The position of the tree unit element being formatted in its file or the total number of elements output to a file is interesting, for instance to format end of files, decide which navigation header or footer is needed and whether a rule should be output.
To get information on tree elements unit counter in files, use
count_elements_in_filename:
$count = $converter->count_elements_in_filename ($specification, $file_name) ¶Return tree unit element counter for $file_name, or undef if
the counter does not exist. The counter returned depends on $specification:
Return the number of unit elements associated with $file_name having already been processed.
Return the number of unit elements associated with $file_name that remains to be processed.
Return the total number of element units associated with the file.