moodle-mod_hvp/classes/content_user_data.php

<?php

/**
 * The mod_hvp content user data.
 *
 * @package    mod_hvp
 * @since      Moodle 2.7
 * @copyright  2016 Joubel AS
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

namespace mod_hvp;

/**
 * Class content_user_data handles user data and corresponding db operations.
 *
 * @package mod_hvp
 */
class content_user_data {

    /**
     * Retrieves ajax parameters for content and update or delete
     * user data depending on params.
     *
     * @throws \coding_exception
     */
    public static function handle_ajax() {
        // Query String Parameters
        $content_id = required_param('content_id', PARAM_INT);
        $data_id = required_param('data_type', PARAM_ALPHA);
        $sub_content_id = required_param('sub_content_id', PARAM_INT);

        // Form Data
        $data = optional_param('data', NULL, PARAM_RAW);
        $pre_load = optional_param('preload', NULL, PARAM_INT);
        $invalidate = optional_param('invalidate', NULL, PARAM_INT);

        if ($content_id === NULL || $data_id === NULL || $sub_content_id === NULL ||
            $data === NULL || $invalidate === NULL || $pre_load === NULL) {
            return; // Missing parameters
        }

        if (!\H5PCore::validToken('contentuserdata', filter_input(INPUT_POST, 'token'))) {
          \H5PCore::ajaxError(get_string('invalidtoken', 'hvp'));
          exit;
        }

        // Delete user data
        if ($data === '0') {
            self::delete_user_data($content_id, $sub_content_id, $data_id);
        }
        else {
            // Save user data
            self::save_user_data($content_id, $sub_content_id, $data_id, $pre_load, $invalidate, $data);
        }

        \H5PCore::ajaxSuccess();
        exit;
    }

    /**
     * Save user data for specific content in database.
     *
     * @param $content_id
     * @param $sub_content_id
     * @param $data_id
     * @param $pre_load
     * @param $invalidate
     * @param $data
     */
    public static function save_user_data($content_id, $sub_content_id, $data_id, $pre_load, $invalidate, $data) {
        global $DB, $USER;

        // Determine if we should update or insert
        $update = $DB->get_record('hvp_content_user_data', array(
                'user_id' => $USER->id,
                'hvp_id' => $content_id,
                'sub_content_id' => $sub_content_id,
                'data_id' => $data_id
            )
        );

        // Wash values to ensure 0 or 1.
        $pre_load = $pre_load === '0' ? 0 : 1;
        $invalidate = $invalidate === '0' ? 0 : 1;

        // New data to be inserted
        $new_data = (object)array(
            'user_id' => $USER->id,
            'hvp_id' => $content_id,
            'sub_content_id' => $sub_content_id,
            'data_id' => $data_id,
            'data' => $data,
            'preloaded' => $pre_load,
            'delete_on_content_change' => $invalidate
        );

        // Does not exist
        if ($update === FALSE) {
            // Insert new data
            $DB->insert_record('hvp_content_user_data', $new_data);
        }
        else {
            // Get old data id
            $new_data->id = $update->id;

            // Update old data
            $DB->update_record('hvp_content_user_data', $new_data);
        }
    }

    /**
     * Delete user data with specific content from database
     *
     * @param $content_id
     * @param $sub_content_id
     * @param $data_id
     */
    public static function delete_user_data($content_id, $sub_content_id, $data_id) {
        global $DB, $USER;

        $DB->delete_records('hvp_content_user_data', array(
            'user_id' => $USER->id,
            'hvp_id' => $content_id,
            'sub_content_id' => $sub_content_id,
            'data_id' => $data_id
        ));
    }

    /**
     * Load user data for specific content
     *
     * @param $content_id
     * @return mixed User data for specific content if found, else NULL
     */
    public static function load_user_data($content_id) {
        global $DB;

        $result = $DB->get_record('hvp_content_user_data', array(
            'hvp_id' => $content_id
        ));

        return $result ? $result->data : NULL;
    }
}