Extended Event Handlers (XEH) by Solus and Killswitch

This addon allows a virtually infinite amount of event handlers to be used together from different addons. The event handlers are executed for the matching class and all inheriting classes. The event handler init line also contains the extended event handler class to look for, so you can have a custom inheritance for custom units.

Normally event handlers can only be added in configs, and trying to add a new event handler caused all previous event handlers to be overwritten. This addon allows that limitation to be overcome. This is mostly useful for having addons that can add different functionality, for example in OFP addons that had their own event handlers wouldn't inherit default event handlers, such as a custom unit with EHs being used with ECP or FFUR wouldn't have the ECP or FFUR effects.

This adds support for using extended event handlers for all Arma event types

This allows a virtually infinite amount of fired event handlers to be used together from different addons.

The extended fired event handler has several different parts:

• First the extended init EH is run for all units to add together and compile all of the inherited fired event handlers and use setVariable to attach those to the unit.
• The extended fired event handler is added to the base class called Extended_EventHandlers so that all the CfgVehicles' class EventHandlers inherit it. When a unit fires and sets off the event handler the shot is immediately captured in the same game state cycle. Then the compiled extended fired events are called by using getVariable to retrieve them from the unit.

The fired event handler init line contains the extended event handler class to look for, so you can have a custom inheritance for custom units. The event handlers are executed for the matching class and all inheriting classes.

It allows more fired events to be used together, for example a script that makes shots affected by wind and a tracer script could be used together.

There are two example Extended Init addons included to demonstrate how to assign new event handlers and the event handler inheritance. The example pbos should not be installed except for testing.

There is an example addon included to demonstrate how to assign new fired event handlers and the event handler inheritance. The example also has a quickly called function that is able to capture information on the shot in the same game state cycle before the shot is updated and moves away from it's starting position and changes it's status. The example pbo should not be installed except for testing.

The addon “SightAdjustment_AutoInit.pbo” is an addon that makes gmJamez' “GMJ_SightAdjustment” addon compatible with XEH.

Note to addon makers: Before XEH 1.1, you had to make sure to add a “;” at the end of your extended init line to separate it from other extended inits. This is no longer necessary - the Extended Init EH will separate them automatically, so ending without one won't cause a problem

1.3: Limiting certain event handler to a specific vehicle class

The example addon “SLX_Advanced_Init_Example” shows how to create an XEH init EH that will only be used on units that are of the class SoldierWB, ie the West “Rifleman”. Units that inherit from “SoldierWB”, eg the Grenadier, won't run the init EH.

One can do the same thing for the other XEH event types. For example, to add a “GetIn” event handler that works only on the the vehicle XYZ_BRDM2, but not on the XYZ_BRDM2_ATGM variant you would do something like this:

...
class Extended_GetIn_Eventhandlers
{
    class XYZ_BRDM2
    {
        class XYZ_BRDM2_GetIn
        {
            scope = 0;
            getin = "[] exec '\xyz_brdm2\getin.sqf'";
        };
    };
};
 
class Vehicles
{
    ...
    class XYZ_BRDM2: BRDM2
    {
        ...
    };
    class XYZ_BRDM2_ATGM: XYZ_BRDM2
    {
        ...
    };
 
};

Note that within that innermost XEH class, you have to put a string value with the same name as the desired event handler. In the above example it was “getin”. For the “fired” event handler, you would use

...
class Extended_Fired_Eventhandlers
{
    class SoldierEB
    {
        class XYZ_SoldierEB_fired
        {
            scope=0;
            // We wish to make a SoldierEB-specific *Fired* EH, so the
            // property name should be "fired" 
            //
            fired = "_this call XYZ_SoldierEB_fired";
        };
    };
};
...

With XEH 1.5, you can exclude one or more subtypes of a vehicle from getting a certain XEH event handler. To do this, you add a directive, exclude, in an inner, “composite” XEH class (introduced in 1.3)

Here's an example of how to exclude the west pilot class from running the basic Man class XEH init event handler. Instead, there's a special init for the pilot (“SoldierWPilot”). Note that all subclasses of “SoldierWPilot” will be excluded from using the basic class Man XEH init too.

