Metadata

Moodle provides a variety of metadata which is used internally by Moodle, but which may also be useful in some developer tooling and integrations.

Plugin types and subsystems

The name and location on disk of every plugin type, and subsystem is described in lib/components.json.

Excerpt from lib/components.json

{
    "plugintypes": {
        "antivirus": "lib/antivirus",
        "availability": "availability/condition",
        "qtype": "question/type",
        "mod": "mod",
        // ...
    },
    "subsystems": {
        "access": null,
        "admin": "admin",
        // ...
    }
}

Subplugins

Any plugin which supports subplugins must describe its subplugin types by name and path in that plugins db/subplugins.json location.

This file requires that subplugins be specified as a set of key and value pairs where the key is the name of the subplugin type, and the value is the path to it.

• The name is the used as a prefix for all namespaces.
• The path is the path that the plugins exist within.

In the following example the subplugins used in mod_quiz are described.

The Quiz activity module is located in mod/quiz. It has two subplugin types, quiz, and quizaccess which are located in mod/quiz/report, and mod/quiz/accessrule respectively.

mod/quiz/db/subplugins.json

{
    "subplugintypes": {
        "quiz": "report",
        "quizaccess": "accessrule"
    },
    "plugintypes": {
        "quiz": "mod/quiz/report",
        "quizaccess": "mod/quiz/accessrule"
    }
}

Since 5.0

The list of subplugins should be detailed in the subplugintypes object which contains a list of the subplugins where the key is the component type, and the value is the path relative to the parent plugin.

For Moodle versions 4.5 and earlier the plugintypes object is used. The same keys must be used, but the values of subplugintypes are relative to the plugin's root directory, whilst the value of plugintypes are relative to the Moodle project root.

Plugins supporting Moodle 4.5 and earlier

If your plugin supports subplugins and is intended for use for both Moodle 5.0 and later, and Moodle 4.5 or earlier, you should specify both the subplugintypes and the plugintypes objects.

When both objects are specified the keys must match, and the paths relative to the plugin must also match.

APIs

Since 4.2

As described in the Namespacing section of the coding style, all Level 2 namespaces must be a Core API, or the word local.

Only those APIs meeting the following criterion are supported for this purpose:

• defined in /lib/apis.json; and
• having the allowedlevel2 flag set; and
• either:
  • having the same component as the API; or
  • having the allowedspread flag set.

Excerpt from lib/apis.json

{
    "access": {
        "component": "core_access",
        "allowedlevel2": true,
        "allowedspread": false
    },
    "admin": {
        "component": "core_admin",
        "allowedlevel2": false,
        "allowedspread": false
    },
    "adminpresets": {
        "component": "core_adminpresets",
        "allowedlevel2": true,
        "allowedspread": false
    },
    "analytics": {
        "component": "core_analytics",
        "allowedlevel2": true,
        "allowedspread": true
    },
    // ...
}

tip

A JSON schema for this file can be found at /lib/apis.schema.json.

Standard Plugins

Since 4.4

A list of the plugins which are shipped a standard Moodle installation, as well as the plugins which have recently been removed from this list is available in lib/plugins.json.

This list is in categorised under the categories standard, and deleted, and then by the plugin type, and finally the plugin name.

Excerpt from lib/plugins.json

{
    "standard": {
        "antivirus": [
            "clamav"
        ],
        "assignfeedback": [
            "comments",
            "editpdf",
            "file",
            "offline"
        ],
        "assignsubmission": [
            "comments",
            "file",
            "onlinetext"
        ],
        // ...
    },
    "deleted": {
        "assignment": [
            "offline",
            "online",
            "upload",
            "uploadsingle"
        ],
        "auth": [
            "fc",
            "imap",
            "nntp",
            "pam",
            "pop3",
            "radius"
        ],
        // ...
    }
}

tip

A JSON schema for this file can be found at /lib/plugins.schema.json.