Architecture

Data Flow

Create Link

1. User submits form -> api::create() called.
2. Resolves code length from type (6/12/12).
3. If Unguessable, generates 16-char base62 code.
4. DB transaction: create link persistent (fires link_created event), attach tags.
5. Calls \core\shortlink::create_public_shortlink() for actual short URL.
6. If Unguessable, appends ?c=<code> to short URL.
7. Updates link record with final URL. Commit.

Visit Short Link

1. Moodle core shortlink system calls shortlink_handler::process_shortlink('url', $id).
2. Looks up link by ID.
3. If Unguessable, checks ?c= param matches stored code.
4. Fires link_redirected event.
5. Redirects to destination URL.

Delete Link

1. Route /{link}/delete -> confirmation -> sesskey check.
2. Deletes persistent (fires link_deleted event).
3. Redirects home.

Database

Table local_shortlinks:

Router

Uses Moodle’s router with PHP 8 attributes:

Shim route /redirect/delete?id=X bridges report builder actions (query params) to the path-param-based controller.

Events

All extend core\event\base:

Handler

shortlink_handler implements core\shortlink_handler_interface. Processes type url. Resolves link ID -> destination URL.

Observer

observers::user_deleted on core\event\user_deleted:

• Sets usermodified=0 for deleted user’s edits.
• Deletes all links owned by deleted user.

Report Builder

System report links with entity link:

• Columns: shorturl, destinationurl, timecreated.
• Filters: timecreated, userid, tags.
• Conditions: userid = current user.
• Actions: delete with modal confirmation.
• Favicons from DuckDuckGo (icons.duckduckgo.com/ip3/).

Tags

Tag area registered for local_shortlinks itemtype. Callback local_shortlinks_get_tagged_links() is a stub (not yet implemented).