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How W3Schools Was Converted To XHTML ?

XHTML Interview Questions and Answers


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26. How W3Schools Was Converted To XHTML ?

W3Schools was converted from HTML to XHTML.
To convert a Web site from HTML to XHTML, you should be familiar with the XHTML syntax rules.
Your pages must have a DOCTYPE declaration if you want them to validate as correct XHTML.
The following DOCTYPE declaration was added as the first line of every page:
<!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">


Be aware however, that newer browsers might treat your document differently depending on the <!DOCTYPE> declaration. If the browser reads a document with a DOCTYPE, it might treat the document as "correct". Malformed XHTML might fall over and display differently than without a DOCTYPE.

Lower Case Tag And Attribute Names
Since XHTML is case sensitive, and since XHTML only accepts lower case HTML tags and attribute names, a general search and replace function was executed to replace all upper case tags with lowercase tags. The same was done for attribute names. We have always tried to use lower case names in our Web, so the replace function did not produce many real substitutions.

All Attributes Were Quoted
Since the W3C XHTML 1.0 Recommendation states that all attribute values must be quoted, every page in the web was checked to see that attributes values were properly quoted. This was a time-consuming job, and we will surely never again forget to put quotes around our attribute values.

Empty Tags: <hr> , <br> and <img>
Empty tags are not allowed in XHTML. The <hr> and <br> tags should be replaced with <hr /> and <br />.

This produced a problem with Netscape that misinterpreted the <br/> tag. We don't know why, but changing it to <br /> worked fine. After that discovery, a general search and replace function was executed to swap the tags.

A few other tags (like the <img> tag) were suffering from the same problem as above. We decided not to close the <img> tags with </img>, but with /> at the end of the tag. This was done manually.

The Web Site Was Validated
After that, all pages were validated against the official W3C DTD with this link: XHTML Validator. A few more errors were found and edited manually. The most common error was missing </li> tags in lists.

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