extending wordpress as a pro

EXTENDING WORDPRESS AS A PROMarko HeijnenWordSesh December 2014

MARKO HEIJNEN

• Founder  of  CodeKitchen  

• Working  for  1&1  

• Lead  developer  of  GlotPress  

• Core  contributor  for  WordPress  

• Plugin  developer  

• Organizer  for  WordCamp  Belgradehttp://2015.belgrade.wordcamp.org/

WORDPRESS DEVELOPER

The Netherlands

TODAY’STOPICS

• Current ways to extend WordPress• Expect the unexpectable• Demo wpcentral.io

• Build for the future• Look at new technologies• Demo opensesh.org

• Questions

EXTENDING WORDPRESS

HOOKS

• Hooks are a way for one piece of code to interact with and modify another piece of code. They make up the foundation for how plugins and themes interact with WordPress Core, but they’re also used extensively by Core itself

• Two types of hooks: Actions and Filters

DROP-INS

Single site • advanced-cache.php• object-cache.php

• db.php• db-error.php

• install.php• maintenance.php

Multisite • sunrise.php• blog-deleted.php• blog-inactive.php• blog-suspended.php

PLUGGABLE FUNCTIONS

• These functions let you override certain core functions via plugins

• Pluggable functions are no longer being added to WordPress core

• All new functions instead use filters on their output to allow for similar overriding of their functionality

• See http://codex.wordpress.org/Pluggable_Functions

PLUGGABLE CLASSES

• Using a filter to replace the class that should be loaded like session_token_manager

• Be able to add your class to be loaded like wp_image_editors filter

EXPECT THE UNEXPECTABLECheck out: http://wpcentral.io/

WP CENTRALWHAT IS IT?

• Showing download history• Showing version usage history• List all locales and their current state• Showing contributors data (currently API only)

• Collects history of locale progress

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WP CENTRALHOW IT WORKS

• A lot of data handling by wp_remote_get• Scrapping profiles.WordPress.org to read data

• Bugs• Storing 0 values• Storing invalid data after failed wp_remote_get

requests• Not checking HTML output from

DOMDocument / DomXPath

WP CENTRAL CACHING STRATEGY

• Expensive query result caching• Cron job to retrieve download counts and version

usage• 24 hour cache per locale on request with a max of

5 locales per time• Using WP CLI to run it command line• Creating contributor data on request of the API

BUILD FOR THE FUTURE

BUILD FOR THE FUTURE

• When writing code, keep the changes you want to make in mind

• Future proofing is making sure you can easily add code/features without breaking existing functionality

• Make the code robust against unexpected problem situations allowing for graceful recovery or fail-fast, but do not write code for possible future uses.

LOOK AT NEW TECHNOLOGIEShttp://opensesh.org

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NODE.JS NODEJS.ORG

• JavaScript platform• Uses an event-driven, non-blocking I/O model• Lightweight and efficient• Ideal for real time application• Lot’s of modules you can use• Manage with NPM - https://www.npmjs.org

OPENSESH

OPENSESH.ORG

• A platform for conferences like WordSesh• Community driven project for the open source community• Node.js lets you push new sessions• This with the help of Socket.IO• When the session is over, you can simply replace it• Be able to use YouTube files as wait music

• Possible other ideas:• Create a hangout through WordPress• Have a personal schedule

THE SITE

MANAGING CHANNELS

BREAK TIME

CONNECTING TO WORDPRESS

• Node.js checks cookie data to indicate if user is logged in• Validates over JSON API and retrieve more user data• Returns a WP_User object• Has basic capability check support

BASIC CONFIGURATION

var config = {}, channels = [], clients = [];

config.port = 9000;config.application_host = ‘http://opensesh.com’;config.application_port = 80;

var app = require('http').createServer(handler), io = require('socket.io').listen(app), wordpress = require("wordpress-utils");

app.listen(config.port);wordpress.set_siteurl( config.application_host );

SERVER HANDLER (PART 1)

function handler(req, res) {if (req.url == "/status") {

res.writeHead( 200 );res.end();return;

}

var wp_user = wordpress.connect( req.headers.cookie, req.headers['x-token'] );if ( wp_user ) { // More code to come }

res.end();}

SOCKET CONNECTION

io.on('connection', function (socket) {clients[socket.id] = socket;socket.wp_user = wordpress.connect( socket.handshake.headers.cookie, socket.handshake.query.token );

socket.on('disconnect', function() {delete clients[socket.id]

});

var channel_id = parseInt(socket.handshake.query.channel);socket.emit('publish', { channel : channel_id, url :channels[ channel_id ].url });

});

SERVER HANDLER (PART 2)

wp_user.on('wp_connected', function ( data ) {if ( ! wp_user.can('manage_options') ) {

res.writeHead(403); res.end(); return;}var fullBody = ‘';

req.on('data', function(chunk) {fullBody += chunk.toString();

});

req.on('end', function() { // Access to JSON data }}

SERVER HANDLER (PART 3)

if (req.url == "/publish") {var json = JSON.parse(fullBody);if ( json.channel && json.url ) {

if ( ! channels[ json.channel ] ) {channels[ json.channel ] = {};

}channels[ json.channel ].url = json.url;io.sockets.emit( 'publish', { channel : json.channel, url : json.url } );

}else { res.writeHead(404); }

res.end();}

SERVER HANDLER (PART 4)

else if (req.url == "/channels") {res.writeHead( 200, {'Content-Type': ‘application/json’} );res.end( JSON.stringify(channels) );

}

res.end();

THANK YOU FOR LISTENING

QUESTIONS?

@markoheijnen - markoheijnen.com