January 2009 – Kavoir LLC

PHP: Checkbox Array in Form Handling – Multiple Checkbox Values in an Array

Checkboxes is probably one of the most frequently used form controls which come handy in dealing with one to many relationships. The multiple selective nature of HTML form checkboxes require a convenient way for PHP to process multiple checkbox values, ideally in a single array. By default, each and every HTML input control including checkboxes …

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.htaccess: Deny From All – Prohibit, Forbid or Restrict Directory Access

21 Comments / .htaccess Tutorials & Tips / By Yang Yang / January 27, 2009 October 27, 2010

Restricting directory access might be one of the most frequently used .htaccess techniques out there. As a site grows, there always are some areas that you don’t want visitors to look at such as merchandise warehouse where you store digital products for sale. You want a programmed server-side script to serve the download after confirming …

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.htaccess: Directory Listing — Enable Web Directory Browsing & Indexing

3 Comments / .htaccess Tutorials & Tips / By Yang Yang / January 27, 2009 October 27, 2010

One of the best things I love Apache web server is that it instantly enables you to share files and resources via plain web directory index listing without having to spend time making any fancy web pages to serve them. However, there are times when you need to hide things out. To disable web directory …

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PHP: Escape String Literals for SQL, mysqli::real_escape_string and PDO to Prevent SQL Injection Attacks

3 Comments / Information Security, PHP Tips & Tutorials, SQL / MySQL Tips and Tutorials / By Yang Yang / January 25, 2009 March 9, 2010

To successfully run a query with text data containing single quotes ‘ as well as other SQL reserved punctuations, AND to prevent SQL injections, you will always want to escape the text values before using them in a SQL query. In PHP 4.0, we are stuck with mysql_real_escape_string. With PHP 5.0, mysqli:prepare and mysqli::real_escape_string are …

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PHP: Prevent SQL Injection Attacks

7 Comments / Information Security, PHP Tips & Tutorials, SQL / MySQL Tips and Tutorials / By Yang Yang / January 25, 2009 March 9, 2010

SQL injection is a typical code injection attack that exploits weaknesses of application in the database layer. SQL injection vulnerability is created when one scripting or programming language is embedded in or used as input in another with failure to verify the legality or filter for potential dangerous codes. SQL injections are possible when input …

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Top 25 Most Dangerous Web Programming Errors, Loopholes and Bad Habits

1 Comment / Information Security, JavaScript Tips & Tutorials, PHP Tips & Tutorials, Programming Tips & Insights, SQL / MySQL Tips and Tutorials / By Yang Yang / January 22, 2009 January 2, 2010

As Web becomes one of the most fundamental means of communication and information delivery nowadays, and as its usage reaches population level in regards to that when the televisions prevailed, the protection of it has never been so critical. SANS institute in association with US government and various other weighty contributors, most of whom IT …

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HTML CSS Drop Down Menu Made Easy – SuckerFish Enhanced

2 Comments / CSS & HTML Tips / By Yang Yang / January 19, 2009 January 19, 2009

There’s a pure css drop down menu named SuckerFish published at ALA. Really straightforwardly clean code and simple drop menu script, however it might be friendlier for developers if it’s combined with the li:hover hack for IE6. The HTML: <ul id=”nav”> <li><a href=”#”>bodycare</a> <ul> <li><a href=”#”>lotions</a></li> <li><a href=”#”>creams</a></li> <li><a href=”#”>balms</a></li> <li><a href=”#”>butters</a></li> </ul> </li> <li><a …

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CSS selector:hover Hack for IE6

30 Comments / CSS & HTML Tips / By Yang Yang / January 19, 2009 January 19, 2009

IE 6 and lower versions of IE only implemented :hover for tag a. As per CSS 2.1 specification, all HTML tags / elements have :hover state so that when mouse pointer hovers over, different styles can be applied to them. li:hover is one of the frequent reasons why you need this hack. First, you have …

