Tutorial: Flexbox dividers with positioned labels over top

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It’s so frustrating to make a horizontal ruler with label text positioned on top of it. There are many different ways to do it but they require a lot of custom CSS that makes it hard for you to easily move the label around to a new position if you need to. I’ve come up with a way to fix that problem using FlexBox and I wanted to share. This JsFiddle will let you select from a few different styles of horizontal rulers, whether it is a full span of fixed width and where the label should be positioned in just a few lines of code. Enjoy!

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Highcharts Tutorial: Set Custom Tooltip Date Format

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high charts custom date format in tooltip

I spent a good 4 hours trying to figure out how to get HighCharts to use a custom date in the tooltip without using the custom tooltip formatter. Geesh! Why is it so painful?? Anyways, here is a JSFiddle showing how you can add your own custom formats to HighCharts and then use them in the date formats on the tooltip. In this example I’ve added a %c and then I can use that anywhere in HighCharts that I want to use my custom date formatting.

http://jsfiddle.net/c9mm9505/4/

The Game Plan: Getting Started

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Your game design can run fairly smoothly or it can be a continuous cesspool of hardships and setbacks and pain points. In the next few series of posts I’m going to try and help walk you through the process of getting your game up and off the ground, from what you’re envisioning in your head to an actual working version. So, let’s get started.

1. Get It Out Of Your Head

It’s time you pull out a pencil, pen, or open your laptop to a writing program. First thing’s first, you have to get your game out of your head. Write it down and put it somewhere you can reference it later.

2. Writer’s Block

So if you’ve opened a text editor or you have a pen in your hand you’ve successfully completed step one. Now, what do you write? I like to start with the five W’s:

Whom?

  • Does your game appeal to a specific age range or interest group or gender or even ethnic background?
  • Will you have a large audience your game will appeal to or a small audience?
  • What are the benefits and downsides of the audience you’ve identified?

What?

  • What kind of game are you trying to make?
  • What programming language best suits this kind of game?
  • Does it fit into a specific genre of game or does it span multiple genres?
  • Does it embody a completely new genre?
  • Can you find other games that are similar to the game you are trying to make? If so, what do these games do well and where do fall short?
  • Are there lots of other games on the market similar to the type of game you’re trying to make?
  • What will your charge for your game?
  • What do other, similar games of this type charge?
  • What are the benefits and downsides of the type of game you’re trying to make?

Where?

  • Where does your game take place?
  • What kind of maps or features or environment are unique to your game?
  • What are the benefits and downsides of where your game takes place?

When?

  • When will you have time to work on this game?
  • When can you start this game?
  • When can you fund the development of this game?
  • What are the benefits and downsides of developing this game?

Why?

  • Why are you making this game?
  • Why is your game unique?
  • Why will your game stand out from the crowd?
  • Why will people choose to play your game over other similar games?
  • Why will people pay for your game?
  • What are the benefits and downsides of making this game?

3. Make A Design Document

Your design document is a refined version of everything you’ve written down in step 2. Go back and really analyze what your goals for the game are and if what you’ve written down makes sense in the larger picture. Sometimes a good idea you have for one area of the game will conflict or make another part of the game tedious, uninspired or downright frustrating. For a game design document I like to use the following format:

  1. Intro
    • What is the vision for your game and a short description of how the game is played
  2. Audience, Platform & Marketing Strategies
    • Who the game is for, what platforms you’re making it for and what sets your game apart that will make it marketable and different from others
  3. Core Gameplay & Mechanics
    • How the game is played including physics, rules and limitations
  4. Characters
    • What characters are in your game including what they look like, their names and backgrounds and personalities
  5. Story, Themes & Twists
    • If your game has an overarching story then you’ll outline your plot and how the game progresses with the story line
  6. World
    • Describe the world your game is set in, including maps and locations and their purpose or importance
  7. Assets
    • All the different images, music, animations, etc that you will need to have a fully functional game
  8. Technical Specs
    • What language you’re using, how games are loaded/saved, where games are stored, the number of servers you’ll need and anything else relating to the technical setup of your game
  9. Interface
    • What the game interface looks like and how the player will interact with it
  10. Outside References
    • Articles, links, design inspriations, or anything else that you’re using as a reference for the game you’re making
  11. Appendix
    • Code style guidelines, dictionary of terms, and anything else that is important for understanding your design document that may not necessarily relate to your game directly

Once you’ve fully fleshed out your game design by going into depth about the features, physics, economy, weapons, characters and how the game works it’s time to break it down. Start by creating lots of of small, easy tasks you can accomplish in order to see your core game mechanics to completion enough that you could play a simple version of your game without any extra bells and whistles. Set yourself up to do as little as you have to but as much as you need to in order to get a really simplified, yet completed, version of your game.

