moodle-external-api-development

Moodle External API Development

This skill guides you through creating custom external web service APIs for Moodle LMS, following Moodle's external API framework and coding standards.

Detailed Guide

Read [the detailed guide](references/detailed-guide.md) before executing this skill. It retains the complete procedure and reference material. Treat its safety, prerequisites, and validation requirements as mandatory. For focused work, load the relevant sections; for end-to-end work, read the guide completely.

When to Use This Skill

• Creating custom web services for Moodle plugins
• Implementing REST/AJAX endpoints for course management
• Building APIs for quiz operations, user tracking, or reporting
• Exposing Moodle functionality to external applications
• Developing mobile app backends using Moodle

Examples from Real Implementation

Simple Read API (Get Quiz Attempts)

<?php
namespace local_userlog\external;

defined('MOODLE_INTERNAL') || die();
require_once("$CFG->libdir/externallib.php");

use external_api;
use external_function_parameters;
use external_single_structure;
use external_value;

class get_quiz_attempts extends external_api {
    public static function execute_parameters() {
        return new external_function_parameters([
            'userid' => new external_value(PARAM_INT, 'User ID'),
            'courseid' => new external_value(PARAM_INT, 'Course ID')
        ]);
    }

    public static function execute($userid, $courseid) {
        global $DB;

        self::validate_parameters(self::execute_parameters(), [
            'userid' => $userid,
            'courseid' => $courseid
        ]);

        $sql = "SELECT COUNT(*) AS quiz_attempts
                FROM {quiz_attempts} qa
                JOIN {quiz} q ON qa.quiz = q.id
                WHERE qa.userid = :userid AND q.course = :courseid";

        $attempts = $DB->get_field_sql($sql, [
            'userid' => $userid,
            'courseid' => $courseid
        ]);

        return ['quiz_attempts' => (int)$attempts];
    }

    public static function execute_returns() {
        return new external_single_structure([
            'quiz_attempts' => new external_value(PARAM_INT, 'Total number of quiz attempts')
        ]);
    }
}

Complex Write API (Create Quiz from Categories)

See attached create_quiz_from_categories.php for a comprehensive example including:

• Multiple database insertions
• Course module creation
• Quiz instance configuration
• Random question selection with tags
• Group-based access restrictions
• Extensive error logging
• Transaction management

Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.