---
title: groupeventsource - X4 schema type
summary: groupeventsource: An event-source object group expression. The group must exist but may be empty and its membership may change. The check attribute does not apply to group sources.
section: reference
kind: guide
status: reference
updated: 2026-10-27
tags: ["XSD","schema","types"]
sources: ["https://wiki.egosoft.com/X4%20Foundations%20Wiki/Modding%20Support/","https://www.w3.org/TR/xmlschema11-2/"]
---
## Meaning

groupeventsource: An event-source object group expression. The group must exist but may be empty and its membership may change. The check attribute does not apply to group sources.

An XSD type constrains XML, rather than declaring a Lua return or the payload type of event.param. A valid schema value does not prove a successful game effect.

## Schema structure

`libraries/common.xsd`

| Property | Value |
| --- | --- |
| Construction | `restriction` |
| Base type | [`expression`](wiki:schema-expression-b8bc0e4f) |

restriction narrows a base type; union accepts one of its branches; list describes whitespace-separated items. Enumeration values in one restriction are alternatives. Pattern syntax is XML Schema regex, not Lua patterns or JavaScript RegExp. Constraints inherited from the base type still apply.

## Example and result

```xml
<event_object_collided group="$WatchedShips" />
```

**What happens:** The condition observes sources in the pre-existing MD group $WatchedShips; this is not an arbitrary Lua table.

Object and group variables must already exist in the correct MD / AI context. These are learning fragments, not a complete runnable mission.

## Used by

| Element | Attribute | Schema |
| --- | --- | --- |
| [`event_build_added`](wiki:api-mdevent-event-build-added-e177e0e5) | `group` | `libraries/common.xsd` |
| [`event_build_cancelled`](wiki:api-mdevent-event-build-cancelled-ab070aea) | `group` | `libraries/common.xsd` |
| [`event_build_finished`](wiki:api-mdevent-event-build-finished-7629377f) | `group` | `libraries/common.xsd` |
| [`event_character_animation_finished`](wiki:api-mdevent-event-character-animation-finished-8f6be6a0) | `group` | `libraries/common.xsd` |
| [`event_character_animation_started`](wiki:api-mdevent-event-character-animation-started-32dbc6a4) | `group` | `libraries/common.xsd` |
| [`event_countermeasure_launched`](wiki:api-mdevent-event-countermeasure-launched-aa0600f9) | `group` | `libraries/common.xsd` |
| [`event_long_range_scan_sent`](wiki:api-mdevent-event-long-range-scan-sent-e232eb0a) | `group` | `libraries/common.xsd` |
| [`event_object_changed_true_owner`](wiki:api-mdevent-event-object-changed-true-owner-d4bd10fc) | `group` | `libraries/common.xsd` |
| [`event_object_collided`](wiki:api-mdevent-event-object-collided-ea144cb6) | `group` | `libraries/common.xsd` |
| [`event_object_destroyed`](wiki:api-mdevent-event-object-destroyed-31ba2d1a) | `group` | `libraries/common.xsd` |
| [`event_object_dock_too_far`](wiki:api-mdevent-event-object-dock-too-far-5a6ff60d) | `group` | `libraries/common.xsd` |
| [`event_object_docked`](wiki:api-mdevent-event-object-docked-76ee1269) | `group` | `libraries/common.xsd` |
| [`event_object_docking_aborted`](wiki:api-mdevent-event-object-docking-aborted-97c4753f) | `group` | `libraries/common.xsd` |
| [`event_object_docking_denied`](wiki:api-mdevent-event-object-docking-denied-2f977468) | `group` | `libraries/common.xsd` |
| [`event_object_docking_impossible`](wiki:api-mdevent-event-object-docking-impossible-f9c10915) | `group` | `libraries/common.xsd` |
| [`event_object_docking_queued`](wiki:api-mdevent-event-object-docking-queued-034898e8) | `group` | `libraries/common.xsd` |
| [`event_object_order_cancelled`](wiki:api-mdevent-event-object-order-cancelled-de014228) | `group` | `libraries/common.xsd` |
| [`event_object_order_finished`](wiki:api-mdevent-event-object-order-finished-6bcd7797) | `group` | `libraries/common.xsd` |
| [`event_object_order_ready`](wiki:api-mdevent-event-object-order-ready-e783d19a) | `group` | `libraries/common.xsd` |
| [`event_object_signalled`](wiki:api-mdevent-event-object-signalled-5d5b1715) | `group` | `libraries/common.xsd` |
| [`event_object_undocked_from`](wiki:api-mdevent-event-object-undocked-from-a9b8b9e5) | `group` | `libraries/common.xsd` |
| [`event_object_undocking_started`](wiki:api-mdevent-event-object-undocking-started-887ea3ea) | `group` | `libraries/common.xsd` |
| [`event_weapon_fired`](wiki:api-mdevent-event-weapon-fired-36346bd2) | `group` | `libraries/common.xsd` |
| [`signal_objects`](wiki:api-md-signal-objects-053867ba) | `group` | `libraries/common.xsd` |


[All schema types](wiki:schema-types) · [Lua / MD value types](wiki:types)