Getting Trigger variables using scripts

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If you are in this tutorial, chances are, you probably want to create games using both scripts and triggers, the best of both worlds, and there are methods that allow us to do just that, it is also useful as you can use the trigger variables as cross-script variables, mini world does not allow the use of the require method²⁾ so that's a great alternative to the require as it allows us to access and use variables that can be used in all the scripts

To get global variables it's easy as we have methods to do so, they are the getGlobalVarByName that as you may have guessed from the name, lets you get the value of a global variable and setGlobalVarByName which lets you change the value of a global variable

Lets talk about this method first. This method takes two parameters:

• actionattr: number (The type of variable)
• msg: string (The name of the variable)

And returns:

• Errorcode
• Value (Depends)

We will do an use example after explaining the next method.

This method changes the value of the trigger variable that we gave. It takes three parameters

• actionattr: number (The type of variable)
• msg: string (The name of the variable)
• val (depends on actionattr)

And returns:

• Errorcode

Lets say that we want to make that when a creature is defeated a variable goes up by one, we will do that part with triggers, and when that variable is more than or equal to five, we will send a message to all players that says “You won!” and then we reset that variable back to 0, we will do that part with scripts

We start by creating a function, in this functions params are not necesary and adding the Listener with the Actor.Die (Creature dies) event and the function we created, i won't go into too much detail with this as this was explained in Event tutorial

The code should look like this:

function CreatureDefeated() 
 
end
 
ScriptSupportEvent:registerEvent([=[Actor.Die]=], CreatureDefeated)

We then add to the function the getGlobalVarByName(actionattr,msg) method, as we explained at the start of this tutorial, the actionattr method is the type of the variable that we want to get, you may be wondering, how can i know, and the answer is that this table has every type of variable possible and its value

Table

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My variable is a number, so the actionattr is 3, but after seeing the table you may start to wonder, what about the msg parameter? it's the name of the variable we want to get, the variable i created is called “MyTestVal” so the msg i must use is “MyTestVal”, but if your variable name is different then you must use your variable name as your “msg”.

function CreatureDefeated() 
    local result = VarLib2:getGlobalVarByName(3,"MyTestVal")
end
 
ScriptSupportEvent:registerEvent([=[Actor.Die]=], CreatureDefeated)

This error is common, its because getGlobalVarByName returns 2 values(errorcode and then the value) instead of just the value, if you try to use the result variable you will either get 0 (ErrorCode.OK No errors) or 1001 (ErrorCode.FAILED there was an error) the fix to this is to add another variable (local result, value = VarLib2:getGlobalVarByName(3,“MyTestVal”)

The code should look like this:

function CreatureDefeated() 
    local result, value = VarLib2:getGlobalVarByName(3,"MyTestVal")
end
 
ScriptSupportEvent:registerEvent([=[Actor.Die]=], CreatureDefeated)

or

function CreatureDefeated() 
    local _, value = VarLib2:getGlobalVarByName(3,"MyTestVal")
end
 
ScriptSupportEvent:registerEvent([=[Actor.Die]=], CreatureDefeated)

Both do the same. but the former is a better idea if you want to handle any possible errors that may occur. We then add an if statement that checks if value is greater than or equal to 5 and if its true then send a message to the player that says “You won!” and also sets our variable back to 0, the setGlobalVarByName method also has actionattr and msg, so we can copy them from our getGlobalVarByName, but the last parameter (val) is the value that we want the variable to be, in this case, 0

The code should look like this:

function CreatureDefeated() 
    local result, value = VarLib2:getGlobalVarByName(3,"MyTestVal")
    if value >= 5 then
 
        Chat:sendSystemMsg("You won!", 0)
        VarLib2:setGlobalVarByName(3,"MyTestVal",0)
 
    end
end
 
ScriptSupportEvent:registerEvent([=[Actor.Die]=], CreatureDefeated)

or

function CreatureDefeated() 
    local _, value = VarLib2:getGlobalVarByName(3,"MyTestVal")
    if value >= 5 then
 
        Chat:sendSystemMsg("You won!", 0)
        VarLib2:setGlobalVarByName(3,"MyTestVal",0)
 
    end
end
 
ScriptSupportEvent:registerEvent([=[Actor.Die]=], CreatureDefeated)

Like with global variables, with private variables we also have methods that allow us to get the values that are stored in them, the methods both follow the same structure as the global variable ones, the only change is that we first need to specify the id of the player that we want to obtain his private variale

This time we will talk about the private counterpart of the getGlobalVaByName method. This method takes three parameters:

• objid:number (The uid of the player we will get the var value)
• actionattr: number (The type of variable)
• msg: string (The name of the variable)

And returns:

• Errorcode
• Value (Depends)

We will do an use example after explaining the next method.