PHP Tutorial: Cookies vs Sessions

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If you’re interested in making any kind of web based application then learning how to use sessions and cookies is a must. Many people don’t understand how these work and how they different from each other, and why you would choose to use one versus the other. So put on your thinking caps and let’s get started.

What is a Cookie?

A cookie is a data file that’s written to your browser’s localStorage with data you want to keep track of for a user. So what’s localStorage? The best real world analogy I can give you is to think about it like a 3 ring binder that you can add, update and remove files from. In this example a cookie would be a piece of paper in your 3 ring binder.

How Do Cookies Work?

When you navigate around the Internet your browser is constantly sending and receiving information from the websites you want to access. These are called HTTP headers. HTTP headers contain important information about the requests and responses being sent back and forth from a browser to a server. When someone has an active cookie from your website in their browser’s localStorage it automatically passed in the HTTP headers to the site of origin in the $_COOKIE variable of PHP. Since headers have to be sent before any output setting a cookie must always go at the top of your file.

How do I Create a Cookie?

<?php
$name = "myCookie";
$value = "hello world!";
$expires = time() + 60 * 60 * 24; //1 day
$path = "/";
$domain = "yourwebsite.com";
$secure = 0; //0 for false, 1 for true
$httponly = 0; //0 for false, 1 for true

//let's tell the browser to create our cookie
setcookie($name, $value, $expires, $path, $domain, $secure, $httponly);

//let's make a cookie array too
setcookie("cookieArray[0]", "A");
setcookie("cookieArray[1]", "B");
setcookie("cookieArray[2]", "C");

//you must refresh the page before your new cookies are visible
echo "refresh the page to see your cookies: " . $_COOKIE['myCookie'];

//this will loop through and display your array cookies
foreach ($_COOKIE['cookieArray'] as $key => $value)
{
 echo "<br/>array cookie $key => $value";
}
?>

In this first example we’ve created a cookie called myCookie that stores the value of hello world! In order to see something printed on the screen you must refresh the page. This is because the HTTP headers must be sent from the server to your browser and then from your browser back to the server before they show up in the $_COOKIE variable.

Expires is an optional value that tells the browser how long to keep our cookie before it deletes it. By using the current time() and then adding on an extra 24 hours our cookie will only stick around for a day before the browser deletes it. So in this example if your cookie is created at today at 12noon EST it will expire tomorrow at 12noon EST. When your cookie is expired you’ll have to create a new one if you want to store your $value again.

Next we’ve set a path for our cookie. This is also an optional field and will default to / if you don’t give it a value. This tells the browser where this cookie will be available. So let’s say your website is http://yourwebsite.com and you only want this cookie to be available when you’re inside the http://yourwebsite.com/users/ section or your website. If that were the case we’d change the path to /users/ and then our cookie will only be accessible when we’re in the users directory. When we leave the path at / it means our cookie is available on any part of the domain we’ve given it.

The domain of your cookie is optional. If you don’t provide a domain for your cookie it may default to your current domain name. You can also set your domain name to a subdomain. So for instance, if we had a subdomain of http://users.yourwebsite.com we would set our domain to users.yourwebsite.com then our cookie would only be available when we’re inside our users subdomain.

The secure section of the cookie is optional and should only be set to true if you’re using https.

The httponly is optional and tells newer browser to only make your cookie accessible in the HTTP header. Not all browsers support this functionality, however it has been added to help prevent against cross site scripting (XSS) attacks.

How do I Access Cookie Values?

<?php
//this shows you a single cookie
echo $_COOKIE['myCookie'];

//this shows you all available cookies
print_r($_COOKIE);
?>

Once you have a cookie set you can access it by using the $_COOKIE variable in PHP and then pass it the name of the cookie you want to access or you can use a print_r() call to print all available cookies.

How do I Delete a Cookie?