/*
 *   Init XEH exclusion example 1
 */
class CfgPatches
{
   class xeh_exclusion_example1
   {
       units[]={};
       weapons[]={};
       requiredVersion=0.1;
       requiredAddons[]={"Extended_Eventhandlers"};
   };
};
 
class Extended_Init_Eventhandlers
{
    class Man
    {
        // To use the exclude directive, we'll have to make this an
        // "inner" (composite) XEH init EH class
        class XEH_Exclusion1_Man
        {
            exclude="SoldierWPilot";
            init = "[] execVM '\xeh_exclusion_example1\init_man.sqf'";
        };
    };
 
    class SoldierWPilot
    {
        xeh_init = "[] execVM '\xeh_exclusion_example1\init_west_pilot.sqf'";
    };
};

In the second example, we'll exclude both the standard west and east pilots and add unique init EH:S to them and the BIS Camel pilot. To do so, use the exclude[] directive in array form:

/*
 *   Init XEH exclusion example 2
 */
class CfgPatches
{
   class xeh_exclusion_example2
   {
       units[]={};
       weapons[]={};
       requiredVersion=0.1;
       requiredAddons[]={"Extended_Eventhandlers"};
   };
};
 
class Extended_Init_Eventhandlers
{
    class Man
    {
        // To use the exclude directive, we'll have to make this an
        // "inner" (composite) XEH init EH class
        class XEH_Exclusion2_Man
        {
            exclude[] = {"SoldierWPilot", "SoldierEPilot"};
            init = "[] execVM '\xeh_exclusion_example2\init_man.sqf'";
        };
    };
 
    // All descendants of SoldierEPilot will use this XEH init EH
    class SoldierEPilot
    {
        xeh_init = "[] execVM '\xeh_exclusion_example2\init_east_pilot.sqf'";
    };
 
    // Using scope=0, only SoldierWPilot will get this particular XEH init
    class SoldierWPilot
    {
        scope=0;
        xeh_init = "[] execVM '\xeh_exclusion_example2\init_west_pilot.sqf'";
    };
 
    // Here, we add an event handler for the BIS Camel Pilot (which is a
    // descendant of "SoldierWPilot". It won't run "init_west_pilot.sqf" though
    // since we used "scope=0" above.
    class BISCamelPilot
    {
        xeh_init="[] execVM'\xeh_exclusion_example2\init_west_camel_pilot.sqf'";
    };
};

You can do the same thing with the other XEH event types (fired, hit and so on).

Normally, when a player respawns into a new unit (object), the init event handler is not executed again. However, with XEH 1.8, you can make an XEH init event handler be rerun when the new unit spawns. To do so, declare your init EH as a “composite EH class” (described above). Then, add a property to it called “onRespawn” and set it to true (the number 1).

Here's an example that shows how to do it:

#define false 0
#define true  1
 
class Extended_Init_Eventhandlers
{
    class Man
    {
        class SLX_XEH_RespawnInitMan
        {
            onRespawn = true;                    // Run this even after respawn
            init      = "_this call My_Respawn_InitEH";
        };
    };
};

The example above will cause all classes that are descendants of class “Man” to have the function “My_Respawn_InitEH” called both when the unit is created and after a player has respawned into a new unit.

Note that unless you have “onRespawn=true” like above, XEH will use the default ArmA behavior which is to NOT run the init EH when a unit respawns.

IMPORTANT: This feature will only work on the player's unit - AI units that respawn won't have their XEH init EH:s re-executed. (If someone can figure out a trick to identify playable units in a MP mission, this limitation could be removed)

You can get a string with the version of Extended_Eventhandlers using the “localize” command. Here's an example function which will return the version as a decimal number or “0” if XEH isn't installed;

/*
    Return the version of Extended_Eventhandlers, or 0 if the addon
    isn't installed.
*/
_fXEHversion = {
    private ["_str", "_cfg", "_ver"];
    _cfg=(configFile/"CfgPatches"/"Extended_Eventhandlers"/"SLX_XEH2_Version");
    _ver=0;
 
    _str=localize "STR_SLX_XEH_VERSION";
    if !(_str == "") then {
        _ver=call compile _str;
    } else {
        // XEH version 1.8 and earlier lacks the stringtable version
        if (isNumber _cfg) then {
            _ver=getNumber _cfg;
        };
    };
    _ver
};

Another addition is a way to put code that you want to run only once in a new class, Extended_PreInit_EventHandlers. Anything in that class will be called early and before any of the normal extended init event handlers have run.

Here's an example: let's say there's an addon with the following XEH init:

// Addon: SLX_MyAddon (old)
class Extended_Init_EventHandlers
{
    class Man
    {
        SLX_Man_init="_this call compile preprocessFile'\SLX_MyAddon\init.sqf'";
    };
};

Using the “pre-init” system, that can be rewritten as:

// Addon: SLX_MyAddon (new)
class Extended_PreInit_EventHandlers
{
    // The name "SLX_MyAddon_init" needs to be unique
    SLX_MyAddon_init="SLX_fInit=compile preprocessFile'\SLX_MyAddon\init.sqf'";
};
class Extended_Init_EventHandlers
{
    class Man
    {
        // Call the function we loaded in the PreInit class
        SLX_Man_init="_this call SLX_fInit";
    };
};

Warning: if you write your addon using this new “pre-init” system, keep in mind that it won't work with XEH versions older than 1.9.

