Specifying anchor names in reST

Question

I'm creating HTML from reST using the rst2html tool which comes with docutils. It seems that the code already assigns id attributes to the individual sections, which can be used as fragment identifiers in a URL, i.e. as anchors to jump to a specific part of the page. Those id values are based on the text of the section headline. When I change the wording of that headline, the identifier will change as well, rendering old URLs invalid.

Is there a way to specify the name to use as an identifier for a given section, so that I can edit the headline without invalidating links? Would there be a way if I were to call the docutils publisher myself, from my own script?

Answer 1

I don't think you can set an explicit id in reST sections, but I could be mistaken.

If you'd rather have numbered ids, which will depend on the ordering of the sections in the document tree, rather than their titles, you can do it with a small change to document.set_id() method in docutils/nodes.py (at line 997 on my version.)

Here is the patch:

 def set_id(self, node, msgnode=None):
     for id in node['ids']:
         if id in self.ids and self.ids[id] is not node:
             msg = self.reporter.severe('Duplicate ID: "%s".' % id)
             if msgnode != None:
                 msgnode += msg
     if not node['ids']:
-        for name in node['names']:
-            id = self.settings.id_prefix + make_id(name)
-            if id and id not in self.ids:
-                break
-        else:
+        if True: #forcing numeric ids
             id = ''
             while not id or id in self.ids:
                 id = (self.settings.id_prefix +
                       self.settings.auto_id_prefix + str(self.id_start))
                 self.id_start += 1
         node['ids'].append(id)
     self.ids[id] = node
     return id

I just tested it and it generates the section ids as id1, id2...

If you don't want to change this system-wide file, you can probably monkey-patch it from a custom rst2html command.

Answer 2

I'm not sure if I really understand your question.

You can create explicit hyperlink targets to arbitrary locations in your document which can be used to reference these locations independent of the implicit hyperlink targets created by docutils:

.. _my_rstfile:

------------------
This is my rstfile
------------------

.. _a-section:

First Chapter
-------------

This a link to a-section_ which is located in my_rstfile_.

As it seems that you want to create links between multiple rst files I would however advise to use Sphinx as it can handle references to arbitrary locations between different files and has some more advantages, like a toctree and theming. You can use sphinx not only for source code documentation, but for general text processing. Something like an example is the Sphinx documentation itself (there are hundreds of other examples on readthedocs).

Invoking Sphinx should be simple using sphinx-quickstart. You can simply add your exiting rst-files to the toctree in index.rst and run make html. If you want to document python code you can use sphinx-apidoc which will automatically generate an API documentation.

Answer 3

I made a Sphinx extension to solve this problem. The extension takes the preceding internal target and uses that as the section's ID. Example (from bmu's answer):

.. _a-section:

First Chapter
-------------

The permalink on "First Chapter" would point to #a-section instead of #first-chapter. If there's multiple, it'll take the last one.

Link to the extension: https://github.com/GeeTransit/sphinx-better-subsection