Doxygen and localization

Are you localizing any documentation projects that use Doxygen? It's an open-source tool for documenting source code.

If your documentation set includes things like an API reference or extensive details in programming code, Doxygen allows you to embed tags in the original code or header files, then automatically create entire help systems organized around the tagged text. Doxygen does not compile anything, but takes the tagged bits of source files, turns them into HTML pages, then links them for viewing in a browser.

Like most tools, it's a breath of fresh air when it works properly, but it can require a lot of re-plumbing and retrofitting.

As far as localization goes, it can be a life-saver. In theory, you can have the header files themselves localized, then run them through Doxygen as you would the original English files. Working this far upstream can be a big advantage.

Some months ago a client embarked on a conversion of a help system to Doxygen. While it was still in the proof-of-concept stage, we pseudo-translated some header files and tested the tool for global-readiness.

The good news is that the developers of Doxygen have enabled it for multiple languages. It encodes pages in UTF-8 (or other character sets), so translated text displays properly in the browser. It's possible to set the OUTPUT_LANGUAGE parameter to your target language (e.g., Japanese, in our test scenario) so that the datestamp and other text supplied by Doxygen displays in Japanese, rather than in the default English.

There are some I18n problems with Doxygen, though.

• Each header file page begins with "Collaboration diagram for" followed by the page title. When the page title contains double-byte characters, the Japanese characters for "Collaboration diagram for" are corrupted. It appears that Doxygen is not pushing UTF-8 characters for this phrase, though it pushes UTF-8 characters in other places.
• Some hyperlinked words in body text will require translation. If so, it will be important to ensure that they are translated the same everywhere. Note, however, that Doxygen will not generate the necessary file if the hyperlink has double-byte characters in it (not even on a Japanese OS).
• Doxygen allows for generation of the .hhc, .hhp and .hhk files needed for Compiled HTML Help (CHM). It can also be configured to execute hhc.exe and compile the project. However, Doxygen outputs the .hhc file in UTF-8 format, which is incompatible with the table of contents pane in the Help viewer. To fix this, open the .hhc in Notepad (preferably on a Japanese OS) and save it back out as Shift-JIS ("ANSI" in Japanese Notepad). Then recompile the CHM by invoking hhc.exe from the command line and the contents will show up properly.
• Searches using single- or double-byte characters do not work in the resulting CHM.

These strike me as rather large, empty boxes on the checklist of global-readiness. Still, the source code is available, so if your organization has already started down the Doxygen path, you can clean up problems like these for your worldwide versions.

Interested in this topic? You might enjoy another article I've written called Localizing Robohelp Projects.