Two new event handler types can be used to execute things at a later stage, when all XEH init EH:s have run and all mission.sqm init lines have been processed by ArmA. It happens just before the mission's “init.sqf” is executed.

The PostInit handler mirrors the pre-init event handler introduced in 1.9 and will make a code snippet run once per mission. Example:

class Extended_PostInit_EventHandlers
{
    // Run "late_init.sqf" just before the mission's init.sqf and after
    // all other init EH:s and mission editor init lines have been processed
    SLX_MyAddon_postinit="[] execVM 'SLX_MyAddon\late_init.sqf";
};

The other event handler, InitPost type mimics the mission editor init lines in that it will be run once on every unit and vehicle in the mission. You write the InitPost EH just like you would the normal XEH init, fired etc handlers. That means you have to wrap the handler in the desired vehicle/unit class for which you want the InitPost EH applied. As an example, you could use this to set a per-unit variable that's needed for your addon. It needs to be done for all units that are derived from the CAManBase class. Here's how it would look:

class Extended_InitPost_EventHandlers
{
    class CAManBase
    {
        // Make sure everyone is happy when the mission starts
        SLX_MyAddon_init="_this setVariable ['slx_myaddon_ishappy', true]";
    };
};

1.93 (Feb 16, 2009)
Fixed: empty vehicles created after the mission started did not get their InitPost handlers called.

1.92 (Feb 09, 2009)
Changed: Some optimizations made (eg use pre-compiled XEH init functions).

1.91 (Dec 20, 2008) (Unofficial, for use with the ACE mod) Added: New “post-init” feature that can be used to have a script run once at the end of mission initialisation, after all init EH:s and mission init lines have executed, but before the mission's init.{sqs,sqf} is processed.

Added: There's also a per-unit, “InitPost” XEH framework which lets you run scripts at the end of mission init. Unlike the PostInit event handlers described above, these snippets run once for every unit in the mission. (The name of this framework may change in the future to avoid confusion with “PostInit”)

1.9 (Sep 21, 2008)
Fixed: before, vehicle crews would not have their XEH init EH:s run until just after the mission started. Now they are run before mission start. Added: A stringtable with the version of XEH in STR_SLX_XEH_VERSION and STR_SLX_XEH2_VERSION for use with the “localize” command. Added: a way to have run-once, “pre-init” code run using the new Extended_PreInit_EventHandlers class.

1.8 (Sep 7, 2008)
Fixed: game logics inside vehicles would cause a performance drop due to a infinite recursion in the code that handles initialisation of vehicle crews. Thanks to UNN for the bug report! Added: you can make XEH init event handlers execute when players respawn by using an inner XEH class and the “onRespawn” boolean property.

1.7 (Mar 16, 2008)
Fixed: Removed XEH from class Static, which stops ArmA from crashing to desktop when resuming saved games.

1.6 (Mar 15, 2008)
Fixed: The “exclude” property will apply to the specified class(es) and all subclasses thereof.

1.5 (Mar 15, 2008)
Added: Composite (“inner”) XEH classes can have an extra property, “exclude” which is either a string or an array of strings with the class name(s) of vehicles that should not get a particular XEH event handler.

1.4 (Mar 15, 2008)
Added: “Static” class vehicles can now have XEH event handlers. Added: A respawn monitor that restores non-init XEH event handlers after the player respawns. Many thanks to Sickboy, LoyalGuard, ViperMaul for the initial research and suggestions!

1.3 (Feb 9, 2008)
Added: The ability to use “nested” XEH classes with a “scope” feature to limit certain event handlers to objects of specific classes.

1.2 (Jan 29, 2008)
Fixed: SightAdjustment_AutoInit. Fixed: Extended Dammaged EventHandler.

1.1 (Jan 26, 2008)
Fixed: XEH can now handle extended event handlers that are missing a trailing semicolon. Fixed: the example addons now require the Extended_Eventhandlers addon instead of the two older ones. Also, the debug sideChats are now guaranteed to be seen when previewing a mission with the example addons loaded. Fixed: XEH init EH:s are now actually being called on units inside vehicles.

1.0 Initial Release (Dec 31, 2007)
Combined Extended Init, Fired, and Other event handlers. Thanks to Killswitch for combining them and adding the other extended event handlers! Added signature and bikey.

1.26
Fixed signature files, bikey, and .pbos.

1.25
Fixed signature files and added bikey.

1.2
Added signature file. Fixed a bug that caused crashes on some missions. Thanks to LCD344! Changed ExecVM to Call Compile. Thanks to UNN!

1.1
Fixed people in vehicles having no inits. Included SightAdjustment example “bridge” addon that allows the GMJ_SightAdjustment addon to be used with other extended init event handler addons.

1.0 Initial Release

1.0 @ 12-09-07 Initial release

PMC Tactical forum topic.