roll20 api script for having tokens be able to carry other tokens.

gistfile1.txt

/**
 * A set of chat commands used to set tokens to carry other tokens. 
 * When a token moves, the any tokens it is carrying move to its new location. 
 * 
 * The following commands are available:
 * !carry [carrierName], [carriedName']  Tells your token specified by carrierName
 *              to carry another token. The carried token will remain in place 
 *              uder the carrier token.
 * !drop [carrierName], [carriedName]   Tells your token to drop a carried token.
 * !dropAll [carrierName]       Tells your token to drop all carried tokens.
 */
 
 
/** Command one of your tokens to carry another token. */ 
var carryCmd = function(msg, myTokenName, carriedName) {
    var myToken = getToken(myTokenName);
    if(!myToken) {
        sendChat(msg.who, "/w " + msg.who + " " + myTokenName + " not found.")
        return;
    }
    var carriedToken = getToken(carriedName);
    if(!carriedToken) {
        sendChat(msg.who, "/w " + msg.who + " " + carriedName + " not found.")
        return;
    }
    
    // You must be in control of your token and the carried token.
    if(isTokenControlledBy(msg.playerid, myTokenName)) {
        if(isTokenControlledBy(msg.playerid, carriedName)) {
            _carryCmd(myToken, carriedToken);
            sendChat(msg.who, "/em : " + myTokenName + " is carrying " + carriedName);
        }
        else {
            sendChat(msg.who, "/w " + msg.who + " " + carriedName + " does not belong to you!");
        }
    }
    else {
        sendChat(msg.who, "/w " + msg.who + " " + myTokenName + " does not belong to you!");
    }
}
 
var _carryCmd = function(myToken, carriedToken) {
    // lazily make the list of carried tokens if it doesn't already exist.
    if(!myToken.carryList) {
        myToken.carryList = new Array();
    }
    
    myToken.carryList.push(carriedToken);
}
 
/** Command one of your tokens to stop carrying another token. */ 
var dropCmd = function(msg, myTokenName, carriedName) {
    var myToken = getToken(myTokenName);
    if(!myToken) {
        sendChat(msg.who, "/w " + msg.who + " " + myTokenName + " not found.")
        return;
    }
    var carriedToken = getToken(carriedName);
    if(!carriedToken) {
        sendChat(msg.who, "/w " + msg.who + " " + carriedName + " not found.")
        return;
    }
    
    // You must be in control of your token and the carried token.
    if(isTokenControlledBy(msg.playerid, myTokenName)) {
        if(isTokenControlledBy(msg.playerid, carriedName)) {
            _dropCmd(myToken, carriedToken);
            sendChat(msg.who, "/em : " + myTokenName + " dropped " + carriedName);
        }
        else {
            sendChat(msg.who, "/w " + msg.who + " " + carriedName + " does not belong to you!");
        }
    }
    else {
        sendChat(msg.who, "/w " + msg.who + " " + myTokenName + " does not belong to you!");
    }
} 
 
/** Command one of your tokens to stop carrying any tokens. */ 
var dropAllCmd = function(msg, myTokenName) {
    var myToken = getToken(myTokenName);
    if(!myToken) {
        sendChat(msg.who, "/w " + msg.who + " " + myTokenName + " not found.")
        return;
    }
    if(!myToken.carryList) {
        return;
    }
    
    // Iterate through a copy of our list instead of the actual list.
    var arrCopy = new Array();
    for(var i in myToken.carryList) {
        arrCopy.push(myToken.carryList[i]);
    }
    
