Create User using JSON API

I’ve never worked with that plugin and a new JSON Rest API will maybe be included in core with one of the future versions. So far it’s as well available as plugin.

To make it short: There currently seems to only be three kinds of Controllers in that plugin

1. Core
2. Posts
3. Respond

But there’s a section on the main plugin page that explains how to extend the plugin and how to develop JSON API Controllers. So It’s actually just a slightly modified copypaste from what you could have read in the very excellent and detailed plugin page !

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

Your controller is now available as hello, and exposes one hello_world method.

Next, activate your controller from the WordPress admin interface, available from the menu under Settings > JSON API. You can either click on the link to your hello_world method from the admin interface or enter it manually. It should have the form: http://www.example.org/api/hello/hello_world/?dev=1 or http://www.example.org/?json=hello.hello_world&dev=1 (note the use of the dev argument to enable human-readable output). You should get the following output:

{
    "status": "ok",
    "message": "Hello, world"
}

Using query vars

To customize the behavior of your controller, you will want to make use of the global $json_api->query object. Add the following method to your controller:

public function hello_person()
{
    global $json_api;
    $name = $json_api->query->name;
    return array(
        "message" => "Hello, $name."
    );
}

Now append the name query var to the method call:

http://www.example.org/api/hello/hello_world/?dev=1&name=Alice

…or…

http://www.example.org/?json=hello.hello_world&dev=1&name=Alice.

The result will be:

{
    "status": "ok",
    "message": "Hello, Alice"
}

To make your controller visible from an external plugin or theme directory you will need to use two filters: json_api_controllers and json_api_[controller]_controller_path. Just create a custom plugin that holds your controller and add the following code:

<?php
/** Plugin Name: (#109019) Custom Hello JSON API Controller */

function add_hello_controller( $controllers )
{
    $controllers[] = 'hello';
    return $controllers;
}
add_filter( 'json_api_controllers', 'add_hello_controller' );

function set_hello_controller_path()
{
    return plugin_dir_path( __FILE__ )."helloController.php";
}
add_filter( 'json_api_hello_controller_path', 'set_hello_controller_path' );

// >> Controller goes here <<

// A more organized file structure might work as well, but it's ok
// to stuff everything in a single file if used as mu-plugin.

You can use any sort of WP public API functions in your Controller. Still JSON API has a middle ware layer as well. Example:

global $json_api;
$posts = $json_api->introspector->get_posts( array(
    'meta_key'   => $json_api->query->key,
    'meta_value' => $json_api->query->value

) );