[pbs-devel] [PATCH proxmox-backup] docs: add prototype sphinx extension for online help

[Oguz Bektas]

goes through the sections in the documents and creates the
OnlineHelpInfo.js file from the explicitly defined section labels.

run "make scanrefs" in the docs folder to generate the output.

for example:

const pveOnlineHelpInfo = {
  "create-backups": {
    "link": "/docs/administration-guide.html#create-backups",
    "title": "Creating Backups"
  },
  "pruning": {
    "link": "/docs/administration-guide.html#pruning",
    "title": "Pruning and Removing Backups"
  },
  "id1": {
    "link": "/docs/administration-guide.html#id1",
    "title": "Garbage Collection"
  },
  "pve-integration": {
    "link": "/docs/administration-guide.html#pve-integration",
    "title": "`Proxmox VE`_ integration"
  },
  "pxar-format": {
    "link": "/docs/file-formats.html#pxar-format",
    "title": "Proxmox File Archive Format (``.pxar``)"
  },
  "sysadmin-package-repositories": {
    "link": "/docs/package-repositories.html#sysadmin-package-repositories",
    "title": "Debian Package Repositories"
  },
  "fake-label": {
    "link": "/docs/sysadmin.html#fake-label",
    "title": "Hardware"
  }
};

---
 docs/Makefile                 |  4 ++
 docs/_ext/proxmox-scanrefs.py | 90 +++++++++++++++++++++++++++++++++++
 docs/conf.py                  |  7 ++-
 3 files changed, 99 insertions(+), 2 deletions(-)
 create mode 100644 docs/_ext/proxmox-scanrefs.py

diff --git a/docs/Makefile b/docs/Makefile
index 34ec8809..796861b1 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -68,6 +68,10 @@ proxmox-backup-manager.1: proxmox-backup-manager/man1.rst  proxmox-backup-manage
 proxmox-backup-proxy.1: proxmox-backup-proxy/man1.rst  proxmox-backup-proxy/description.rst
 	rst2man $< >$@
 
+.PHONY: scanrefs
+scanrefs:
+	$(SPHINXBUILD) -b proxmox-scanrefs $(ALLSPHINXOPTS) $(BUILDDIR)/scanrefs
+
 .PHONY: html
 html: ${GENERATED_SYNOPSIS}
 	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
diff --git a/docs/_ext/proxmox-scanrefs.py b/docs/_ext/proxmox-scanrefs.py
new file mode 100644
index 00000000..bb0c532d
--- /dev/null
+++ b/docs/_ext/proxmox-scanrefs.py
@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+
+# debugging stuff
+from pprint import pprint
+
+from typing import cast
+
+import json
+import re
+
+import os
+import io
+from docutils import nodes
+
+from sphinx.builders import Builder
+from sphinx.util import logging
+
+logger = logging.getLogger(__name__)
+
+# refs are added in the following manner before the title of a section (note underscore and newline before title):
+# .. _my-label:
+#
+# Section to ref
+# --------------
+#
+#
+# then referred to like (note missing underscore):
+# "see :ref:`my-label`"
+#
+# the benefit of using this is if a label is explicitly set for a section,
+# we can refer to it with this anchor even if the section name changes.
+#
+# see https://www.sphinx-doc.org/en/master/usage/restructuredtext/roles.html#role-ref
+
+def setup(app):
+    logger.info('Mapping reference labels...')
+    app.add_builder(ReflabelMapper)
+    return {
+        'version': '0.1',
+        'parallel_read_safe': True,
+        'parallel_write_safe': True,
+    }
+
+class ReflabelMapper(Builder):
+    name = 'proxmox-scanrefs'
+
+    def init(self):
+        self.docnames = []
+        self.env.online_help = {}
+
+        if not os.path.isdir(self.outdir):
+            os.mkdir(self.outdir)
+
+        self.output_filename = os.path.join(self.outdir, 'OnlineHelpInfo.js')
+        self.output = io.open(self.output_filename, 'w', encoding='UTF-8')
+
+    def write_doc(self, docname, doctree):
+            for node in doctree.traverse(nodes.section):
+                #pprint(vars(node))
+
+                if hasattr(node, 'expect_referenced_by_id') and len(node['ids']) > 1: # explicit labels
+                    filename = self.env.doc2path(docname)
+                    filename_html = re.sub('.rst', '.html', filename)
+                    labelid = node['ids'][1] # [0] is predefined by sphinx, we need [1] for explicit ones
+                    title = cast(nodes.title, node[0])
+                    logger.info(f'traversing section {title.astext()}')
+                    ref_name = getattr(title, 'rawsource', title.astext())
+
+                    self.env.online_help[labelid]: dict = {'link': '', 'title': ''}
+                    self.env.online_help[labelid]['link'] = "/docs/" + os.path.basename(filename_html) + f"#{labelid}"
+                    self.env.online_help[labelid]['title'] = ref_name
+
+            return
+
+    def get_outdated_docs(self):
+        return 'all documents'
+
+    def prepare_writing(self, docnames):
+        return
+
+    def get_target_uri(self, docname, typ=None):
+        return ''
+
+    def finish(self):
+        # generate OnlineHelpInfo.js output
+        self.output.write("const pveOnlineHelpInfo = ")
+        self.output.write(json.dumps(self.env.online_help, indent=2))
+        self.output.write(";\n")
+        self.output.close()
+        return
diff --git a/docs/conf.py b/docs/conf.py
index 0c40ffb5..a9d45c2e 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -18,9 +18,12 @@
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 #
 import os
-# import sys
+import sys
 # sys.path.insert(0, os.path.abspath('.'))
 
+# custom extensions
+sys.path.append(os.path.abspath("./_ext"))
+
 # -- Implement custom formatter for code-blocks ---------------------------
 #
 # * use smaller font
@@ -46,7 +49,7 @@ PygmentsBridge.latex_formatter = CustomLatexFormatter
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 
-extensions = ["sphinx.ext.graphviz", "sphinx.ext.todo"]
+extensions = ["sphinx.ext.graphviz", "sphinx.ext.todo", "proxmox-scanrefs"]
 
 todo_link_only = True
 
-- 
2.20.1