moodle-local_ai_content

Utility and service plugin for AI-related content handling in Moodle.

local_ai_content is designed as a reusable foundation for other plugins that need to process content for AI workflows. It provides shared service interfaces, centralized processing logic and common operational features (cache, logging, privacy handling), so consuming plugins do not need to reimplement the same infrastructure.

At the moment, the plugin ships with one production-ready service: text extraction from Moodle files.

Positioning

• Service plugin for other plugins - not a standalone end-user feature plugin.
• AI content utility layer - central place for content preprocessing capabilities used by AI-enabled Moodle plugins.

Currently available service

Text extraction service

The text extraction service reads textual content from different file types (plain text, images, PDFs, office documents) using a configurable AI backend and Moodle document conversion capabilities where required.

Key behavior:

• Unified extraction API via \local_ai_content\extractor.
• Pluggable backend selection (local_ai_manager ITT purpose or Moodle core AI subsystem, based on plugin settings).
• Content-hash caching to avoid repeated expensive extraction runs.
• Admin test page to validate extraction behavior for current site config.

Typical integration

Consumer plugins resolve the service via DI and call the extractor:

$extractor = \core\di::get(\local_ai_content\extractor::class);
$text = $extractor->extract_text_from_file($file, $contextid, $userid, 'your_component');

The your_component value should identify the caller component for traceability in logging/auditing.

Supported file types (text extraction)

• Text formats - direct read, no AI required: text/plain, text/html, text/xml, text/markdown, text/rtf, text/csv.
• Images (PNG, JPEG, WebP, GIF) - via AI image-to-text when supported by the configured backend.
• PDF - via backend-native handling or PDF page rendering (pdftoppm) plus image-to-text; converter fallback if available.
• Office documents - via enabled core_files converters. Candidate extensions include DOC, DOCX, RTF, ODT, XLS, XLSX, ODS, PPT, PPTX, ODP, HTML, CSV.
• Connector-native types - additional MIME types declared by the configured backend.

Availability depends on backend capabilities and server converter setup. Use the admin test page or extractor::get_supported_extensions() to inspect the current effective support.

Error contract (text extraction)

extract_text_from_file() returns an empty string only when content is truly empty/unextractable as text, and throws moodle_exception for actual processing failures.

Callers should therefore:

• handle empty string as "no text content" (not an error), and
• use try/catch for operational failures.

Representative error strings include:

• error_unsupportedfiletype
• error_ainotavailable
• error_airequestfailed
• error_ittnotsupported
• error_conversionfailed
• error_pdfrenderingunavailable

Configuration

Site administration -> Plugins -> Local plugins -> AI Content Manager:

• AI backend - backend used by extraction paths that require AI.
• Cache lifetime (days) - retention for extracted text cache entries.
• Test text extraction - upload and inspect extraction behavior.

Capability for test page access:

• local/ai_content:testextraction

PDF rendering recommendation

For reliable PDF extraction quality, install Poppler pdftoppm.

Debian/Ubuntu:

sudo apt-get install poppler-utils

RHEL/CentOS/Fedora:

sudo dnf install poppler-utils

Configure in:

Site administration -> Server -> System paths -> Path to pdftoppm

This maps to $CFG->pathtopdftoppm. If not configured, pdftoppm is expected in system PATH.

Roadmap direction

local_ai_content is intended to host additional reusable AI content services in the future (for example, normalization, chunking, metadata enrichment, or other preprocessing utilities), while keeping a stable service-plugin contract for consuming plugins.

License

2026, ISB Bayern

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.