<?php
//unset the single cookie
unset($_COOKIE['myCookie']);

//unset the array cookies
unset($_COOKIE['cookieArray']);

//update the cookie's expiration date to sometime in the past
setcookie("myCookie", false, time()-1);
setcookie("cookieArray[0]", false, time()-1);
setcookie("cookieArray[1]", false, time()-1);
setcookie("cookieArray[2]", false, time()-1);
?>

Sometimes you want to remove a cookie. There are two different ways to do this. The first is to unset() the cookie and the second is to update the expiration date to a time in the past which will force your browser to remove it. Just like when we set a cookie, you must refresh the page before you will see that your cookie has been removed.

How do I Edit a Cookie?

<?php
//to edit a single cookie value
setcookie("myCookie", "My new value");

//to edit a cookie array
setcookie("cookieArray[0]", "one");
setcookie("cookieArray[1]", "two");
setcookie("cookieArray[2]", "three");
?>

As long as the cookie exists all you need to do is set the cookie with the same name and give it a different value. You won’t see that the values in your cookie have changed until you refresh the page since cookies are sent in an HTTP header.

Cookie Trouble Shooting

  • If you’re having trouble setting a cookie and you’re getting a headers already sent error then you have some kind of output (text, spaces, html, images, etc) that are being displayed to the screen before you’re calling your setcookie() function.
  • Once you’ve added, edited or deleted a cookie you must refresh the page before you can see that your changes have taken place. This is because cookies are sent in HTTP headers.
  • Cookies must be deleted with the exact same parameters as they were set with.
  • Cookie arrays are stored as one file for each index in the array. For this reason large arrays are not recommended. If you need to store lots of data in a cookie it’s more useful to use a single cooke and concatenate the values with implode() then retrieve the data  using explode().
  • If one of the values in your cookie resolves to a false your cookie will be deleted. For this reason you shouldn’t use true/false booleans but instead use 0 and 1.
  • It is not recommended to serialize your cookie values as this can cause security holes.
  • If the user’s browser has cookies disabled or will not allow cookies to be stored then you won’t be able to create a cookie in their localStorage. This problem gave rise to the creation of sessions.

What Is a Session?

Sessions are the best solution for short term storage of data and dealing with user’s browsers that don’t allow the creation of cookies. Sessions will attempt to create a cookie and if the attempt fails will instead propagate via the URL. However a session will only persist over the duration of a user’s visit on your website. Once the user leaves your site the cookie (if one was created) is deleted so there is no persistent information retained about the user in the browser’s localStorage once they’ve left your website.

How do I Create a Session?

<?php
//you have to start the sessions before you can use them
session_start();

//set a single session value
$_SESSION['mySession'] = "hello world!";

//set an array in a session
$_SESSION['myArray'] = new array('A', 'B', 'C');

//set an object in a session
$_SESSION['myObject'] = new myObject();
//this tells php your done making changes to the session
session_write_close();

//session values are immediately available
echo $_SESSION['mySession'];
print_r($_SESSION['myArray']);
print_r($_SESSION['myObject']);
?>

All sessions must be started with the session_start() call unless you have them set to auto start in your php.ini file. Usually this isn’t the case with most hosting providers. In addition session_start can take parameters to configure the length of the session and the storage location, etc, however most hosting providers don’t let you change these settings so I won’t cover them here.

Sessions are sent via HTTP headers just like cookies are (when PHP tries to create a temporary cookie), however since they can persist without cookies the data is immediately accessible once it has been initialized. This means you won’t have to refresh the page to access the data you’ve stored in them.

How do I Access Session Values?

<?php
session_start();

echo $_SESSION['mySession'];
print_r($_SESSION['myArray']);
print_r($_SESSION['myObject']);
?>

Unlike cookies where you have to refresh the page before you can access them, session values are immediately available once they’ve been set. All you have to do is start the sessions (unless sessions have been set to auto start) and then look for the name of the session you want to access.

How do I Delete a Session?

<?php
session_start();

//remove a single session values
unset($_SESSION['mySession']);
unset($_SESSION['myArray']);
unset($_SESSION['myObject']);

//alternative way to remove a session values
$_SESSION['mySession'] = false;
$_SESSION['myArray'] = null;
$_SESSION['myObject'] = '';
//this tells php your done making changes to the session
session_write_close();

//remove all session values
session_destroy();
?>

The best way to remove a session is to unset it, however you can also set the value to falsey or call session_destroy() to remove all session values.

How do I Edit Session Values?

