json-image-resolver.php

<?php
/**
 * Plugin Name: JSON image resolver
 * Plugin URI: http://URI_Of_Page_Describing_Plugin_and_Updates
 * Description: Get one or more images from wordpress media library.
 * Version: 1.0.0
 * Author: João Beno Schreiner Junior
 * Author URI: http://joao.beno.net.br
 * License: GPLv2
 */

class Images_API_Endpoint{

    /** Hook WordPress
     * @return void
     */
    public function __construct(){
        add_filter('query_vars', array($this, 'add_query_vars'), 0);
        add_action('parse_request', array($this, 'receive_requests'), 0);
        add_action('init', array($this, 'add_endpoint'), 0);
    }
    /** Add public query vars
     * @param array $vars List of current public query vars
     * @return array $vars
     */
    public function add_query_vars($vars){
        $vars[] = 'jir';
        $vars[] = 'images';
        return $vars;
    }
    /** Add API Endpoint
     * @return void
     */
    public function add_endpoint(){
        add_rewrite_rule('^api/pugs/?([0-9]+)?/?','index.php?jir=1&images=$matches[1]','top');
        add_rewrite_rule('^api/pugs/?([0-9]+)?/?','index.php?jir=1&image=$matches[1]','top');
    }

    /** Receive Requests
     * If $_GET['jir'] is set, we reply
     * @return die if API request
     */
    public function receive_requests(){
        global $wp;
        if(isset($wp->query_vars['jir'])){
            $this->handle_request();
            exit;
        }
    }
    /** Handle Requests
     * @return void
     */
    protected function handle_request(){
        global $wp;

        $query_vars = $wp->query_vars;

        $imgs = $query_vars['images'];

        //If you want everything or just many things
        if ($imgs) {

            $param = $imgs;
            $imgs = $this->display_images_from_media_library($imgs);

            if($imgs)
                $this->send_response('ok', $imgs);
            else
                $this->send_response('Something went wrong with the all images function');
        }
    }
    /** Response Handler
     * This sends a JSON response to the browser
     */
    protected function send_response($msg, $json_img = ''){
        $response['status'] = $msg;

        if ($json_img) {
            $response['count'] = count($json_img);
            $response['images'] = $json_img;
        }

        header('Access-Control-Allow-Origin: *');
        header('Access-Control-Allow-Methods: POST, GET, OPTIONS');
        header('Access-Control-Allow-Headers: Origin, X-Requested-With, Content-Type, Accept, Access-Control-Allow-Origin, Access-Control-Allow-Methods');
        header('content-type: application/json; charset=utf-8');

        echo json_encode($response)."\n";

        exit;
    }

    protected function get_images_from_media_library($all_images) {
        $args = array(
            'post_type' => 'attachment',
            'post_mime_type' =>'image',
            'post_status' => 'inherit',
            'posts_per_page' => -1
        );
        $query_images = new WP_Query( $args );
        $images = array();
        foreach ( $query_images->posts as $image) {
            if ($all_images === "all") {
                $l_image = array();

                $l_image["id"]=$image->ID;
                $l_image["url"]=$image->guid;
                $l_image["description"]=$image->post_content;
                $l_image["title"]=$image->post_title;
                $l_image["caption"]=$image->post_excerpt;

                $images[]= $l_image;
            } else if (is_string($all_images) && strpos($all_images,",")) {
                $img_ids = explode(",",$all_images);
                $img_id = intval($image->ID);
                foreach ($img_ids as $iid) {
                    if ($img_id == intval($iid)) {
                        $l_image = array();

                        $l_image["id"]=$image->ID;
                        $l_image["url"]=$image->guid;
                        $l_image["description"]=$image->post_content;
                        $l_image["title"]=$image->post_title;
                        $l_image["caption"]=$image->post_excerpt;

                        $images[]= $l_image;
                    }
                }
            } else {
                $req_id = intval($all_images);
                $img_id = intval($image->ID);

                if ($img_id == $req_id) {
                    $l_image = array();

                    $l_image["id"]=$image->ID;
                    $l_image["url"]=$image->guid;
                    $l_image["description"]=$image->post_content;
                    $l_image["title"]=$image->post_title;
                    $l_image["caption"]=$image->post_excerpt;

                    $images[]= $l_image;
                }

            }
        }

        return $images;
    }

    protected function display_images_from_media_library($all_or_some = true) {

        $imgs = $this->get_images_from_media_library($all_or_some);
        $html = array();

        foreach($imgs as $img) {
            $html[]= $img;
        }

        return $html;
    }
}
new Images_API_Endpoint();