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Write and Run PHP with HTML

2 Comments / PHP Tips & Tutorials / By Yang Yang / January 19, 2009 January 19, 2009

Pure HTML is static text files with dead content that want everything but to change. However by the help of a service scripting language such as PHP, HTML can be dynamic and changes every time you make a different request to the server. PHP is born with HTML rendering in mind. So it’s plain easy …

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PHP: Run HTML as PHP

2 Comments / .htaccess Tutorials & Tips, PHP Tips & Tutorials / By Yang Yang / January 19, 2009 August 30, 2009

The last time I end up with hundreds of HTML files with PHP codes dispersed in them. Tried to rename them all to .php but failed. To use them and enable the php code within, I have to run the HTML files as PHP. How Apache web server works in resolving .php requests Apache gets …

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Create SQL Auto Increment Column (ID: Primary Key) in Table

5 Comments / SQL / MySQL Tips and Tutorials / By Yang Yang / January 17, 2009 January 17, 2009

With database development, a perfect data structure paradigm is that data records should all be uniquely distinguishable from each other. Therefore when you are designing and creating data fields or columns for an entity, you must always have an identifying column or field for each and every of the records stored in a table, enabling …

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PHP: File Upload Script (HTML Form + PHP Handler Class)

8 Comments / Free PHP Classes & Library, PHP Tips & Tutorials / By Yang Yang / January 15, 2009 March 1, 2010

It’s sometimes cumbersome to handle uploaded files — checking if it is really uploaded, moving and renaming. Why not writing all these chores into a class and make our own file upload script? First we are going to create a simple class to handle uploaded files and move them to some place we designate for …

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PHP: Resize Image and Store to File

28 Comments / Free PHP Classes & Library, PHP Tips & Tutorials / By Yang Yang / January 15, 2009 September 26, 2009

While there are a lot of methods for you to resize images with php, we will be using extension gd this time. Make sure you or your hosting company has installed it in the php distribution by running <?php if (extension_loaded(‘gd’)) { // return true if the extension’s loaded. echo ‘Installed.’; } else { if …

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Update your theme to WordPress 2.7 with Comments Threading and Paging

3 Comments / WordPress How To / By Yang Yang / January 15, 2009 January 15, 2009

Well dismiss me if I’m a little too late for this but just now I encountered this client who needs to update a wordpress theme, the comments section or comments.php to be precise, to accommodate some of the new features introduced in WordPress 2.7, comments threading and comments paging. The easy way — for new …

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HTML Form doesn’t upload the file?

CSS & HTML Tips / By Yang Yang / January 14, 2009 January 14, 2009

You had the <input type=”file” /> in place, however it just doesn’t seem to be uploading at all at the client side. After choosing a rather big file, the form submission and page reload finish in seconds, what’s wrong? Well, it’s almost certain that you have forgotten something. Try adding property enctype to <form>: <form …

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PHP4 Class – differences from PHP5

4 Comments / PHP Tips & Tutorials / By Yang Yang / January 14, 2009 January 14, 2009

Creating a rather simple custom CMS on my client’s server, everything seems ok until I start testing out some of my ready made proprietary PHP classes. The problem is that I make things in PHP5 and all the classes are in PHP5 format. Quickly searched and scanned through some old tutorials for PHP4 about creating …

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You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax …

PHP Tips & Tutorials, SQL / MySQL Tips and Tutorials / By Yang Yang / January 13, 2009 January 15, 2009

Scratching your head for a mystic error in your SQL query? No matter how you look into it, it just seems right and should by the God’s name work as you have wished. But it doesn’t and keeps pumping out annoying SQL syntax errors. Don’t panic, I have a few tips on this that might …

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PayPal Policy Update, 2009/01

1 Comment / PayPal & Ecommerce / By Yang Yang / January 13, 2009 January 13, 2009

PayPal is by far the most popular international merchant service. The newest update of their policies is carried out through the end of last year, 2008, and a lot of provisions are effective ever since. Some of the key points include: You may not use PayPal service for prohibited activities involving gambling, gaming and/or any …

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