<?php
//you have to start the sessions before you can use them
session_start();

//edit a single session value
$_SESSION['mySession'] = "new value!";

//edit an array in a session
$_SESSION['myArray'] = new array('one', 'two', 'three');

//edit an object in a session
$_SESSION['myObject'] = new myNewObject();

//this tells php your done making changes to the session
session_write_close();

//session value changes are immediately available
echo $_SESSION['mySession'];
print_r($_SESSION['myArray']);
print_r($_SESSION['myObject']);
?>

You can edit session values the same way you set them initially.

Session Troubleshooting

  • If you’re having trouble getting a session started and you’re getting  headers already sent errors then you have some kind of output (text, spaces, html, images, etc) that are being displayed to the screen before you’re calling your start_session() function.
  • Sessions will only last for the duration of a user’s visit or for the session_expiration time that’s set in the php.ini file. You can learn more about session configuration values in the PHP manual.
  • Make sure you’re not doing an unset($_SESSION) as this will make it impossible to register any new values in the $_SESSION.
  •  You can’t use reference variables in sessions.
  • If register_globals are enabled they will overwrite variables with the same $_SESSION name. For instance if you have a session named mySession and register_globals is enabled and you create a $mySession variable it will overwrite the $_SESSION[‘mySession’] value with whatever you’ve assigned to $mySession.
  • If you’re having a problem changing values in your session make sure you’re calling session_write_close() after you’ve made changes to session values. This is especially important if you’re doing a lot of asynchronous ajax calls.

Should I Use a Session or a Cookie?

The best way to answer this question is do you need data on a user to persist once they’ve closed their browser? Sessions will only last for the duration of a user’s visit on your website, they will disappear as soon as the user has closed all windows and tabs that they have open for your website. Cookies, on the other hand, will remain on a user’s computer until the user removes them from their browser or they expire.

Pros & Cons of Sessions vs Cookies

Type Pros Cons
Sessions Excellent for short term data storage

Can access immediately after initialization

Will create a temporary cookie if cookies are enabled/supported, otherwise propagated on the URL

Can be used for authentication

Only last for the duration of the user’s visit

Susceptible to XSS attacks

Cookies Excellent for long term storage of data

Can be used for authentication

Must be enabled/supported on the browser

Must refresh the page before you can access cookie data

Susceptible to XSS attacks

MySQL Tutorial: Archiving and Loading Archived Table Data

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Let’s say you have a really large table and you want to archive the data to a new table so that your main table is smaller again. This is useful with things like chat logs or game logs which grow large really quickly but you don’t want to lose the data or you want to keep a history of it. Making an archive table from the main table allows you to truncate the main table for faster queries.

Create the Archive Table

If you want to save the contents of the table into another archive table you’ll need to create a copy of the original table with all the same indexes and schema:

CREATE TABLE your_new_archive_table LIKE the_table_you_want_to_archive;

Dump the Data into the Archive Table

Now you have an archive table that matches your original table let’s dump the data into it:

INSERT your_new_archive_table * FROM the_table_you_want_to_archive;

Dump the Data into a SQL file

If you prefer to save your data to a file on the server rather than in another table you can archive it this way instead. Make sure your file has saved and has data in it before you truncate your original table.

SELECT * FROM the_table_you_want_to_archive INTO OUTFILE '/save_path/your_new_archive_table .sql';

Test the Archive Table

Make sure your table has data in it by looking at your new archive table:

SELECT * FROM your_new_archive_table LIMIT 100;

Test the Archive File

Go to the command line and check to make sure you file was created and has data in it by typing the following:

cat /save_path/your_new_archive_table.sql

Empty the Original Table

Make sure your archive table or archive file has data in it before you empty your original table.

TRUNCATE TABLE the_table_you_want_to_archive;

Load an Archive Table Back Into the Original Table

If you decide you want to load your archived data back into the original table you can do the following.

INSERT the_table_you_want_to_archive * FROM your_new_archive_table;

Load an Archive File Back Into the Original Table

Once you have an archive file you can load it back into your database by doing the following:

LOAD DATA INFILE '/save_path/your_new_archive_table.sql' INTO TABLE the_table_you_want_to_archive;

PHP Tutorial: Run Multiple Tic-Tac-Toe Game Instances (no database required)

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Someone asked me about this in a comment recently so this post is specifically for you but I’m sure there are other people who will benefit from it as well. If you haven’t read the tic-tac-toe game tutorial yet then you’ll need to start there. This tutorial assumes you’ve already completed that and now you want to run two or more tic-tac-toe boards on the page simultaneously.

