimple) if(event.request.url.match(/sw\/binary\.path\.b$/)) respond(event, binaryPathResponse) })

Slide 87

Slide 87 text

! > Offline > Super Fast > Super great

Slide 88

Slide 88 text

DEMO

Slide 89

Slide 89 text

GITHUB: BENFOXALL/LAST-FM-TO-CSV BENFOXALL/RUNKEEPER-TO-CSV

Slide 90

Slide 90 text

ONLINE HTTP://BENJAMINBENBEN.COM/ LASTFM-TO-CSV/ HTTPS://RUNKEEPER-TO- CSV.HEROKUAPP.COM/

Slide 91

Slide 91 text

$ $ PROFIT! $ $

Slide 92

Slide 92 text

THANKS! @BENJAMINBENBEN