Keeping the scoreboard up-to-date

In order to update scoreboard we need to do two things:

1. Write the logic for updating the UI

2. Adding hooks to trigger this logic where necessary

Writing the client-side logic

We want to be able to add/update a player in the scoreboard when they join and remove a player when they leave.

In data/CoinCollection/client/gui/scoreBoard.tscript add the following section to the bottom:

//-----------------------------------------------------------------------------
// ScoreBoardGUI data handler methods
//-----------------------------------------------------------------------------

function ScoreBoardGUI::upsertPlayer(%this, %clientID, %name, %score, %kills, %deaths) {
    %text = StripMLControlChars(%name);
    if (%score !$= "null")
        %text = setField(%text, 1, %score);
    %text = setField(%text, 2, %kills);
    %text = setField(%text, 3, %deaths);

    // Update or add the player to the control
    if (ScoreBoardGUIList.getRowNumById(%clientId) == -1)
        ScoreBoardGUIList.addRow(%clientId, %text);
    else ScoreBoardGUIList.setRowById(%clientId, %text);

    // Sorts by score
    ScoreBoardGUIList.sortNumerical(1, false);
    ScoreBoardGUIList.clearSelection();
}

function ScoreBoardGUI::removePlayer(%this, %clientId) {
    PlayerListGuiList.removeRowById(%clientId);
}

So lets see what this does. The upsertPlayer function first creates a new variable %text which stores name, score, kills and deaths with columns seperated by tabs. Then we check if there is already stored a row with that id. If not, then we add a new row else we update the row with that id. Finally we sort the list by column 1 (the second column because it starts at 0).

The removePlayer function simply removes the row with the player's ID.

In order to trigger these two functions we will use the network message system. Let's add the client-side listeners right away in the top of the scoreBoard.tscript file:

//-----------------------------------------------------------------------------
// Callbacks
//-----------------------------------------------------------------------------
addMessageCallback('MsgClientWelcome', SBGUIWelcome);
addMessageCallback('MsgClientJoin', SBGUIPlayerJoined);
addMessageCallback('MsgClientDrop', SBGUIPlayerLeft);
addMessageCallback('MsgClientScoreChanged', SBGUIScoreChanged);

function SBGUIWelcome(%msgType, %msgString, %clientName, %clientId,
        %isAI, %isAdmin, %isSuperAdmin) {
    ScoreBoardGUI.clear();
    ScoreBoardGUI.upsertPlayer(%clientId, detag(%clientName), 0, 0, 0);
}

function SBGUIPlayerJoined(%msgType, %msgString, %clientName,
        %clientId, %score, %kills,
        %deaths, %isAI, %isAdmin, %isSuperAdmin) {
    ScoreBoardGUI.upsertPlayer(%clientId, detag(%clientName), %score, %kills, %deaths);
}

function SBGUIPlayerLeft(%msgType, %msgString, %clientName, %clientId) {
    ScoreBoardGUI.removePlayer(%clientId);
}

function SBGUIScoreChanged(%msgType, %msgString, %clientName,
        %clientId, %score, %kills, %deaths) {
    ScoreBoardGUI.upsertPlayer(%clientId, detag(%clientName), %score, %kills, %deaths);
}

Here we use detag on the clientName, that is because the clientName is a tagged string, so we need to look up the clientName ID to get the string.

Adding the hooks on the server

We have four different callbacks we need to implement. Let's start with the callback MsgClientScoreChanged, we will trigger that one whenever we pick up a coin. In data/CoinCollection/server/coin.tscript add:

messageAll('MsgClientScoreChanged', -1, %col.client.playername,
    %col.client, %col.client.coinsFound,
    %col.client.kills, %col.client.deaths);

Right after:

%col.client.coinsFound++; // Automatically starts at 0

The three other hooks should happen whenever a client enters or leaves the game. So let's open up data/CoinCollection/gamemode.tscript and change onClientEnterGame and add onClientLeaveGame :

function CoinCollectionGameMode::onClientEnterGame(%this, %client) {
    //Set the player name based on the client's connection data
    %client.setPlayerName(%client.connectData);

    %this.spawnControlObject(%client);

    // Welcome the client
    messageClient(
            %client, 'MsgClientWelcome',
                    "\c2Welcome to the Torque demo app %1.",
                    %client.playername,
                    %client,
                    %client.isAiControlled()
            );

    // Inform the client about everyone else
    foreach(%other in ClientGroup) {
        if (%other == %client) {
            continue;
        }

        messageClient(%client, 'MsgClientJoin', -1,
                    %other.playername,
                    %other, %other.coinsFound,
                    %other.kills, %other.deaths);
    }

    // Inform everyone else about the client
    messageAllExcept(
            %client,
                    "-1",
                    'MsgClientJoin',
                    "\c1 % 1 joined the game.",
                    %client.playername,
                    %client,
                    %client.coinsFound,
                    %client.kills, %client.deaths,
                    %client.isAiControlled()
            );
}

function CoinCollectionGameMode::onClientLeaveGame(%this, %client) {
    // Inform everyone that the client left
    messageAllExcept(
            %client,
                    "-1",
                    'MsgClientDrop',
                    "\c1 % 1 left the game.",
                    %client.playername,
                    %client,
                    %client.isAiControlled()
            );
}