Or if you want to skip this tutorial you can
download the source code or try the working example

Concepts

The neat thing about classes is that you can use them to create multiple instances with varying states and data even though they all have the same methods and properties. Think about a monster RPG game. Each monster has a different name and breed and picture and strength — but they all have those things in common even though the values are different. Our tic tac toe class works the same way, we can create multiple instances of the game and they’ll each have different states — whose turn it is, which places on the board are filled — but they’ll all work the same way. In order to run multiple instances of our tic tac toe games we’re going to have to update our games so they can be uniquely identified by an instance number. The reason for this is so that when you play the game on instance 1 we know you want to update the state of instance 1 when you submit the form. If we didn’t give each game it’s own instance identifier then every time you made a move on one board it would reflect that move on all instances of the board at the same time.

Creating The Instance Form

Let’s change our index file so that we’re allowing the user to choose how many instances of the game they want to play. We start by removing where we created a new game from the top of the file. Since we want multiple instances we need to create the new game for every instance we have and since we don’t know how many instances we have at this point it needs to move down in our code base. Now once the user has selected how many instances of the game they want to play we need to dynamically generate that many. Using a for loop we loop through the number of instances they selected and create a game for each of those instances in our new $_SESSION[‘game’] array. Before this was only a single game, making it an array means we now have multiple games in our game session variable. Finally we create a new game instance and tell it to start playing. This is what our new index file looks like.

<?php
/***
* File: index.php
* Author: design1online.com, LLC
* Created: 4.6.2015
* License: Public GNU
* Description: PHP/MySQL Version of 2 Player Tic Tac Toe
* that allows playing multiple instances of the game at the same time
***/
require_once('oop/class.game.php');
require_once('oop/class.tictactoe.php');

//this will store their information as they refresh the page
session_start();

define('MAX_INSTANCES', 5); //the maximum number of games they can play at the same time

//trying to set number of instances to play
if (isset($_POST['instances'])) {
 if (is_numeric($_POST['instances']) && $_POST['instances'] > 0) {
 $_SESSION['instances'] = $_POST['instances'];
 }
}

?>
<html>
 <head>
 <title>Tic Tac Toe - Multiple Instances</title>
 <link rel="stylesheet" type="text/css" href="inc/style.css" />
 </head>
 <body>
 <div id="content">
 <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
 <h2>Let's Play Tic Tac Toe!</h2>
 <?php
 //we need to know how many instances to create
 if (!isset($_SESSION['instances'])) {
 ?>
 <p>How many games would you like to instantiate?</p>
 <select name="instances">
 <?php
 for ($i = 1; $i <= MAX_INSTANCES; $i++) {
 echo "<option value=\"$i\">$i</option>";
 }
 ?>
 </select>
 <input type="submit" name="submit" value="Let Me Play!" />
 <?php
 } else {
 echo "<table width=\"100%\">
 <tr>";
 
 for ($i = 1; $i <= $_SESSION['instances']; $i++) {
 
 //if they haven't started a game yet let's load one
 if (!isset($_SESSION['game'][$i]['tictactoe'])) {
 $_SESSION['game'][$i]['tictactoe'] = new tictactoe($i);
 }
 
 echo "<td>";
 
 //play the game passing it the game data for that instance
 $_SESSION['game'][$i]['tictactoe']->playGame($_POST);
 
 echo "</td>";
 }
 
 echo "</tr>
 </table>";
 }
 ?>
 </form>
 </div>
 </body>
</html>

Adding Instances To The Class

The first thing we need to do is add an instance identifier to our tictactoe class. Since we need to know which game the player is trying to play adding a $this->instance value to our class will let us keep track of which game is which. Once that’s done we update our checks for $_POST data to make sure we’re using the correct data for the correct instance. Voila! Our games now only update when they see $_POST data that pertains to them. Our new tictactoe class file looks like this:

<?php
/***
* File: oop/class.tictactoe.php
* Author: design1online.com, LLC
* Created: 1.31.2012
* License: Public GNU
* Description: tic tac toe game
***/

class tictactoe extends game
{
 var $instance = 0; //the instance of this game
 var $player = "X"; //whose turn is
 var $board = array(); //the tic tac toe board
 var $totalMoves = 0; //how many moves have been made so far 

