Marko HeijnenJanuary 14, 2012 at WordCamp Norway

Creating native apps with WordPress

Freelance developer

Mobile / WordPress

http://markoheijnen.com

info@markoheijnen.com

@markoheijnen

Marko Heijnen

History2006: Started with WordPress

2009: Started with iOS development

2010: First patch to WordPress ( 3.0 )

2011: Combined iOS development with WordPress

2012: First WordCamp presentation

Lets talk mobile

Mobile is the growing

There is a change youget involved with it

Native app vsWeb app/site

Native vs mobileBuild a native app when:

People are going to use it quite often ( daily basis )

Features that aren’t possible for web ( yet )

A lot of users request for it ( 10.000 > )

Customers really want an app

We need a native app

What does it mean for youYou need to communicate with another developer

Need to build an API that the developer can use

So you need to understand what a mobile developer wants

Need to build additional fields in WordPress for information that the mobile app can use

The API

API of the appWordPress for iOS uses XML-RPC

WordPress support it by default

Supports: Blogger API, metaWeblog API, and the Movable Type API

Where can you find it/xmlrpc.php

handles the request

/wp-includes/class-wp-xmlrpc.server.php

Registers all the default methods

Methods for testing/** * Test XMLRPC API by saying, "Hello!" to client. * * @since 1.5.0 * * @param array $args Method Parameters. * @return string */function sayHello($args) { return 'Hello!';}

/** * Test XMLRPC API by adding two numbers for client. * * @since 1.5.0 * * @param array $args Method Parameters. * @return int */function addTwoNumbers($args) { $number1 = $args[0]; $number2 = $args[1]; return $number1 + $number2;}

How to get recent postfunction mw_getRecentPosts($args) {

$this->escape($args);

$blog_ID = (int) $args[0]; $username = $args[1]; $password = $args[2]; if ( isset( $args[3] ) ) $query = array( 'numberposts' => absint( $args[3] ) ); else $query = array();

if ( !$user = $this->login($username, $password) ) return $this->error;

do_action('xmlrpc_call', 'metaWeblog.getRecentPosts');

How you can use it in your own way

Create your own methodsadd_filter( 'xmlrpc_methods', 'add_own_methods' );

function add_own_methods( $methods ) {$methods['own.my_method'] = 'own_my_method';

return $methods}

function own_my_method( $args ) {return $some_data

}

How does it look like

Request<?xml version="1.0"?><methodCall><methodName>metaWeblog.getRecentPosts</methodName><params><param><value><string></string></value></param><param><value><string>username</string></value></param><param><value><string>password</string></value></param></params></methodCall>

Response<?xml version="1.0"?><methodResponse> <params> <param> <value> <array><data> <value><struct> <member><name>dateCreated</name><value><dateTime.iso8601>20110904T18:15:26</dateTime.iso8601></value></member> <member><name>userid</name><value><string>1</string></value></member> <member><name>postid</name><value><string>1</string></value></member> <member><name>description</name><value><string>Welcome to &lt;a href=&quot;http://network.nginx.markoheijnen.com/&quot;&gt;WordPress Network Sites&lt;/a&gt;. This is your first post. Edit or delete it, then start blogging!</string></value></member> <member><name>title</name><value><string>Hello world!</string></value></member> <member><name>link</name><value><string>http://test.network.nginx.markoheijnen.com/2011/09/04/hello-world/</string></value></member> <member><name>permaLink</name><value><string>http://test.network.nginx.markoheijnen.com/2011/09/04/hello-world/</string></value></member> <member><name>categories</name><value><array><data> <value><string>Uncategorized</string></value></data></array></value></member> <member><name>mt_excerpt</name><value><string></string></value></member> <member><name>mt_text_more</name><value><string></string></value></member> <member><name>mt_allow_comments</name><value><int>1</int></value></member> <member><name>mt_allow_pings</name><value><int>1</int></value></member> <member><name>mt_keywords</name><value><string></string></value></member> <member><name>wp_slug</name><value><string>hello-world</string></value></member> <member><name>wp_password</name><value><string></string></value></member> <member><name>wp_author_id</name><value><string>1</string></value></member> <member><name>wp_author_display_name</name><value><string>marko</string></value></member> <member><name>date_created_gmt</name><value><dateTime.iso8601>20110904T18:15:26</dateTime.iso8601></value></member> <member><name>post_status</name><value><string>publish</string></value></member> <member><name>custom_fields</name><value><array><data></data></array></value></member> <member><name>wp_post_format</name><value><string>standard</string></value></member></struct></value></data></array> </value> </param> </params></methodResponse>

XML-RPCCritics of XML-RPC argue that RPC calls can be made with plain XML

XML-RPC uses about 4 times the number of bytes compared to plain XML

Need a lot of code on the app side

In the end the size of requests/responses do mather

Is this the best way orare there alternatives?

AlternativesJust XML instead of XML-RPC

Use JSON

What is JSONJavaScript Object Notation

Use JSON as alternative to XML

It is derived from the JavaScript scripting language

Lightweight text-based open standard

Why JSONLighter and faster than XML

JSON objects are typed

Array, object, string, number, boolean and null

Great libraries for mobile platformsiOS 5 does have native support for JSON

Easy to parse on mobile platforms

JSON Example{ "firstName" : "Marko", "lastName" : "Heijnen", "age" : 25, "address" : null, "newsletter" : false, "phoneNumber" : [ { "type" : "home", "number": "212 555-1234" }, { "type" : "fax", "number": "646 555-4567" } ] }

WordPress doesn’t have native support (yet)

Plugins you can useJSON RPC - http://wordpress.org/extend/plugins/wp-json-rpc-api/

JSON API - http://wordpress.org/extend/plugins/json-api/

WP RESTful - http://wordpress.org/extend/plugins/wp-restful/

Be aware that these plugins aren’t up to date

What do I use

JSON APIGreat to use because of the use of hooks

Good information on the plugin page

Simple backend interface

I use a modified version of it

Added consumer key/secret

Interface

How to implementfunction add_hello_controller( $controllers ) {

$controllers[] = 'hello';return $controllers;

}add_filter( 'json_api_controllers', 'add_hello_controller' );

function set_hello_controller_path() {return "/path/to/theme/hello.php";

}add_filter( 'json_api_hello_controller_path', 'set_hello_controller_path' );

How to implement<?phpclass JSON_API_Hello_Controller {

public function hello_world() {return array( "message" => "Hello, world" );

}}?>

Important to knowOnly return data that is needed

Return as less HTML as possible

Don’t change the feed without notifying the app developer

A call shouldn’t take to long, speed is everything

Cache the data if possible

Transients: http://codex.wordpress.org/Transients_API

Recap

How to managemobile content

Post typesAdd separate meta box for mobile content

Even the ability to overrule the title

Additional user capability, so not everyone can manage it

Maybe even create a special post type for mobile content

Special admin pageOnly for mobile configuration

Store settings

Store default pages for mobile like privacy disclaimer

Push notificationsCreate ability to send push notifications in a smart way

Add to posttype

Make a separate box on dashboard or admin page

You can handle the sending yourself

Or use for example the services of Urban Airship

Last wordWordPress is a CMS

Can be used in a lot of ways

Sometimes look further then the plugin section

Questions@markoheijnen / info@markoheijnen.com