Design KB: Website Scripting Topic

ActivePerl is the industry-standard Perl distribution, available for Windows, Linux, Mac OS X, Solaris, AIX and HP-UX. Developers worldwide rely on ActivePerl's completeness and ease-of-use, while corporate users protect their infrastructure and stay competitive with quality-assured ActivePerl business solutions.

Arrays in ASP Classic use a 0-based indice.

Use UBound to get the number of elements. UBound returns -1 if the array has no elements, 0 if it has 1, 1 if it has 2, etc.

ASP Classic is not case sensitive. My preference for all languages where case sensitivity does not matter is to use camel caps as in the first example above. Many developers coming from a case sensitive language prefer to use all lowercase.

In ASP, using ADO, you use RecordSet.AddNew to add a new record, Recordset.Update to post the record, and RecordSet.Delete to delete it. To edit a record, you open the RecordSet using an editable cursor.

In ASP Classic, you have to add an empty string to the value being compared in order to get consistent results. For example, add &"" to your string varilable or it's code equivalent &vbNullString. Then compare to an empty string or verify it's length to 0 with Len.

Languages Focus: Exception Trapping

A common usage of exception handling is to obtain and use resources in a "try-it" block, deal with any exceptions in an "exceptions" block, and release the resources in some kind of "final" block which executes whether or not any exceptions are trapped.

.asp is the default extension for Active Server Pages (ASP) although some developers will change the default extension in an effort to add an additional security level. Although there is no clear standard for include files, using .INC is common but you must make sure that .INC files are not executed nor displayed.

In ASP, using ADO, you filter a set of records using Filter.

In ASP, using ADO, you use Find and Seek to move a cursor of a RecordSet to a matching record.

By Reference or Value
For parameters, you can optionally specify ByVal or ByRef. ByRef is the default if you don't specify.

ASP uses MoveFirst, MoveLast, MoveNext, and MovePrevious to move a database cursor (a RecordSet).

In ASP, using ADO, you sort a set of records using the Sort property.

The following function demonstrates one technique for coding a Yes/No dropdown. It uses a for loop which can be expanded to handle more than the 3 states (Y, N, and blank).

Example of calling the function:

An associative array links a set of unique values (keys) to another set of values (not necessarily unique). Associative arrays are also known as a dictionary or a hash table in other languages.

There is a way to configure your ASP.NET website with one configuration for your internal development environment and another for your online website - and still be able to publish your site without hand editing the web.config.

When designing websites, all developers are required to manage not only the content of the site, but the indexing of the site as well.  Robots.txt is a powerful tool you can use to make sure your projects are listed in search engines as effectively as possible.

How do you find last Monday? I want to return a date for last Monday or today if today is Monday.

This article describes a technique I have used in JavaScript to print the contents of a web page in a neat and readable fashion. When site visitors try to print a page using CONTROL P or File then Print, the output on the printer is typically messy and illegible.

This article describes a technique I use in HTML to perform redirection to other web pages.

JavaScript is case sensitive. Change the case, and it no longer works! Notice the "W" in "Write" is capitalized.

Variable names are case sensitive.

Inhtml pages, you embed JavaScript code between <script> and </script> (see example). Also it's tradtional to put an HTML comment around your code too so that really old browsers don't crash (probably not all that important these days).

For JavaScript, Java, PHP, and C++, I prefer to put the first { at the end of the first line of the code block as in the example above because I see moreJavaScript codeformatted that way.

The JavaScript event handler contains events centered around the Document Object Model (DOM). Common events include onMouseOver and onMouseOut, onFocus and onBlur, onClick and onDblClick, onChange and onSelect, onLoad and onUnload.

For example, onMouseOver and onMouseOut are frequently used with websites to change an image when your mouse moves over it. The onClick event is used to trigger code upon a mouse click.

See "throw" to raise (throw) an error.

.js is the common standard for browser-side JavaScript and .jsp is the common standard for server-side JavaScript.

This article describes the JavaScript code I use to run a slideshow of images.

JavaScript does not offer a formal inheritance machanism. There are some tricks some developers are fond of.

Not fully OOP as you can call the method outside of the class.

Above returns "Mike P".

Notice JavaScript is 0 based (the first character is character 0).�0 is start character, 6 is number�of characters).�

You can also use substring where both numbers are indexes:

The following returns "re".

Perl assignment operators:

Commenting Code
Perl uses # for single line comments and Perl does NOT have a multiple line comment.

Compiler Directives (A special comment.)

Perl also uses compiler directives embedded in comments with #! as in:

In PHP, you declare constants using the define keyword:

Constants in PHP are case sensitive. A common standard in PHP is to use all-uppercase letters, with underscores to separate words within the name.

Perl uses subs and parameters are referenced in a special array. All arguments passed to a subroutine are stored in a special @_ array. To retrieve the arguments, you have to look inside the array and extract them.

Many developers just use a text editor but you have to be careful when developing on Windows and deploying to Unix/Linix. Some Windows text editors including Notepad, and Microsoft Expression Web save text files in UTF-8 which is not compatible with Unix/Linux.

There are many Perl editors available including ActivePerl Pro Studio, and the free Perl Express. I usually use Perl Express.

Quick Start: Install Perl to IIS or Apache, install Perl Express then configure to use Perl, then install MySQL. For IIS 7, you will likely have to configure Hangler Mappings and add %s %s.

In .PHPhtml pages, you embed PHP code between <?PHP and ?>.

For PHP, JavaScript, Java,and C++, I prefer to put the first { at the end of the first line of the code block as in the example above because I see morePHP codeformatted that way (and on PHP.Net).

PHP Alternative Syntax

Although I don't like to use it, PHP offers an alternative syntax for if, while, for, foreach, and switch. These code blocks are surrounded by statement ending keywords that all use End with camel caps such as endif, endwhile, endfor, endforeach,and endswitch.

In PHP, you declare constants using the define keyword:

Constants in PHP are case sensitive. A common standard in PHP is to use all-uppercase letters, with underscores to separate words within the name.

Many developers just use a text editor. There are many PHP editors available including phpDesigner, and Delphi for PHP.

Implements replaceAll in javascript. This is achieved using prototype.js

A quick comparison.

13 things you can do to make your code more secure, general advice about the rest of it, PLUS YOUR COMMENTS and experiences.

This article shows how PHP can be used to access a MySQL database to retrieve data for a scroll list. Here, I will discuss one that lists 12 rows at a time on a web page.