The following script is a single interface for pre-validating any HTML form. It lets you validate your form data the way you want, while handling the rudimentary tasks itself.

1) Change just one variable to make it work with $_GET or $_POST or $_REQUEST.

2) Name which elements are 'required' all at once in a hidden HTML text input.

3) Easily provide field descriptions in hidden HTML text inputs that you can use to print error statements.

4) Call a single function to print out error statements that you can easily style with CSS.

5) It automatically checks if fields marked 'required' have been filled out.

Most of the pre-validation code is from PHP 5: Unleashed by Sams Publishing. I found it extremely useful for a recent project. Sharing it here, I removed some unnecessary functions, and tried to simplify some points.

All the comments are my own; hopefully I provided more than enough explanation.

Remove all children of Object.

This is a version of my previous entrant, Promise, that will work with prototype, but does not require it. It's slightly more advanced, using .apply here and there.

It's basically a function to allow any other function to poll. Polling is generally regarded as bad practice in object oriented code, but can make very simple the matter of, for example, running a bit of code only after a single-run event (like onload) occurs (whether that be in the future or past), another unrelated bit of code needs to be hack-tracked, or any other generic condition.

Note that when the function runs, it doesn't necessarily run within the scope that's called it. Its context is set to itself, rather than its normal context, and it's asynchronous, so you'll not get a return value. If you use Prototype, you can bind the function and it'll behave as it should in terms of context, but I'm unaware of a way to cause an asynch function to block execution - and you'd really rather that not happen anyway, trust me.

Simple. It's parse_url, from PHP, implemented in Javascript. Seen a lot of similar ones around the web, but they were all bulky code and none of them took advantage of the RegEx parser in JS.

Applied as a member of the String prototype, so just call as myURL.parseURL(); Will return a named object with naming identical to that of PHP's function.

Additional: if first argument is present, will break the querystring up into name/value pairs, unescaped, and return that instead of the raw querystriing.

Prototype's Form.Methods library has a nice piece of code called 'serialize', which, if passed with the optional 'hash' parameter set to true, will convert an HTML form into a Javascript Object.

I was dismayed, however, to find that there was no way to reverse it; just as simply load a form using a Javascrip object.

So, here's one. enjoy.

This script performs reliable, cross-browser input autofocus that often can be used simply by dropping it in, with no modifications to the form or HTML body. It refuses to switch focus if it detects that the user has interacted with the form (avoiding a major source of annoyance with autofocus scripts) and correctly handles Firefox tabs opened "in the background", which most autofocus scripts fail on. Official home is on the Lost Souls MUD Grimoire.

A simple, flexible formula for generating diminishing returns out of input numbers. Full explanation and home, with sample calculators and versions of the code in other languages, on the Lost Souls MUD Grimoire.

These are some prototype methods to handle class names in html elements. As you all should know, a html element can have more than one class name.

This is part of my dom handling toolkit. Check it out and use it at will.

Cheers

This code allows you to set the "opcity" style attribute on a element without affecting it's content.

Just call the function for a specific element or to all elements of a given classname after the document loads.

Examples and advanced usage here...

This code snippet will validate an IP Address (IP v4).
return true if the ip address is valid. Else false.