Re: pdf page counting

On 12/24/2024 4:43 PM, Glen Walpert wrote:

I am fairly certain that what you want cannot be done with a PDF, based on
reading many documents where this would have been beneficial, such as the
3544 page Florida Building Code where the page labeled as (RAS)109.1 is
PDF page 2625, or the 1235 page Square-D Digest with page 22-1 on PDF page
968.  Both of these documents are made tolerable by links to major
sections from the index.  The Square-D Digest is exceptional in providing
hyperlinks to web documents with part specs, drawings and CAD files for
almost everything in the catalog.

PDFs deal with "pages" in three different contexts:
The file itself assumes the first page is '0' -- so, any
(PS) *code* that references a page begins counting from 0.
Of course, the code doesn't care what "human reference"
is visible on the page (which may actually be a COVER
that has NO page number!), nor should it.
Humans like to think of pages as starting with 1.  So,
absent any overriding information (see below), the N pages
in a PDF will be "numbered" 1 to N.
Because authors create documents with a variety of "page
numbering schemes", the PDF includes provisions for page
LABELS.  These can be damn near ANYTHING.  E.g., the
first page could be "greg", the second page "four", the
third page "XX", the fourth "¾", etc.  Typically, the
scheme chosen has an implied ordering so the user can predict
what the next such label will be, given the current one.
The authoring software is typically responsible for creating
user-friendly "page labels" for the document, based on settings
defined by the *author* at the time the document is created.
It can also place these labels ON the pages in the document
(as would be expected!).  E.g., my page 17 might actually appear
on the page as "II-03" if I adopt a <chapter>-<page-in-chapter>
presentation scheme (and chose uppercase roman numerals as chapter
numbers).  Or, it could be "Intro-3" if I chose to use chapter
names followed by page-within-chapter.
But, not all authoring tools are up to the task.  And, not
all *authors* are aware of these issues or the means of addressing
them.
And, of course, there is also a caveat for the range of possible
*readers* (viewers).  So, when picking an authoring tool, it's
important to consider which features you may want/need AND the
choice of reader/viewer that you will RECOMMEND your users
employ to read/view your documents.