This method changes the value of the private variable that we gave to the player that has the uid that we gave it. It takes four parameters

• objid: number (The uid of the player we will get the var value)
• actionattr: number (The type of variable)
• msg: string (The name of the variable)
• val (depends on actionattr)

And returns:

• Errorcode

This time we will do something different, with the scripts we will do something similar, where when a player defeats a monster we will add 1 to the monsters the player has defeated, and when the player defeats a number of monsters, let's say its 5 we will display “{PlayerNickname} has leveled up” where {PlayerNickName} it's a placeholder for the player's name

Now, for this we will need a bit more experience with the basics as we are using something called a numeric for loop ((More info here Lua numeric for page and a while loop ((More info here while loop page

We start by doing the same as we did with the other example, we create a function that does not need args, we add the Listener and we add a while true loop inside the function we created, code should look something like this:

function CreatureDefeated() 
    while true do
 
    threadpool:wait(1)
 
    end
end
 
ScriptSupportEvent:registerEvent([=[Game.Start]=], CreatureDefeated)

the threadpool:wait(seconds) function is really important as if we do not add it, our game could crash, we then add inside the while loop a World:getAllPlayers(-1) -1 means all players, and we add three variables as this method returns:

• Errorcode
• The number of players
• A list of all the player's ids

But we will only need the list, after that we then add a numeric for loop with i = 1, PlayerListLength and inside that list we add the getPlayerVarByName method, we already know how to get the actionattr and the message so we will pass to the objid after showing the code

The code should look something like this:

function CreatureDefeated() 
    while true do
    local _,_,PlayerList = World:getAllPlayers(-1)
 
 
    for i=1, #PlayerList do 
        local result, value = VarLib2:setPlayerVarByName(PlayerList[i],3,"MyPrivateTestVar") 
        Chat:sendSystemMsg(value)
    end
 
    Trigger:wait(1)
 
    end
end
 
ScriptSupportEvent:registerEvent([=[Game.Start]=], CreatureDefeated)

After seeing the code, you may wonder, why are we using PlayerList[i], the answer resides on how the for loop works, the for loop works like this for initialvalue, endvalue, increment, the initial value is where we are defining the initial value of i, endvalue that is the value i will increment to and when it reaches that value, it will stop and increment which its optional and if not specified is equal to 1, the # value is equal to length of, so we are saying, the initial value of i is 1 and its the endvalue will be the PlayerList length (The current number of players) so, if there are 4 players, the playerlist length will be 4 and so, it will execute until i is equal to the end value (4 times) so what [i] does it that it calls the element in the position i of the table, let's show you with a little example

so we know that there are 4 players so the length of the playerlist will be 4, then we do the for statement

for i=1, #playerlist (we know playerlist is 4 so it will be executed and i will increment by 1 until i is equal to 4)

i -> 1 (NotSoPr17)
i -> 2 (PvpGamesAreGreat)
i -> 3 (MiniWorldPlayer)
i -> 4 (ILoveMiniWorld)

So basically PlayerList[i] is the id of the player in the position i

After this, we add an if statement that checks if the player's variable value is greater than or equal to 5, the code should look something like this

function CreatureDefeated() 
    while true do
    local _,_,PlayerList = World:getAllPlayers(-1)
 
 
    for i=1, #PlayerList do 
        local result, value = VarLib2:setPlayerVarByName(PlayerList[i],3,"MyPrivateTestVar")
 
        if value >= 5 then
 
        end
 
    end
 
    threadpool:wait(1)
 
    end
end
 
ScriptSupportEvent:registerEvent([=[Game.Start]=], CreatureDefeated)

After this, when a player defeats more than 5 monsters or players the code inside the if will execute, after this we add a local _,playerNick = Player:getNickname(PlayerList[i]) that gets the nickname of the current player and we create a function that takes a content and a playerlist and displays a message to them, the function will use the for statement for this

the function should look something like this:

function SendToAllPlayers(content,funcplayerlist) 
 
    for i=1, #funcplayerlist do
        Chat:sendSystemMsg(content, funcplayerlist[i])
    end
 
end

After this, we add to our if statement that checks if the value is greater than or equal to 5 and we use the setPlayerVarByName method with the objid as playerlist[i]

If you are confused, which is natural when learning something new, here is the code

function SendToAllPlayers(content,funcplayerlist) 
 
    for i=1, #funcplayerlist do
        Chat:sendSystemMsg(content, funcplayerlist[i])
    end
 
end
 
function CreatureDefeated() 
    while true do
    local _,_,PlayerList = World:getAllPlayers(-1)
 
 
    for i=1, #PlayerList do 
        local result, value = VarLib2:getPlayerVarByName(PlayerList[i],3,"MyPrivateTestVar")
 
        if value >= 5 then
 
            local _,playerNick = Player:getNickname(PlayerList[i]) 
            SendToAllPlayers(playerNick .. " has leveled up!", PlayerList)
            VarLib2:setPlayerVarByName(PlayerList[i],3,"MyPrivateTestVar",0)
        end
 
    end
 
    threadpool:wait(1)
 
    end
end
 
ScriptSupportEvent:registerEvent([=[Game.Start]=], CreatureDefeated)