kai-jacobsen/kontentblocks

<?php

namespace Kontentblocks\Backend\DataProvider;

/**
 * Class PostMetaDataProvider
 * Wrapper to WordPress native post meta functions
 * This class has been stripped down to the essentials during development and has only the least necessary
 * methods available for the plugin to work.
 * @package Kontentblocks\Backend\Post
 * @since 0.1.0
 */
class PostMetaDataProvider implements DataProviderInterface
{

    /**
     * Post ID to get meta from
     * @var int
     * @since 0.1.0
     */
    protected $postId;

    /**
     * 'cached' meta data
     * @var array
     * @since 0.1.0
     */
    protected $meta = array();

    /**
     * Class constructor
     *
     * @param $storageId
     *
     * @throws \Exception
     * @since 0.1.0
     */
    public function __construct($storageId)
    {
        if (!isset($storageId) || $storageId === 0) {
            throw new \Exception('a valid post id must be provided');
        }

        add_action('updated_post_meta', function ($metaId, $objectId, $metaKey, $metaValue) {
            if ($objectId === $this->postId) {
                clean_post_cache($this->postId);
                $this->reset();
            }
        }, 10, 4);

        $this->postId = $storageId;

        $this->reset();

    }

    /**
     * Makes sure the object stays in line with actual meta data
     * Should be called after any meta data modification
     * @return self
     * @since 0.1.0
     */
    public function reset()
    {
        $this->getPostCustom();
        return $this;
    }

    /**
     * Gets all post meta for current post.
     * Setup the Object.
     * @todo account for multiple keys
     * @return self
     * @since 0.1.0
     */
    private function getPostCustom()
    {
        $meta = get_post_custom($this->postId);
        if (!empty($meta) && is_array($meta)) {
            $this->meta = array_map(
                function ($entry) {
                    return maybe_unserialize($entry[0]);
                }, $meta);
        } else {
            $this->meta = array();
        }

        return $this;

    }

    /**
     * Getter for objects post id
     * @return int
     * @since 0.1.0
     */
    public function getPostId()
    {
        return $this->postId;
    }

    /**
     * Updates existing keys or creates new ones
     * Wrapper to ::update() since the plugin does not make use of multiple
     * equal keys (yet)
     *
     * @param $key
     * @param $value
     *
     * @since 0.1.0
     */
    public function add($key, $value)
    {
        $this->update($key, $value);
    }

    /**
     * Simple wrapper to update_post_meta
     *
     * @param $key
     * @param $value
     *
     * @since 0.1.0
     * @return mixed
     */
    public function update($key, $value)
    {
        $this->meta[$key] = $value;
        $parent_id = wp_is_post_revision($this->postId);
        if ($parent_id) {
            return update_metadata('post', $this->postId, $key, $value);
        }

        return update_post_meta($this->postId, $key, $value);
    }

    /**
     * Wrapper to retrieve data by key from post meta
     *
     * @param id string Key
     *
     * @return mixed|null
     * @since 0.1.0
     */
    public function get($key)
    {
        if (!empty($this->meta[$key])) {
            return $this->meta[$key];
        } else {
            return null;
        }
    }

    /**
     * Delete meta by key
     *
     * @param $key
     *
     * @return bool
     * @since 0.1.0
     */
    public function delete($key)
    {
        unset($this->meta[$key]);
        return delete_post_meta($this->postId, $key);
    }

    /**
     * Returns all meta data for this postId
     * @return array
     * @since 0.1.0
     */
    public function getAll()
    {
        return $this->meta;
    }

    /**
     * @return bool
     */
    public function addSlashes()
    {
        return true;
    }
}