    // You must be in control of your token and the carried token.
    if(isTokenControlledBy(msg.playerid, myTokenName)) {
        for(var i in arrCopy) {
            var carriedToken = arrCopy[i];
            log(carriedToken);
            _dropCmd(myToken, carriedToken);
            sendChat(msg.who, "/em : " + myTokenName + " dropped " + carriedToken.get("name"));
        }
    }
    else {
        sendChat(msg.who, "/w " + msg.who + " " + myTokenName + " does not belong to you!");
    }
}
 
var _dropCmd = function(myToken, carriedToken) {
    if(!myToken.carryList) {
        return;
    }
    var index = myToken.carryList.indexOf(carriedToken);
    if(index !== -1) {
        myToken.carryList.splice(index, 1);
    }
}
 
 
 
/** Interpret the chat commands. */
on("chat:message", function(msg) {
    var cmdName;
    var msgTxt;
    
    
    cmdName = "!carry ";
    msgTxt = msg.content;
    if(msg.type == "api" && msgTxt.indexOf(cmdName) !== -1) {
        var targetName = msgTxt.slice(cmdName.length);
        if(targetName.indexOf(",") == -1) {
            sendChat(msg.who, "/w " + msg.who + " must specify two comma-separated token names for !carry command.")
        }
        else {
            var targets = targetName.split(",");
            var me = trimString(targets[0]);
            var carried = trimString(targets[1]);
            carryCmd(msg, me, carried);
        }
    }
    
    
    cmdName = "!drop ";
    msgTxt = msg.content;
    if(msg.type == "api" && msgTxt.indexOf(cmdName) !== -1) {
        var targetName = msgTxt.slice(cmdName.length);
        if(targetName.indexOf(",") == -1) {
            sendChat(msg.who, "/w " + msg.who + " must specify two comma-separated token names for !drop command.");
        }
        else {
            var targets = targetName.split(",");
            var me = trimString(targets[0]);
            var carried = trimString(targets[1]);
            dropCmd(msg, me, carried);
        }
    }
    
    cmdName = "!dropAll ";
    msgTxt = msg.content;
    if(msg.type == "api" && msgTxt.indexOf(cmdName) !== -1) {
        var targetName = msgTxt.slice(cmdName.length);
        dropAllCmd(msg, targetName);
    }
    

});
 
 
/** Do the carrying logic when the carrier tokens move. */
on("change:graphic", function(obj, prev) {
    
    
    if(obj.carryList) {
        for(var i in obj.carryList) {
            var carried = obj.carryList[i];
            carried.set("left", obj.get("left"));
            carried.set("top", obj.get("top"));
        }
    }
    
});
 
 
////// Utility functions:
 
 
/** Returns true iff the player with the specified ID controls the token with the specified name. */
var isTokenControlledBy = function(playerID, tokenName) {
    return (getControllers(tokenName).indexOf(playerID) !== -1);
}
 
 
/** Returns the list of player IDs controlling the specified token. */
var getControllers = function(tokenName) {
    var token = getToken(tokenName);
    
    // The token doesn't exist. 
    if(token === null) {
        return [];
    }
    
    // Return a list of all player ids controlling this token, including GMs.
    else {
        var character = getCharacterOf(token);
        if(character === null) {
            return getGMs();
        }
        else {
            return character.get("controlledby").split(",");
        }
    }
    
}
 
 
/** Returns the Character that controls the specified token. */
var getCharacterOf = function(token) {
    var cID = token.get("represents");
    
    if(cID === "") {
        return null;
    }
    else {
        return getObj("character", cID);
    }
}
 
 
/**
 * Gets a token on the current map by name.
 */
var getToken = function(tokenName) {
    var curPageID = findObjs({_type: "campaign"})[0].get("playerpageid");
    return findObjs({_type: "graphic", layer: "objects", _pageid: curPageID, name: tokenName})[0];
}
 
 
/**
 * Gets the list of the player IDs for all GMs of the campaign. (Just me)
 */
var getGMs = function() {
    var result = new Array();
    
    // populate result with the player IDs of the GMs for your campaign.
    
    return result;
}
 
 
 
/** Trims a string */
var trimString = function(src) {
    return src.replace(/^\s+|\s+$/g, '');
}