In this presentation I've shown how WordPress can be used as application platform to power mobile applications.

1. Mobile hybrid development with WordPress
Saturday November 24th, 2012
Bologna, Italy

2. WordPress.com Reader
• WordPress.com has introduced a blog reader feature
that’s a cross between Google Reader and reader
apps like Flipboard. Through it you can keep track of
blogs from WordPress.com, but also other places.

3. WordPress.com Reader
• The reader displays all the posts across
all the blogs you follow in the order they
were published, with the most recent
content appearing at the top. You’ll see
an excerpt of the introduction to each
post, the first image in the post, and
thumbnails of any other images that the
post contains.

4. WordPress.com Reader

5. WordPress.com Reader
• A user can add any blog to the Reader
by tapping the “Follow” button in the
top admin bar while viewing the blog.

6. Introducing the mobile Reader
• Read posts from blogs you’re following on
WordPress.com right in the mobile apps,
with the addition of social actions, such as
‘like’, ‘reblog’, ‘in-line commenting’, and
more.
• We wanted to add this new feature on all of
our mobile apps (Android, iOS, BlackBerry,
Windows Phone), trying to reuse the same
codebase as much as possible.

7. Requirements
• The content should be available as soon as
the user clicks on the button. No lags, no
long loading time. (If your app takes too long
loading data, the user will probably switch to
another task).
• Access device native features such as
sounds, native pull-to-refresh, blog
preferences stored in the app.
• Native or Hybrid ? -> We tried the Hybrid way

8. Hybrid Mobile Apps
• A hybrid app is a native, downloadable app, that runs
all or some of its UI in an embedded browser
component.
• HTML / CSS / JavaScript.
• Hybrid apps can access device features such as file-
system, cameras and geolocation services.
• Frameworks, such as the open source project
‘Apache Cordova’, make the development of hybrid
apps portable across devices, and allow developer to
access native device features from one common JS
API.

9. Loading the Reader
• Clients authenticate on startup and keep track of the WP
auth cookie. ( An alternative way is to use the
WordPress.com login form and the redirect_to parameter,
but it’s slower ).
• The target of the redirect ( The URL of the Reader ) is
something like https://wordpress.com/reader/mobile/v2/
• We’ve added a filter on ‘page_template’, and the server
outputs a simple HTML5 page.
• The home page is a template that loads the required CSS
and JS files.
• Ajax calls to load the content of the reader. Those calls
will start when the home page is fully loaded on the client.

10. [
Example of server response
{
"fp_bg_image" : "http://s2.wp.com/imgpress?w=310&url=http%3A%2F%2Faphs.worldnomads.com
%2FOffTheBeatenPath%2F22448%2FiStock_000003676011Small.jpg&unsharpmask=80,0.5,3",
"avatar" : "http://en.wordpress.com/wp-content/themes/h4/i/mobile/subs-rss-mobile.png?
cached",
"author_name" : "Tim",
"author_avatar" : "http://1.gravatar.com/avatar/a4797cc25c5fe8922fc81c7d16e17bd8?s=64&d=http
%3A%2F%2F0.gravatar.com%2Fblavatar%2F0ef9c8d9ca53dd718d",
"title" : "I Donu2019t Enjoy the Ride",
"content" : "<p><img class="alignright" title="Road Trip" alt="" src="http://s0.wp.com/
imgpress?url=http%3A%2F%2Faphs.worldnomads.com%2FOffTheB>....",
"excerpt" : "<div class="full">..../div>...",
"post_id" : 185,
"guid" : "http://narrativeodyssey.com/?p=185",
"permalink" : "http://narrativeodyssey.com/2012/11/17/i-dont-enjoy-the-ride/",
"blog_id" : "35445524",
"blog" : "my narrative odyssey",
"blogurl" : "http://narrativeodyssey.wordpress.com",
"ts" : 1353217713,
"comment_count" : 0,
"pluralized_comment" : "Comments",
"ago" : "1d",
...
"follow_url" : "http://wordpress.com/following?b=00&amp;_wpnonce=not_in_the_house_XXdd5a200",
"unfollow_url" : "http://wordpress.com/following?b=00&amp;unsub=1&amp;_wpnonce=not_in_the_hous",
"following" : 0
},

11. How it looks on different devices
The same experience on
Android and iOS. A little bit
different on BB.

12. How it looks on different devices
BlackBerry with Keyboard iPhone4

13. How it looks on different devices : Topics
Selector
BlackBerry with Keyboard iPhone4

14. How it looks on different devices : Comment
Form
BlackBerry with Keyboard iPhone4

15. JS Libraries used
• FitVids.js - A lightweight, easy-to-use
jQuery plugin for fluid width video
embeds.
• {{ mustache }} - Templating
• Two internal libraries for UA detection
and capabilities detection.

16. Communication between JS and Native code
• We’ve written a “bridge” that simplies the
communication between the JS layer and
the native code (and vice versa).
• The bridge also adds some security
checks to prevent malicious pages from
executing native methods.

17. Issues found
• Excessive stuttering when scrolling the posts list with
images on it (Old versions of Android).
• On the iPhone4 there were issues scrolling the lists
due to missing optimizations for the UIWebView, and
the absence of the Nitro JS Engine.
• We did a lot of optimizations, but the scrolling is fast
on iPhone 4S, not on the iPhone4.
• BlackBerry 7 browser is very slow at rendering
complex pages.
• Windows Phone 7 doesn’t support HTML5 so we
skipped that platform for now.

18. Performance Improvements (1)
CACHE:
# JS
/wp-includes/js/jquery/jquery.js
..
# CSS
/wp-content/themes/nomoreplasticthree/mobile/v2/reader.css
..
# images from the CSS
/wp-content/themes/nomoreplasticthree/i/mobile/v2/read.png
/wp-content/themes/nomoreplasticthree/i/mobile/v2/read@2x.png
...
# All other content accessed over the Network
NETWORK:
/wp-admin/admin-ajax.php*
*
http://*
https://*

19. Performance Improvements (2)
• Use of localStorage to store the JSON response(s),
and make them available without accessing the net.
• JS time-diff to update the content without reloading it
from the network.
• Images are replaced with a smaller version server-
side. Full version will be downloaded later, on
demand, with a simple JS code. (This is possible
thanks to the .COM ImagePress API).
http://s0.wp.com/imgpress?url=http%3A%2F
%2Fdigilander.libero.it%2Frondine_spensierata
%2FUomoVetriRottiMare.jpg&h=150

20. The Future: REST API + Native
• REST API opens access to posts,
comments, follow, like and more.
• http://developer.wordpress.com
• Available on WordPress.com, and on
Jetpack powered sites.
• Should be available in WordPress Core
in the future.

21. WordPress mobile apps
WordPress Mobile
http://make.wordpress.org/mobile
App specific development blogs with links to code testing info:
• WordPress for Android
http://dev.android.wordpress.org/
• WordPress for BlackBerry
http://dev.blackberry.wordpress.org/
• WordPress for iOS
http://iphonedev.wordpress.org/
• WordPress for Windows Phone
http://wpwindowsphonedev.wordpress.org/

22. Thanks ! Questions ?
Danilo Ercoli
Mobile Wrangler
http://daniloercoli.wordpress.com
http://twitter.com/daniloercoli