This document discusses integrating external APIs into WordPress sites. It covers what APIs are, how they can be used to get and send data, and how to authenticate with APIs. It provides examples of using the WordPress HTTP API to make requests and examples of handling responses. It also discusses best practices like caching responses to avoid hitting rate limits and using WordPress APIs to help with caching.

1. Integrating External APIs

2. Freelance WordPress Developer 8+ years
Owner and Lead Developer at
PhotographyBlogSites.com
martythornley.com @martythornley
A Little About Me

3. Application Program Interface
Allows programs
to communicate
with each other
What is an API?
Get information
Send information

4. What do APIs do?
TwitterDisplay Tweets
Yelp
Display Listings &
Search
Amazon
List & Sell
Products
Your Website or App

5. What do APIs do?
TwitterPost Tweets
Your Website or App
Facebook
Send new status,
images, location
InstagramCreate Likes

6. https://codex.wordpress.org/WordPress_APIs
Internal WordPress APIs
Makes plugins possible
Makes talking to the database easier
Makes theme customization possible
Makes communicating with external API’s easier

7. HTTP API
Database API
Options API
Transients API
Metadata API
Plugin API
https://codex.wordpress.org/WordPress_APIs
Internal WordPress APIs
Dashboard Widgets API
File Header API
Filesystem API
Quicktags API
Rewrite API
Shortcode API
Theme Modification API
Theme Customization API
Widgets API
XML-RPC WordPress API
Settings API

8. How To Use APIs
Endpoint
Authentication
Methods
Arguments
Response
URL where API ‘lives’
May be public or require authentication
Possible ways of using the API
Specify what you want it to do
What it sends back

9. Authenticate with APIs
None
Basic
OAuth
Not typical
Encoded username:password combo
or an API KEY
Complicated

10. WordPress HTTP API
wp_remote_get
wp_remote_post
Retrieve URL using GET HTTP method
Retrieve URL using POST HTTP method
https://codex.wordpress.org/HTTP_API
$response = wp_remote_get( $url , $args );

11. Response from an API
Array
(
[headers] => Array
(
[content-type] => text/html; charset=utf-8
[date] => Wed, 25 Mar 2015 03:43:43 GMT
[server] => Mashape/5.0.6
[via] => 1.1 vegur
[x-powered-by] => Express
[content-length] => 51
[connection] => Close
)
[body] => THE STUFF WE WANT
[response] => Array
(
[code] => 200
[message] => OK
)
[cookies] => Array
(
)
[filename] =>
)

12. Response from an API
Array
(
[headers] => Array
(
[content-type] => text/html; charset=utf-8
[date] => Wed, 25 Mar 2015 03:43:43 GMT
[server] => Mashape/5.0.6
[via] => 1.1 vegur
[x-powered-by] => Express
[content-length] => 51
[connection] => Close
)
[body] => THE STUFF WE WANT
[response] => Array
(
[code] => 200
[message] => OK
)
[cookies] => Array
(
)
[filename] =>
)

13. WordPress HTTP API
https://codex.wordpress.org/HTTP_API
$headers = wp_remote_retrieve_headers( $response );
$headers = wp_remote_retrieve_header( $response );
$code = wp_remote_retrieve_response_code( $response );
$message = wp_remote_retrieve_response_message( $response );
$body = wp_remote_retrieve_body( $response );

14. Error Checking Response
$response = wp_remote_get( $url , $args );
$code = wp_remote_retrieve_code( $response );
if ( $code == ‘200’ ) {
$body = wp_remote_retrieve_body( $response );
}

15. What Format is Response?
string
xml
json
$array = json_decode( $body );
$json = json_encode( $array );

16. Caching Response
Play nice with the API / Save your rate limits
Don’t wait on external services when possible
Use WordPress API’s to help
Options
Transients
WP_Object_Cache
Meta
Save to db
Save to db with time limit
Cache in memory
User / Post Meta

17. Caching Response
set_transient( ‘my_transient_name’ , $body , 30 );
get_transient( ‘my_transient_name’ );
delete_transient( ‘my_transient_name’ );
set_site_transient( ‘my_transient_name’ , $body , 30 );
get_site_transient( ‘my_transient_name’ );
delete_site_transient( ‘my_transient_name’ );
https://codex.wordpress.org/Transients_API

18. Caching Response
$body = get_transient( ‘my_transient_name’ );
if ( $body !== false ) {
$response = wp_remote_get( $url , $args );
$code = wp_remote_retrieve_code( $response );
if ( $code == ‘200’ ) {
$body = wp_remote_retrieve_body( $response );
set_transient( ‘my_transient_name’ , $body , 30 );
}
}

19. Example API Plugin
Yoda Speak
http://github.org/martythornley/yoda-speak

20. Where to find APIs
http://www.programmableweb.com/
https://www.mashape.com
http://apis.io/

21. Questions
martythornley@gmail.com
martythornley.com
photographyblogsites.com