For example, Excel XHTML documents will have the following declaration:

This declares three separate namespaces, one each for generic Office names, Excel, and HTML. The last declaration's different in that there's no prefix. This indicates that all tags and parameters without a prefix are assumed to be plain HTML, making coding much simpler, and also allowing XHTML documents to pretend to be HTML documents.

These three namespaces could be used as below:

Note how the XML names closely match the existing COM document object models for Excel and Office. The tags don't, however, match those used in the preview of XML incorporated into Excel 97. For example, the FORMULA attribute (as used on the <TD> tag) is now known as X:FMLA, but used in the same fashion, as below:

Putting on the Style
When Office documents try to transfer the format of the original document to HTML, they use a mixture of CSS v1, CSS v2, and conditional HTML. This means that a browser that only supports CSS v1 will still be able to show some basic formatting, although not with the precision and variety that a CSS v2 capable browser will display. The conditional HTML involves commented IF and ENDIF statements that select HTML code for specific platforms, to work around the different ways various systems will treat the same HTML code.

While it's possible to create a single Web file containing the HTML, XML, and dataset and have it successfully open into Excel, there's a different method used by Excel when saving files. It'll generate a single master Web page, containing all the XML to describe the workbook. Then it'll separate files into a sub folder for each worksheet, a table of contents in XML called filelist.xml, formatting in stylesheet, CSS, and the workbook tabs in tabstrip.htm, plus images and macro files as required. The master file holds all of this together in two separate ways -- by building a frameset for display in a Web browser and by means of <LINK> tags for the benefit of Excel.

If interactivity has been selected in the file save box, the Web pages are built using the Office Web Components, with the XML for charts or worksheets created as escaped XML parameters for the objects. The code itself isn't included, being a sizable download, but the location of the components can be set as a parameter within the XML document properties. If you create your own Office Web pages from Domino, you have full control of where this location's set, as this example LotusScript code shows: