docbook: Factor out code to write valid DocBook IDs

Attributes in XML may contain alphanumeric characters, underscores,
colons and dots.  When DocBook is chunked, the dot is often used as a
path separator.  To generate a valid ID, we take the title of the
section, transform all non-alphanumeric characters to underscores and
then add a prefix separated with dots.  We also add the document name as
a prefix, in order to 'xinclude' eg. cmake.docbook and ctest.docbook in
the same document.  IDs are written in multiple places, so the code is
factored to a function.

1 files changed, 2 insertions, 0 deletions

diff --git a/Source/cmDocumentationFormatterDocbook.h b/Source/cmDocumentationFormatterDocbook.h
index 213948d..6c96900 100644
--- a/Source/cmDocumentationFormatterDocbook.h
+++ b/Source/cmDocumentationFormatterDocbook.h
@@ -35,7 +35,9 @@ public:
   virtual void PrintPreformatted(std::ostream& os, const char* text);
   virtual void PrintParagraph(std::ostream& os, const char* text);
 private:
+  void PrintId(std::ostream& os, const char* prefix, std::string id);
   std::set<std::string> EmittedLinkIds;
+  std::string docname;
 };
 
 #endif