 /**
 * Purpose: default constructor
 * Preconditions: none
 * Postconditions: parent object started
 **/
 function tictactoe($instance)
 {
 /**
 * instantiate the parent game class so this class
 * inherits all of the game class's attributes 
 * and methods
 **/
 $this->instance = $instance;
 game::start();
 
 $this->newBoard();
 }
 
 /**
 * Purpose: start a new tic tac toe game
 * Preconditions: none
 * Postconditions: game is ready to be displayed
 **/
 function newGame()
 {
 //setup the game
 $this->start();
 
 //reset the player
 $this->player = "X";
 $this->totalMoves = 0;
 
 //reset the board
 $this->newBoard();
 }
 
 function newBoard() {
 
 //clear out the board
 $this->board = array();
 
 //create the board
 for ($x = 0; $x <= 2; $x++)
 {
 for ($y = 0; $y <= 2; $y++)
 {
 $this->board[$x][$y] = null;
 }
 }
 }
 
 /**
 * Purpose: run the game until it's tied or someone has won
 * Preconditions: all $_POST content for this game
 * Postconditions: game is in play
 **/
 function playGame($gamedata)
 {
 if (!$this->isOver() && isset($gamedata[$this->instance . 'move'])) {
 $this->move($gamedata);
 }
 
 //player pressed the button to start a new game
 if (isset($gamedata[$this->instance . 'newgame'])) {
 $this->newGame();
 }
 
 //display the game
 $this->displayGame();
 }
 
 /**
 * Purpose: display the game interface
 * Preconditions: none
 * Postconditions: start a game or keep playing the current game
 **/
 function displayGame()
 {
 
 //while the game isn't over
 if (!$this->isOver())
 {
 echo "<div id=\"board\">";
 
 for ($x = 0; $x < 3; $x++)
 {
 for ($y = 0; $y < 3; $y++)
 {
 echo "<div class=\"board_cell\">";
 
 //check to see if that position is already filled
 if ($this->board[$x][$y])
 echo "<img src=\"images/{$this->board[$x][$y]}.jpg\" alt=\"{$this->board[$x][$y]}\" title=\"{$this->board[$x][$y]}\" />";
 else
 {
 //let them choose to put an x or o there
 echo "<select name=\"{$this->instance}_{$x}_{$y}\">
 <option value=\"\"></option>
 <option value=\"{$this->player}\">{$this->player}</option>
 </select>";
 }
 
 echo "</div>";
 }
 
 echo "<div class=\"break\"></div>";
 }
 
 echo "
 <p align=\"center\">
 <input type=\"submit\" name=\"{$this->instance}move\" value=\"Take Turn\" /><br/>
 <b>It's player {$this->player}'s turn.</b></p>
 </div>";
 }
 else
 {
 
 //someone won the game or there was a tie
 if ($this->isOver() != "Tie")
 echo successMsg("Congratulations player " . $this->isOver() . ", you've won the game!");
 else if ($this->isOver() == "Tie")
 echo errorMsg("Whoops! Looks like you've had a tie game. Want to try again?");
 
 echo "<p align=\"center\"><input type=\"submit\" name=\"{$this->instance}newgame\" value=\"New Game\" /></p>";
 }
 }
 
 /**
 * Purpose: trying to place an X or O on the board
 * Preconditions: the position they want to make their move
 * Postconditions: the game data is updated
 **/
 function move($gamedata)
 { 

 if ($this->isOver())
 return;

 //remove duplicate entries on the board 
 $gamedata = array_unique($gamedata);
 
 foreach ($gamedata as $key => $value)
 {
 if ($value == $this->player)
 { 
 //update the board in that position with the player's X or O 
 $coords = explode("_", $key);
 
 //make sure we use the data from the right instance
 if ($coords[0] == $this->instance) {
 $this->board[$coords[1]][$coords[2]] = $this->player;

 //change the turn to the next player
 if ($this->player == "X")
 $this->player = "O";
 else
 $this->player = "X";
 
 $this->totalMoves++;
 }
 }
 }
 
 if ($this->isOver())
 return;
 }
 
 /**
 * Purpose: check for a winner
 * Preconditions: none
 * Postconditions: return the winner if found
 **/
 function isOver()
 {
 //top row
 if ($this->board[0][0] && $this->board[0][0] == $this->board[0][1] && $this->board[0][1] == $this->board[0][2])
 return $this->board[0][0];
 
