wordcamp birmingham 2016 - wp api, what is it good for? absolutely everything!

WP API what is it good for

Absolutely Everything

Slides available httpscirclecubecomdoes-wordpress

WordCamp Birmingham - 29 October 2016

IntroductionsEvan Mullins

Lead Web Developer

Brown Bag Marketing

circlecube

circlecubecom

WordPress user since 2006

Full-time web developer since 2007

API

An (API) is a set of

subroutine definitions protocols and tools for building software and applications A

good API makes it easier to develop a program by providing all the building blocks

which are then put together by the programmer

An API is best thought of as a contract provided by one piece of software to another

And growing

October 2016 hits 16000 apis

REST

It describes how one system can communicate state with another One example would

be the state of a product (its name description etc) represented as JSON The

generalised idea of state is termed a resource

JSON

is a lightweight data-interchange format

It is easy for humans to read and write It is easy for machines to parse and generate It

is a text format that is completely language independent but uses conventions that are

familiar to programmers These properties make JSON an ideal data-interchange

language

JSON is built on two structures

A collection of namevalue pairs (object)

An ordered list of values (array)

WP REST API

WordPress is moving towards becoming a fully-fledged application framework and we need new APIs

This project was born to create an easy-to-use easy-to-understand and well-tested framework for creating these APIs plus creating APIs for core

This plugin provides an easy to use REST API available via HTTP

Grab your sitersquos data in simple JSON format including users posts taxonomies and more

Retrieving or updating data is as simple as sending a HTTP request

Want to get your sitersquos posts

Simply send a GET request to

Update user with ID 4

Send a POST request to

wp-jsonwpv2users4

Get all posts with the search term ldquoawesomerdquo

GET

wp-jsonwpv2postssearch=awesome

Itrsquos that easy

The API exposes a simple yet easy interface to WP Query the posts API post meta API users API revisions API and many more

Chances are if you can do it with WordPress WP API will let you do it

Whatrsquos with the V2

A little historyRyan McCue started development on an API and then proposed a WordPress JSON

REST API Project for GSOC in April 2013 (when WordPress was on version 35)

Version 20 of the plugin rebuilt the first with lessons learned The infrastructure

merged into WordPress core in version 44 (December 2015)

A little historyAlthough it was proposed for 45 the

merge was delayed in order to build it out

with more endpoints The REST API is

slated for inclusion in 47 after

considerable discussion and planning

Authentication and further integration

with core will be a focus of 48

Until 47 when this is officially merged into

core (December-ish 2016) wersquoll need to

install the REST API feature Plugin

It about to be realDid you catch that

The REST API merging into

WordPress core

In 47

Thatrsquos a big deal

WPRESTAPIPlugin(for now)

Resources

httpsgithubcomWP-APIWP-API

Resources

httpv2wp-apiorg

Slack Channel

Get Started Today Post 471 Install the plugin

2 Play

a yoursitecomwp-jsonwpv2

1 Install the plugin

2 Play

a yoursitecomwp-jsonwpv2

InstallThePlugin

Need to do this

until the API

endpoints are

merged into core

NutshellSo in a nutshell rather than getting your content or data via a

webpage as part of a website with php html css and javascript

you can use whatever you want and retrieve your data via the

API Yoursquoll get json data that is compact and fast to transfer and

then you can do endless things with it Create an app load it into

another website analyze it as datahellip itrsquos a great step for

WordPress and a great step to continuing democratizing the web

ToolsPostman -

HTTP or

API client

Also REST Easy for Firefox or httpie for the command line

Back to WordPressThe pluginAPI exposes your data in JSON format in the following content types

Posts

Pages

Media

Custom Post Types

Post Meta

Revisions

Comments

Terms

Users

Routes EndpointsEndpoints are functions available through the API and are simply urls This can be

things like retrieving the API index updating a post or deleting a comment Endpoints

perform a specific function taking some number of parameters and return data to the

client

A route is the ldquonamerdquo you use to access endpoints used in the URL A route can have

multiple endpoints associated with it and which is used depends on the HTTP verb

Routes Endpoints ExampleWith the URL

The ldquorouterdquo is (the route doesnrsquot include wp-json because wp-json

is the base path for the API itself)

This route has 3 endpoints

triggers a get_item method returning the post data to the client

triggers an update_item method taking the data to update and returning the

updated post data

triggers a delete_item method returning the now-deleted post data to the

client

get list of latest posts

retrieve a single post

GET - to read data

Standard arguments as yoursquod expect and more

etc

GET

PUT - to create or update data create post

update existing post

DELETE - to trash

Authentication

AuthenticationWhen and why would you need this

Internal wp code (plugintheme development) use cookies

External code (using wp api as service) use oauth

AuthenticationIf you are building a theme or a plugin and want to access

the API of the same site where the theme or plugin will be

yoursquoll want to authenticate with a cookie

Use a nonce (WordPress security token) to connect to a

local API if your theme or plugin wants to connect to the

API of the site itrsquos on via ajax