Real world example of Polymorphism
OOPS is easy to understand and is most confusing concept. When I interview I usually ask my favorite question, real world example of polymorphism. I have met just one or two candidates who came up with an answer. Today was the day I met another candidate. As usual, I was expecting a formal or a normal reply. But…
Me: Can you give me a real world example of polymorphism?
Candidate: 
I can say I am an example of polymorphism, yes I am an example of polymorphism, you see, I am a son for my parents, am a nephew and of course am a boyfriend for my girlfriend…
Why the hell he he stressed upon his being a boyfriend. Showoff?
Error Reporting
PHP has come a long way. I used to program with Global vars then $HTTP_POST_VARS and then $_POST and even did a foreach to convert all Posted/Get-ed vars to their respective variable names. But I never faced any issue till the time I started using error_reporting(E_ALL).My life changed. Initially I started pulling my hairs and then I realised that I will be bald very soon and then started concentrating on writing better code. Avoiding on the fly variables. Yesterday at work, I again realised the value of
error_reporting(E_ALL).I created a small piece of code and tested it in a temp php file. It looked superb. I ported the code to production environment and it started breaking. I thought for a while. May be I have introduced some parse errors. I ran a php -l test and didnt see any syntax error. I read the whole code line by line. Even did a diff. Still the temporary php code was running fine and the code in production environment was not working fine. 
I decided to look at the code bit later. After a break of 15 minutes I decided to write a unit test and capture everything. And then I found a notice message telling me I was accessing an index that didn’t exist. I looked at my data set. It was a long range of number, 6184 to be precise and an index value 280 was not set. I looked at my temp file and found my code was not going thru error reporting and production environment was set up to halt at all notices and warnings. Damn it!
Drop down menus with jQuery
After attempting sliding menus with jQuery I developed drop down menus using lists.
Here is the code
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html> <head> <title>Drop Down Menus With jQuery</title> <script type="text/javascript" src="js/jquery.js“></script> <script type=”text/javascript”> function mainmenu(){ $(”#nav ul” ).css({display: “none”}); // Opera Fix $(”#nav>li” ).hover( function(){ $(this).find(’ul:first’).css({visibility: “visible”,display: “none”}).show(400); }, function(){ $(this).find(’ul:first’).css({visibility: “hidden”}); }); } $(document).ready(function(){ mainmenu(); }); </script> <style type=”text/css”> #nav, #nav ul{ margin:0; padding:0; list-style-type:none; list-style-positionutside; position:relative; } #nav>li{ float:left; position:relative; } #nav>li>a{ font-size:12px; font-family: arial; color:#000000; padding:5px; text-decoration:none; border: 1px solid #ddd; background:#eee; } #nav ul { position:absolute; dispay:none; } #nav a{ display:block; } #nav>li>ul>li>a{ font-size:12px; font-family: arial; color:#000000; padding:3px; text-decoration:none; border: 1px solid #aaa; background:#bbb; } </style> </head> <body> <ul id=”nav”> <li><a href=”">HTML</a></li> <li><a href=”#” >CSS</a> <ul> <li><a href=”#”>CSS 1</a></li> <li><a href=”#”>CSS 2</a></li> <li><a href=”#”>CSS 3</a></li> </ul> </li> <li><a href=”#” >Javascript</a> <ul> <li><a href=”#”>Mootools</a></li> <li><a href=”#”>Prototype</a></li> <li><a href=”#”>jQuery</a></li> <li><a href=”#”>Yahoo! UI</a></li> <li><a href=”#”>Dojo</a></li> <li><a href=”#”>Mochi Kit</a></li> </ul> </li> </ul> </body> </html>
Sliding menus with Jquery
I have been avoiding Jquery for quite some time. I was just turning myself blind to Jquery. Jaquery? What Jquery?
Damn it! I have been spelling jQuery as Jquery. 
I wanted some thing similar to accordion effect. There are tons of JavaScript frameworks offering this but I didnt want myself to be again copying huge/minified file/s and then reading hell lot of documentations figuring out how and why and ….
Phew 
Now following is a snippet of code from my dear Kaddu. Obviously you will need jQuery.
<html> <head><title>Tree</title> <script type="text/javascript" language="javascript" src="js/jquery.js“></script> <script type=”text/javascript” language=”javascript”> $(document).ready(function(){ $(’.level-1′).hide(); $(’.top’).css(’cursor’,'pointer’).bind(’click’,viewList); }); this.viewList = function (){ var id = $(this).attr(’id’); var spId = id.split(’_'); $(’#ul_’+spId[1]).slideToggle(); } </script> </head> <body> <ul> <li class=”top” id=”li_1″> 1 <ul class=”level-1″ id=”ul_1″> <li>1.1</li> <ol> <li>1.1.1</li> <li>1.1.2</li> <li>1.1.3</li> </ol> </ul> </li> <li class=”top” id=”li_2″> 2 <ul class=”level-1″ id=”ul_2″> <li>2.1</li> <ol> <li>2.1.1</li> <li>2.1.2</li> <li>2.1.3</li> </ol> </ul> </li> <li class=”top” id=”li_3″> 3 <ul class=”level-1″ id=”ul_3″> <li>3.1</li> <ol> <li>3.1.1</li> <li>3.1.2</li> <li>3.1.3</li> </ol> </ul> </li> </ul> </body> </html>
Now, you can change lis to divs to spans to ps or what not. You just need IDs and thats it. You have a sliding menu. 
Are design patterns silver bullets?
I hate text books thicker than half an inch. These books are, first hard to read, hard to understand. I am a man who will do it and understand it rather than read it and understand it. But today I decided to read and do and tried to understand. The object in question was a Frame Work which allowed me to build a SQLite based guestbook using MVC pattern, oops!, MVC Design Pattern. 
The question is do I really need to code more than 3 pages to develope a guestbook?
My answer is, no. Ofcourse you dont need a abstract knife factory which will give you a factory method that will let you create a kitchen knife to cut vegetables. I simply want to cut a piece of vegetable, say want to chop an onion to cook my ultimate Indian gravy dish. I need a knife. Now there are hell lot of knives in kitchen. Butcher knife, Kitchen knife, Chef’s knife and this and that and oh my god so many knives. So if I am planning to cook chicken dish I will need a butcher knife but also a kitchen knife to chop onions, green chillies and other stuff. So we have a abstract knife factory. Which in turn owns a factory method which in turns gives me an appropriate knife at the last momentdepending on what I am going to chopor cut.
Geez!!!
Come to procedural approach. I will develop a library of knives or say a knives holder. I will stack all my knives here and will pick up the knife which I need or say call the function whichever I need.
Aren’t design patterns leading to bloats or sometimes they turn into an overkill or…?
Are design patterns silver bullets?
