[LE] Event Headers called as Functions?

[qwertypol012]

First of all, i'm an ultra newbie in Papyrus Scripting, hence i'm asking. I recently found some mods which utilize some event headers as functions (or how should i put it correctly? I don't actually know what's the correct terms anyway). For example:

Function OnInit()
 ;function's stuff
EndFunction

Function OnUpdate()
 ;function's stuff
EndFunction

Function OnAnimationEvent(objectreference akSource, String asEventName)
 ;function's stuff
EndFunction

So, this works? and what are the uses of this form of coding?

[ReDragon2013]

Afaik there is no different between both variants

Function OnInit()
 ;function's stuff
EndFunction

Function OnUpdate()
 ;function's stuff
EndFunction

Function OnAnimationEvent(Objectreference akSource, String asEventName)
 ;function's stuff
EndFunction

EVENT OnInit()
ENDEVENT

EVENT OnUpdate()
ENDEVENT

EVENT OnAnimationEvent(Objectreference akSource, String asEventName)
ENDEVENT

because all of these are native methods, hardcoded to papyrus engine. The different comes true if you want to use your own function as event.

 

For example: I made a new function to "critter.psc" and called this by event syntax.

EVENT OnCritterStop(Int i)
    ; stuff here
ENDEVENT

After some time of reasearching I found out it would be better to use the normal way as function syntax.

FUNCTION OnCritterStop(Int i)
    ; stuff here
ENDFUNCTION

Why? Function do not clash each other, but events are able to run at the same time. This could lead to mistakes.

[npdogg]

The use of this form of coding is to make it harder to understand and more prone to programming mistakes.

 

Even if the compiler will recognize either keyword, you should use "Event" for events and "Function" for user-defined functions. It makes it easier to understand what your script is supposed to do.

[qwertypol012]

 

 

Afaik there is no different between both variants

Function OnInit()
 ;function's stuff
EndFunction

Function OnUpdate()
 ;function's stuff
EndFunction

Function OnAnimationEvent(Objectreference akSource, String asEventName)
 ;function's stuff
EndFunction

EVENT OnInit()
ENDEVENT

EVENT OnUpdate()
ENDEVENT

EVENT OnAnimationEvent(Objectreference akSource, String asEventName)
ENDEVENT

because all of these are native methods, hardcoded to papyrus engine. The different comes true if you want to use your own function as event.

 

For example: I made a new function to "critter.psc" and called this by event syntax.

EVENT OnCritterStop(Int i)
    ; stuff here
ENDEVENT

After some time of reasearching I found out it would be better to use the normal way as function syntax.

FUNCTION OnCritterStop(Int i)
    ; stuff here
ENDFUNCTION

Why? Function do not clash each other, but events are able to run at the same time. This could lead to mistakes.

 

 

This actually makes sense. Though i'm interested if anyone has more informations about it.

 

@ npdogg

The fact is that (some also based on my strong assumption), such method is used by many mods (some are quite popular), such as Enhanced Blood Textures, Engarde (recently new combat mod), and probably chesko's mods (because the author of a mod i found using this method said that he used a method from chesko's Frostfall in his script).

Edited June 22, 2019 by qwertypol012

[npdogg]

The fact is that (some also based on my strong assumption), such method is used by many mods (some are quite popular), such as Enhanced Blood Textures, Engarde (recently new combat mod), and probably chesko's mods (because the author of a mod i found using this method said that he used a method from chesko's Frostfall in his script).

 

Well there's a difference between Chesko doing it and someone else who looked at Chesko's scripts doing it. I can't think of any useful reason to use the Event keyword for a function. Only one thread of execution can be in a script at a time, I don't see how changing the keyword from Function to Event would change that.

[cdcooley]

There is absolutely no difference between Function and Event once the script is compiled so technically you can use Function everywhere without any problems. The use of Event is purely a cosmetic feature to make the bits of code called by the game engine itself stand out.

 

The Champollion script decompiler is used by many people to get source code for mods that only included the compiled scripts. That program generates scripts that use Function everywhere instead of Event. My guess is that this trend started when people used that tool and copied its results into their own mods.

[Rizalgar]

TL;DR comments. The differences between using Events and Functions of the same nature is that you can choose when to call said functions. AFAIK, an Event OnItemAdded will fire every time an item is added, however the Function OnItemAdded would be fired when the script calls it to fire. In example:

Function InitiateAdd(references here) ;A player created function to determine when OnItemAdded is fired.

    OnItemAdded() ;Calls the function, starting it

EndFunction

Function OnItemAdded() ;The function is now initiated

EndFunction

I may be incorrect, as a matter of fact I'm certain I am, but that is the way it seems to me. I've done enough coding to know the different between an event and function, but I'm still a derp.

 

Edit - I mostly work with my own functions that call to other functions, I've never actually tried calling an OnItemAdded function on itself alone, does it fire every time an item is added? Feel free to chime in and correct me on my comment.

Edited June 23, 2019 by Rizalgar

[RichWebster]

I use the Event header for things that I use as events. For example when a quest starts and I want it to run some logic I'll created a custom Event like Startup() in my quest script, and just call it like a function from my stage fragment. Like so:

 

;Fragment
kmyQuest.Startup()

;Quest script
Event Startup()
  ;Do some cool stuff
EndEvent

 

Just remember not to use event names that already exist in the script you're extending, for example don't make your own OnActivate() event in a script that extends ObjectReference.

[npdogg]

I use the Event header for things that I use as events. For example when a quest starts and I want it to run some logic I'll created a custom Event like Startup() in my quest script, and just call it like a function from my stage fragment. Like so:

 

;Fragment
kmyQuest.Startup()

;Quest script
Event Startup()
  ;Do some cool stuff
EndEvent

Just remember not to use event names that already exist in the script you're extending, for example don't make your own OnActivate() event in a script that extends ObjectReference.

 

 

Yeah, this is the kind of thing that is not great to see. At first glance it makes it look like your script is listening for the "Startup" event, when in fact there is no such thing. More confusion, less readability.

 

Ultimately the fault lies with the language design in being too permissive of bad syntax.

[RichWebster]

 

I use the Event header for things that I use as events. For example when a quest starts and I want it to run some logic I'll created a custom Event like Startup() in my quest script, and just call it like a function from my stage fragment. Like so:

Â

;Fragment
kmyQuest.Startup()

;Quest script
Event Startup()
  ;Do some cool stuff
EndEvent

Just remember not to use event names that already exist in the script you're extending, for example don't make your own OnActivate() event in a script that extends ObjectReference.

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Yeah, this is the kind of thing that is not great to see. At first glance it makes it look like your script is listening for the "Startup" event, when in fact there is no such thing. More confusion, less readability.

Â

Ultimately the fault lies with the language design in being too permissive of bad syntax.

It is listening for a startup event, and it's called from the fragment. It's probably personal preference, but I like to organise my code in how it behaves and is used.