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Symbolic References Between Living Documents

 
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The method of the previous section to generated symbolic hyperized links can easily be extended to external documents processed by LaTeX2HTML. When LaTeX2HTML processes a document, it generates a perl file named labels.pl   which contains a list of all the symbolic labels that were defined, along with their locations. The name of this file is preceeded by the , to allow different document segments to share the same directory. Links to an external document are then possible once a connection is established to that document's labels.pl file. This connection is established by the \externallabels command:   


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\externallabels{<URL to directory of external document>}
               {<external document labels.pl file>}

The first argument to externallabels should be a URL to the directory containing the external document. The second argument should be the full pathname to the labels.pl file belonging to the external document. Note that for remote external documents it is necessary to copy the labels.pl file locally so that it can be read when processing a local document that uses it. The command externallabels can be used once for each external document in order to import the external labels   into the current document. A warning is given if labels.pl cannot be found.


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If a symbolic reference made in either of the commands described in Section 3.4 is not defined within the document itself, LaTeX2HTML will look for that reference in one of the external files.gif After any modifications in an external document (sections added/deleted, segmentation into different physical parts, etc.) a new labels.pl will be generated. If the externallabels command in another document contains the correct address to the labels.pl file, then the cross-references will be realigned after running the local document through the translator.

There is also a mechanism analogous to the label-ref pairs of LaTeX, which can be used only within a single document. These labels are called internal labels  , as opposed to the external labels defined above.

Either type of label is defined with a LaTeX label command. Labels can be referenced within a document using a ref command. When processed by LaTeX, each ref command is replaced by the section number in which the corresponding label occurred. When processed by the translator, each ref is replaced by a hypertext link to the place where the corresponding label occurred. This mechanism can be extended to external documents by the \externalref{} command:

\externalref{<symbolic label in remote document>}

The argument to externalref may be any symbolic label defined in any of the external documents in the same Such references to external symbolic labels are then translated into hyperlinks pointing to the external document.


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next up previous contents index
Next: A Cross-referencing example Up: Hypertext Extensions to LaTeX Previous: Symbolic References Shown as

Bo Milvang-Jensen
Tue May 28 19:03:54 MET DST 1996