set bj_wantDestroyGroup = true ?

08-17-2009, 02:21 AM

I don't understand this line of code exactly:

JASS:

set bj_wantDestroyGroup = true

Can someone explain what it does and when to use it and when not to use it?

I added it in front of some of my GUI triggers because I understood (perhaps incorrectly) that it is supposed to clean up leaks in a trigger like this:

Trigger:

Farm Income

Events

Time - IncomeTimer expires

Conditions

Actions

Custom script: set bj_wantDestroyGroup = true

Unit Group - Pick every unit in (Units of type Farm) and do (Actions)

Loop - Actions

Player - Add 40 to (Owner of (Picked unit)) Current gold

Player - Add 20 to (Owner of (Picked unit)) Current lumber

08-17-2009, 02:32 AM	#2
TotallyAwesome	It sets a global variable to "true". The function below, that picks units, uses this variable to identify if it should destroy the group after the actions are done, or not. Just put it JASS: set bj_wantDestroyGroup = true always there, and you won't leak groups.

08-17-2009, 02:59 AM	#3
Fluff	Ok, that's what I thought, I guess. Is it okay to use it in a GUI trigger like I posted? I ask because as far as I can tell, that trigger only works for the first Farm unit and then stops.

08-17-2009, 03:54 AM	#4
Pyrogasm	It should work fine in a situation like that; that's what it's designed to be used for.

08-17-2009, 05:21 AM	#5
Fluff	That trigger seems to only work for units owned by Player 1, which is weird. I don't know why that is.

08-17-2009, 09:17 AM	#6
0zyx0	That's because Trigger: Unit Group - Pick every unit in (Units of type Farm) and do (Actions) First creates a group called g and puts every Farm owned by player 1 in it, and then adds all units in that group to another group. If bj_wantDestroyGroup is true, it destroys the group g the first time the content of one group is added to another group.

08-17-2009, 09:48 AM

Maxus

Here's what it does if you look inside:

JASS:

function ForGroupBJ takes group whichGroup, code callback returns nothing
    // If the user wants the group destroyed, remember that fact and clear
    // the flag, in case it is used again in the callback.
    local boolean wantDestroy = bj_wantDestroyGroup
    set bj_wantDestroyGroup = false

    call ForGroup(whichGroup, callback)

    // If the user wants the group destroyed, do so now.
    if (wantDestroy) then
        call DestroyGroup(whichGroup)
    endif
endfunction

So if you set bj_wantDestroyGroups = true, unit group which units are picked from is destroyed at the end of this script, which prevents from leaking and this global variable is set to false again.

But the same problem you have happened to me when I was picking unit of type. I think maybe it destroys the group before using more than one players. I used this while having only Player 7 units of this type and nothing happened (he may have started with Player 1).

I suggest that using classical way for destroying groups is better, this helped me solve the problem:
You must have a Unit Group variable type like "TempGroup" declared in globals:

Trigger:

Farm Income

Events

Time - IncomeTimer expires

Conditions

Actions

Set TempGroup = (Units of type Farm)

Unit Group - Pick every unit in TempGroup and do (Actions)

Loop - Actions

Player - Add 40 to (Owner of (Picked unit)) Current gold

Player - Add 20 to (Owner of (Picked unit)) Current lumber

Custom script: call DestroyGroup(udg_TempGroup)

08-17-2009, 11:37 AM

Anitarf

The problem isn't in ForGroupBJ, it's in GetUnitsOfTypeIdAll:

function GetUnitsOfTypeIdAll takes integer unitid returns group
    local group   result = CreateGroup()
    local group   g      = CreateGroup()
    local integer index

    set index = 0
    loop
        set bj_groupEnumTypeId = unitid
        call GroupClear(g)
        call GroupEnumUnitsOfPlayer(g, Player(index), filterGetUnitsOfTypeIdAll)
        call GroupAddGroup(g, result)

        set index = index + 1
        exitwhen index == bj_MAX_PLAYER_SLOTS
    endloop
    call DestroyGroup(g)

    return result
endfunction

Or, more precisely, another function it calls:

function GroupAddGroup takes group sourceGroup, group destGroup returns nothing
    // If the user wants the group destroyed, remember that fact and clear
    // the flag, in case it is used again in the callback.
    local boolean wantDestroy = bj_wantDestroyGroup
    set bj_wantDestroyGroup = false

    set bj_groupAddGroupDest = destGroup
    call ForGroup(sourceGroup, function GroupAddGroupEnum)

    // If the user wants the group destroyed, do so now.
    if (wantDestroy) then
        call DestroyGroup(sourceGroup)
    endif
endfunction

And this is why GUI sucks.