Modern JavaScript and REST

The language of the web got a lot better

Who are we?

Dušan Mlađenović

Developer/consultant at Bouvet

Developer with huge passion for functional programming, javascript and related languages.

�Contact at: dusan.mladenovic@bouvet.no

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Marius Kalvø

Developer/consultant at Bouvet

Interest in backend and devOps, delivery of software

Contact at: marius.kalvo@bouvet.no

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Vil Vite WIFI

SSID: VIS-gjest

Password: visdet2019

Our sponsors

Bouvet is a Norwegian consultant firm with over 1000 employees, assisting businesses in all areas of IT, communication, and business development.

Customers (in Bergen) includes Equinor, TV2, Statkraft, Sparebanken Vest, and Bergen kommune, among others.

http://www.bouvet.no/�https://www.bouvet.no/bouvet-deler

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VIS bidrar til at samfunnsutfordringer løses effektivt, og at kunnskap og ideer kommer raskt til nytte. Forskere, gründere og etablert næringsliv kommer til VIS med utfordringer og ideer som vi videreutvikler sammen.

https://www.visinnovasjon.no

Invite: tinyurl.com/nerdschoolslack

Nerdschool resources

• All presentations are public on Google Docs
• http://tinyurl.com/nerdschoolslides
• Git repository pr workshop
• https://github.com/nerdschoolbergen/
• Static web page with info (how to come prepared)
• http://nerdschoolbergen.github.io/home
• Meetup for signup and feedback
• http://www.meetup.com/Bergen-Nerdschool/

ECMAScript 20XX

ECMA-what?

• ECMAScript 5 (old) vs ECMAScript 20XX (new)
• Main new(ish) features:
• let / const
• template strings
• default parameters
• arrow functions
• modules
• classes
• For...of loop
• Spread operator
• Promises
• async / await

let / const

• var is scoped to the nearest function block, which can make variables awkward to handle in inner scopes
• let is scoped to the nearest enclosing block, which can be smaller than the function block. This makes scoping of let variables easier to handle

Template strings

• Easier way to handle strings with dynamic data

Default parameters

Now possible to define a default value for a parameter if it’s not set explicitly

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Arrow functions

• Syntax sugar for writing functions
• Can return directly

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Modules

• A file is a module
• Importing and exporting
• Encapsulation
• Before ES6: no modules (just chaos), then AMD (RequireJS) and CommonJS(node)

Classes

• Syntactical sugar for �JavaScript’s prototype interface
• It’s just a function
• Constructor
• Methods
• Properties (get/set)

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Classes continued

• Static methods
• Easier to handle inheritance

Asynchronous operations

• Better APIs for writing async code
• async / await does not replace Promises but use Promises

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How to use all these awesome features?

• Modern browsers and modern JS runtimes support most of the new features
• If a JS runtime does not support the features you are using you can
• Transpile - Use a tool to rewrite your code so that the JS runner understands it
• Polyfill - A unit of code that fills the gap of missing native support for some functionality

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REST

What is REST?

• Representational State Transfer
• Access resources by their URLs
• Leverage HTTP to represent operations on a resource
• GET http://localhost/book
• GET http://localhost/book/1
• POST http://localhost/book , body: { “title”: “Nerdschool” }
• PUT http://localhost/book/1, body { “title”: “loohcsdreN” }
• DELETE http://localhost/book/1

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Why REST?

• It’s native to the web - no fuzz!
• All serious languages supports it - no need to learn a “new way”
• Excellent for connecting systems cross-platform or cross-language
• Easy to learn
• Easy to get up and running fast

Working with resources

• A resource is an entity we base REST operations around. E.x.: book
• The URL reflects our resource
• The HTTP verb reflects what kind of operation we want
• The data for the operation is in the request URL, header, and/or body.

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Assignments

Exercises

• https://github.com/nerdschoolbergen/modern-javascript-and-rest
• If requested, we can go through the solution for tasks you want at 19:40-ish

Next meetup

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Risk-based testing

8/10/2019

http://www.meetup.com/Bergen-Nerdschool/

Remember to sign up! (It’s really important!)

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