Get Programming with JavaScript

Get Programming with JavaScript - Listing 9.12

Listing 9.12 - A Player constructor function

// The spacer namespace

var spacer = {
    blank: function () {
        return "";
    },

    newLine: function () {
      return "\n";
    },

    line: function (length, character) {
        var longString = "****************************************";
        longString += "----------------------------------------";
        longString += "========================================";
        longString += "++++++++++++++++++++++++++++++++++++++++";
        longString += "                                        ";

        length = Math.max(0, length);
        length = Math.min(40, length);
        return longString.substr(longString.indexOf(character), length);
    },

    wrap : function (text, length, character) {
        var padLength = length - text.length - 3;
        var wrapText = character + " " + text;
        wrapText += spacer.line(padLength, " ");
        wrapText += character;
        return wrapText;
    },

    box: function (text, length, character) {
        var boxText = spacer.newLine();
        boxText += spacer.line(length, character) + spacer.newLine();
        boxText += spacer.wrap(text, length, character) + spacer.newLine();
        boxText += spacer.line(length, character) + spacer.newLine();
        return boxText;
    }
};


// The Place constructor

var Place = function (title, description) {
    var newLine = spacer.newLine();

    this.title = title;
    this.description = description;
    this.items = [];
    this.exits = [];

    this.getItemsInfo = function () {
        var itemsString = "Items: " + newLine;
        this.items.forEach(function (item) {
            itemsString += "   - " + item;
            itemsString += newLine;
        });
        return itemsString;
    };

    this.getExitsInfo = function () {
        var exitsString = "Exits from " + this.title;
        exitsString += ":" + newLine;

        this.exits.forEach(function (exit) {
            exitsString += "   - " + exit.title;
            exitsString += newLine;
        });

        return exitsString;
    };

    this.getTitleInfo = function () {
        return spacer.box(
            this.title,
            this.title.length + 4,
            "="
        );
    };

    this.getInfo = function () {
        var infoString = this.getTitleInfo();
        infoString += this.description;
        infoString += newLine + newLine;
        infoString += this.getItemsInfo() + newLine;
        infoString += this.getExitsInfo();
        infoString += spacer.line(40, "=") + newLine;
        return infoString;
    };


    this.showInfo = function () {
        console.log(this.getInfo());
    };

    this.addItem = function (item) {
        this.items.push(item);
    };

    this.addExit = function (exit) {
        this.exits.push(exit);
    };
};


// The Player constructor

var Player = function (name, health) {
    var newLine = spacer.newLine();

    this.name = name;
    this.health = health;
    this.items = [];
    this.place = null;

    this.addItem = function (item) {
        this.items.push(item);
    };

    this.getNameInfo = function () {
        return this.name;
    };

    this.getHealthInfo = function () {
        return this.name + " has health " + this.health;
    };

    this.getPlaceInfo = function () {
        return this.name + " is in " + this.place.title;
    };

    this.getItemsInfo = function () {
        var itemsString = "Items:" + newLine;

        this.items.forEach(function (item, i) {
            itemsString += "   - " + item + newLine;
        });

        return itemsString;
    };

    this.getInfo = function (character) {
        var place = this.getPlaceInfo();
        var health = this.getHealthInfo();
        var longest = Math.max(place.length, health.length) + 4;

        var info = spacer.box(this.getNameInfo(), longest, character);
        info += spacer.wrap(place, longest, character);
        info += spacer.newLine() + spacer.wrap(health, longest, character);
        info += newLine + spacer.line(longest, character);

        info += newLine;
        info += "  " + this.getItemsInfo();
        info += newLine;
        info += spacer.line(longest, character);
        info += newLine;

        return info;
    };

    this.showInfo = function (character) {
        console.log(this.getInfo(character));
    };
};


// Testing Player

var library = new Place(
    "The Old Library",
    "You are in a library. Dusty books line the walls."
);

var player1 = new Player("Kandra", 50);
player1.place = library;
player1.addItem("a rusty key");
player1.addItem("The Sword of Doom");

player1.showInfo("=");

Further Adventures

Listing 9.12 - A Player constructor function - Tasks 1 to 3

Test out the constructor by creating a couple of Player objects.
Add items for each player.
Display each player's info.

// Create some places for the players
var kitchen = new Place(
    "The Kitchen",
    "You are in the kitchen. There is a disturbing smell."
);

var hall = new Place(
    "The Main Hall",
    "You are in a large hall. It is strangely empty."
);


// create some players
var player2 = new Player("Dax", 100);
var player3 = new Player("Jahver", 200);


// where are they?
player2.place = kitchen;
player3.place = hall;


// give them some items
player2.addItem("a piece of cheese");
player2.addItem("a lucky rope");

player3.addItem("a whirlpool of infinity");


// display their info
player2.showInfo();
player3.showInfo();

Listing 9.12 - A Player constructor function - Task 4

Write a method to drop the last item in a player's items array.

this.dropLastItem = function () {
    this.items.pop();
};