Links

Links are the essence of every hypertext document. Besides referencing related information, it can be (and is!) used to provide navigation inside a document in HTML. Therefore, it's important to make sure that every link is working properly, to ensure correct navigation, especially in the navigation bar, but also in the table of contents and the index. While HTML-browsers display in detail that a link is broken when followed, PDF readers will act as if the link wasn't there if the linked destination is not available.

Also to provide smooth navigation, the navigation bar should be visible when following a link to a new page. This is not the case when converting L^ATEX documents to HTML with latex2html, as the links produced by that tool rather address the first heading on a page, resulting in the navigation bar being scrolled out. When the user of the document decides he wants to go to the next page immediately, he has to use the scoll bar first, which is bad. Rather, these links of the form ``xxx#yyy'' need to be converted into simple links of the form ``xxx'', so the navigation bar's also visible.

As far as possible and supported by source format and converter tools, cross references inside a document should be converted into links as well as any available index.

For links of the form ``see chapter XXX'', ``see section XXX'', ``see figure XXX'', the chapter-, section- or figure-number ``XXX'' can be the anchor of the link, pointing at the referenced object. For references naming a page (``see page XXX''), it is hardly possible to name a page numer at all, and even in those cases it's unlikely that the named location has anything to do with a physical page. Therefore, it's ok to use some sort of button as an anchor for the link, instead of the page number, as shown in Figure 15.

  

Figure 15: Page references with images as anchor

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When using the icon provided by latex2html and choosing a non-standard background color, the icon must be fixed so only the edges are transparent, not the center.

In the index, there's a greater variety on how to display a anchor. Possible solutions are a virtual page-number that's only there to provide an anchor, an image just as described above, or listing the referenced section's number and/or heading. Figures 16, 17, 18, 19 and 20 show some examples.

  

Figure 16: Virtual page numers as anchors for links in index.

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Figure 17: Section numbers as anchors for links in index.

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Figure 18: Section names as anchors for links in index.

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Figure 19: Section numbers and names as anchors for links in index.

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Figure 20: Keywords as anchors for links in index.

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When the \ref and \pageref are used in a L^ATEX document that is then converted to HTML using latex2html, a small square is placed as anchor, instead of any page/section number. To turn this into plain text, information written into the .aux file can be used to gain these page/section number. An example script for this can be found in the conversion report from Graf/Eibisch [5].