 //middle row
 if ($this->board[1][0] && $this->board[1][0] == $this->board[1][1] && $this->board[1][1] == $this->board[1][2])
 return $this->board[1][0];
 
 //bottom row
 if ($this->board[2][0] && $this->board[2][0] == $this->board[2][1] && $this->board[2][1] == $this->board[2][2])
 return $this->board[2][0];
 
 //first column
 if ($this->board[0][0] && $this->board[0][0] == $this->board[1][0] && $this->board[1][0] == $this->board[2][0])
 return $this->board[0][0];
 
 //second column
 if ($this->board[0][1] && $this->board[0][1] == $this->board[1][1] && $this->board[1][1] == $this->board[2][1])
 return $this->board[0][1];
 
 //third column
 if ($this->board[0][2] && $this->board[0][2] == $this->board[1][2] && $this->board[1][2] == $this->board[2][2])
 return $this->board[0][2];
 
 //diagonal 1
 if ($this->board[0][0] && $this->board[0][0] == $this->board[1][1] && $this->board[1][1] == $this->board[2][2])
 return $this->board[0][0];
 
 //diagonal 2
 if ($this->board[0][2] && $this->board[0][2] == $this->board[1][1] && $this->board[1][1] == $this->board[2][0])
 return $this->board[0][2];
 
 if ($this->totalMoves >= 9)
 return "Tie";
 }
}

Conclusion

Try the working example! In this tutorial we talked about instances and how you can use a class to dynamically create multiple instances each of which keep track of their own state and values. If you’ve been following my game tutorials then I hope you’re starting to see how powerful classes are and how iterative improvements can be used to enhance your gameplay, functionality and user experience.

Angular JS Tutorial: Difference between ng-hide and ng-if

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It took me a while to even realize that there were two different ways toggle the display of HTML DOM elements with Angular JS — thank you Angular docs for not being nearly as helpful as you were when you had comments. Anyways (rant over), this is a really good thing to know because it will help you use the power of Angular to the fullest.

Ng-Show and Ng-Hide

These are use for when you want to toggle the visibility of a DOM element and that toggle can happen any number of times. This is like adding css styles for display. When ng-show is true the css display style is set to block/inline. When ng-show is false the css display style is set to none. Conversely if you use ng-hide instead when ng-hide is set to true display is none and when ng-hide is set to false display is block/inline. The DOM elements are always present no matter if the content is visible or not.

So, now for a good example using ng-show. Let’s say you only want to show a message to someone once they’ve entered their name:

<label for="nameInput">Enter Your Name:</label>
<input type="text" id="nameInput" ng-model="name" />

<div ng-show="name">
  <p>Hello {{name}}, it's nice to meet you!</p>
</div>

This also works using ng-hide, if there’s no name then we don’t want to show our greeting:

<label for="nameInput">Enter Your Name:</label>
<input type="text" id="nameInput" ng-model="name" />

<div ng-hide="!name">
  <p>Hello {{name}}, it's nice to meet you!</p>
</div>

Ng-If

So now let’s harness the power of Angular JS. If you have a DOM element that you ONLY want to display/hide once — like say when the page first or view first loads — then this is the option for you. Ng-If either adds or removes the DOM element from the DOM. When Ng-If is true then DOM element will be added to the document tree. When Ng-If is false the DOM element will be completely removed from the document tree. Why is this a good thing? This means your page will load faster because your document tree doesn’t have to render and then hide DOM elements that you’re never going to use.

Let’s pretend we have a data object like containing the first and last name of some famous people. We want to display this information in a table. However the data in our object comes from a query to a database — so we might not always have results to display. This is where Ng-If is really handy. Take a look at this example where if we have no results in our data object then our table HTML will be completely removed from the DOM — therefor making it faster — before angular renders the view:

<div ng-if="data.length > 0">
  <h4>Famous People</h4>
  <table>
    <tr>
      <th>First Name</th>
      <th>Last Name</th>
      <th>Phone Number</th>
      <th>Email</th>
    </tr>
    <tr ng-repeat="person in data">
      <td>{{person.firstName}}</td>
      <td>{{person.lastName}}</td>
      <td>{{person.phone}}</td>
      <td>{{person.email}}</td>
    </tr>
  </table>
</div>