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 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

Illustrative Implementation Fragments

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;

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

        $context = \context_course::instance($params['courseid']);
        self::validate_context($context);
        require_capability('mod/quiz:viewreports', $context);
        // Instructor-report endpoint; add group/quiz-specific visibility restrictions as needed.

        $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' => $params['userid'],
            'courseid' => $params['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)

The referenced create_quiz_from_categories.php is not bundled. Do not claim it was read, executed or transaction-tested. Use the installed Moodle release's activity/question APIs with context/capability checks, group visibility, bounded input and rollback tests; direct insertion fragments in the guide are historical schema illustrations, not a complete quiz builder. Use least-privilege test roles and synthetic learner data, never production admin tokens in shell arguments.

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.