How to include the source line number everywhere in html output in Sphinx? - python-sphinx

Question

Let's say I'm writing a custom editor for my RestructuredText/Sphinx stuff, with "live" html output preview. Output is built using Sphinx.
The source files are pure RestructuredText. No code there.
One desirable feature would be that right-clicking on some part of the preview opens the editor at the correct line of the source file.
To achieve that, one way would be to put that line number in every tag of the html file, for example using classes (e.g., class = "... lineno-124"). Or use html comments.
Note that I don't want to add more content to my source files, just that the line number be included everywhere in the output.
An approximate line number would be enough.
Someone knows how to do this in Sphinx, my way or another?

Answer 1

I decided to add <a> tags with a specific class "lineno lineno-nnn" where nnn is the line number in the RestructuredText source.
The directive .. linenocomment:: nnn is inserted before each new block of unindented text in the source, before the actual parsing (using a 'source-read' event hook).
linenocomment is a custom directive that pushes the <a> tag at build time.
Half a solution is still a solution...
import docutils.nodes as dn
from docutils.parsers.rst import Directive
class linenocomment(dn.General,dn.Element):
pass
def visit_linenocomment_html(self,node):
self.body.append(self.starttag(node,'a',CLASS="lineno lineno-{}".format(node['lineno'])))
def depart_linenocomment_html(self,node):
self.body.append('</a>')
class LineNoComment(Directive):
required_arguments = 1
optional_arguments = 0
has_content = False
add_index = False
def run(self):
node = linenocomment()
node['lineno'] = self.arguments[0]
return [node]
def insert_line_comments(app, docname, source):
print(source)
new_source = []
last_line_empty = True
lineno = 0
for line in source[0].split('\n'):
if line.strip() == '':
last_line_empty = True
new_source.append(line)
elif line[0].isspace():
new_source.append(line)
last_line_empty = False
elif not last_line_empty:
new_source.append(line)
else:
last_line_empty = False
new_source.append('.. linenocomment:: {}'.format(lineno))
new_source.append('')
new_source.append(line)
lineno += 1
source[0] = '\n'.join(new_source)
print(source)
def setup(app):
app.add_node(linenocomment,html=(visit_linenocomment_html,depart_linenocomment_html))
app.add_directive('linenocomment', LineNoComment)
app.connect('source-read',insert_line_comments)
return {
'version': 0.1
}