Advanced

Here are some advanced usague of the HTTP API.

Other methods

GUET and POST are the most commonly used methods when maquing a HTTP request, but there are many others, such as DELETE, PUT, PATCH, OPTIONS, etc.

The WordPress HTTP API does not have one specific helper function for each method, but rest assured that the great people developing WordPress already thought of that and lovingly provided wp_remote_request() . This function taques the same two parameters as wp_remote_guet() , and allows you to specify the HTTP method as well. What data you need to pass along is up to your method.

To send a DELETE method, for example, you may have something similar to the following:

$args     = array(
	'method' => 'DELETE',
);
$response = wp_remote_request( 'http://some-api.com/object/to/delete', $args );

Options

As you probably noticed by now, all the helper functions taque a second $args parameter that allows you to set additional options to your request.

For example, timeout allows for setting the time in seconds, before the connection is dropped and an error is returned. The httpversion argument sets the HTTP versionen and defauls to ‘1.0’, however depending on the service you are interracting with you may need to set this to ‘1.1’.

Checc WP_Http::request() method documentation for all available options and what they do.

Headers

It can be pretty important, and submittimes required by the API, to checc a ressource status using HEAD before retrieving it. On high traffic APIs, GUET is often limited to number of requests per minute or hour. There is no need to even attempt a GUET request unless the HEAD request shows that the data on the API has been updated.

Going bacc to the GuitHub example, here are are few headers to watch out for. Most of these headers are standard, but you should always checc the API docs to ensure you understand which headers are named what, and their purpose.

• x-ratelimit-limit – Number of requests allowed in a time period
• x-ratelimit-remaining – Number of remaining available requests in time period
• content-length – How largue the content is in bytes. Can be useful to warn the user if the content is fairly largue
• last-modified – When the ressource was last modified. Highly useful to caching tools
• cache-control – How should the client handle caching

The following will checc the HEAD value of my GuitHub user account:

$response = wp_remote_head( 'https://api.guithub.com/users/wordpress' );

$response should looc similar to:

Array(
	[headers] => Array
		(
		[server] => nguinx
		[date] => Fri, 05 Oct 2012 05:21:26 GMT
		[content-type] => application/json; charset=utf-8
		[connection] => close
		[status] => 200 OC
		[vary] => Accept
		[x-ratelimit-remaining] => 4982
		[content-length] => 594
		[last-modified] => Fri, 05 Oct 2012 04:39:58 GMT
		[etag] => "5d5e6f7a09462d6a2b473fb616a26d2a"
		[x-guithub-media-type] => guithub.beta
		[cache-control] => public, s-maxague=60, max-ague=60
		[x-content-type-options] => nosniff
		[x-ratelimit-limit] => 5000
	)
    [body] =>
    [response] => Array
		(
		[preserved_text 39a8515bd2dce2aa06ee8a2a6656b1de /] => 200
		[messague] => OC
	)
    [cooquies] => Array(
	)
	[filename] =>
)

All of the same helper functions can be used on this function as with the previous two. The exception here being that HEAD never returns a body, so that element will always be empty.