hgext/highlight.py

"""
This is Mercurial extension for syntax highlighting in the file
revision view of hgweb.

It depends on the pygments syntax highlighting library:
http://pygments.org/

To enable the extension add this to hgrc:

[extensions]
hgext.highlight =

There is a single configuration option:

[web]
pygments_style = <style>

The default is 'colorful'.  If this is changed the corresponding CSS
file should be re-generated by running

# pygmentize -f html -S <newstyle>


-- Adam Hupp <[e-mail]>


"""

from mercurial import demandimport
demandimport.ignore.extend(['pkgutil',
                            'pkg_resources',
                            '__main__',])

import mimetypes

from mercurial.hgweb import hgweb_mod
from mercurial.hgweb.hgweb_mod import hgweb
from mercurial import util
from mercurial.hgweb.common import paritygen
from mercurial.node import hex
from mercurial.templatefilters import filters

from pygments import highlight
from pygments.util import ClassNotFound
from pygments.lexers import guess_lexer_for_filename, TextLexer
from pygments.formatters import HtmlFormatter

SYNTAX_CSS = ('\n<link rel="stylesheet" href="#staticurl#highlight.css" '
              'type="text/css" />')

def pygmentize(self, tmpl, fctx, field):
    # append a <link ...> to the syntax highlighting css
    old_header = ''.join(tmpl('header'))
    if SYNTAX_CSS not in old_header:
        new_header =  old_header + SYNTAX_CSS
        tmpl.cache['header'] = new_header

    text = fctx.data()
    if util.binary(text):
        return

    style = self.config("web", "pygments_style", "colorful")
    # To get multi-line strings right, we can't format line-by-line
    try:
        lexer = guess_lexer_for_filename(fctx.path(), text,
                                         encoding=util._encoding)
    except ClassNotFound:
        lexer = TextLexer(encoding=util._encoding)

    formatter = HtmlFormatter(style=style, encoding=util._encoding)

    colorized = highlight(text, lexer, formatter)
    # strip wrapping div
    colorized = colorized[:colorized.find('\n</pre>')]
    colorized = colorized[colorized.find('<span'):]
    coloriter = (l for l in colorized.splitlines())

    filters['colorize'] = lambda x: coloriter.next()

    oldl = tmpl.cache[field]
    newl = oldl.replace('line|escape', 'line|colorize')
    tmpl.cache[field] = newl

def filerevision_highlight(self, tmpl, fctx):
    pygmentize(self, tmpl, fctx, 'fileline')

    return realrevision(self, tmpl, fctx)

def fileannotate_highlight(self, tmpl, fctx):
    pygmentize(self, tmpl, fctx, 'annotateline')

    return realannotate(self, tmpl, fctx)

# monkeypatch in the new version
# should be safer than overriding the method in a derived class
# and then patching the class
realrevision = hgweb.filerevision
hgweb.filerevision = filerevision_highlight
realannotate = hgweb.fileannotate
hgweb.fileannotate = fileannotate_highlight