Lesson 6 - Validators

Why Should I Validate My Page

There are a LOT of different reason why you should validate your HTML documents. The following is quoted from http://www.awpa.asn.au/html/validate.html:

You may think that if you make a mistake it will be obvious when you look at the page in your browser. However, browsers are deliberately designed to recover from errors in markup. In one way this is very desirable, because it often means that even badly marked up documents are viewable.

On the other hand, you cannot be sure how different browsers (or even different versions of the same browser) will recover from a particular error. Validation will help future-proof your documents.

1. It is the best way to be assured that your page is rendered similarly in all browsers.
2. It will help you find the reason why part of the page is missing. (You may not have seen this one yet, but when you do you'll understand.)
3. One of the best ways to learn HTML.
4. Helps to find "misspellings" in tags and in attributes. But remember validators will not "spell check" your actual document.
5. Remember that you are writing a webpage to convey information. The best way to make sure that as many people as possible have access to that information is by using valid HTML.
6. And once again, it will future-proof your document. Forgetting a quotation symbol in your current browser may not have any effect, but in the next version, it renders the page useless.

How to Validate Your Page

You actually have 2 options, basically they are online or offline validation. Each on offers it's own benefits, but since you should have downloaded Tidy! in lesson 1 (or at least a HTML editor with Tidy! built in), then we are going to focus on using an offline validator.

Online Validators

The main benefit to using online validators is that you never have to worry about outdated software. The big drawback is that you must get online to use it. And if your like me and connect with a modem with only one phone line in the house, it is not very convenient.

There are a lot of different validators online, but two that I find to be worth using. One is W3C's validator. Who better to check your HTML document the the organization responsible for the web? The other one is Bobby. Bobby is not really a validator, but a service that check your HTML document for any significant barriers to access by individuals with disabilities. Since we work for a public school, I would hope that everyone would want to make their page as accessible as possible to those students with disabilities. Besides the fact that it is basically against the law. (Americans With Disabilities Act, and more recently Section 508 of the Rehabilitation Act Amendments of 1998)

Offline Validators

The benefit to an offline validator is that it is always available. The bad thing is that it can become out-of-date very quickly. For me, the benefit here certainly out weighs the drawbacks. In lesson 1 I had you download either an HTML editor with Tidy! built in or a stand-alone version of Tidy!. Tidy is the only validator that I know of that is open source, and therefore consistently up-to-date, and available for numerous computer platforms. Unfortunately, it does not come with much documentation. (One reason is that it is really simple to use). All that aside, here I am to help you - please choose which operation system you are using Tidy! on:

• I am using Macintosh
• I am using Windows
• I am using Linux