Source code for swh.web.utils.highlightjs

# Copyright (C) 2017-2022  The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU Affero General Public License version 3, or any later version
# See top-level LICENSE file for more information

import functools
import json
from typing import Dict

from pygments.lexers import get_all_lexers, get_lexer_for_filename
from pygments.util import ClassNotFound

from django.contrib.staticfiles.finders import find

def _hljs_languages_data():
    with open(str(find("json/highlightjs-languages.json")), "r") as hljs_languages_file:
        return json.load(hljs_languages_file)

# set of languages ids that can be highlighted by highlight.js library
def _hljs_languages():
    return set(_hljs_languages_data()["languages"])

# languages aliases defined in highlight.js
def _hljs_languages_aliases():
    language_aliases = _hljs_languages_data()["languages_aliases"]
    language_aliases.pop("robots.txt", None)
    return {
        "ml": "ocaml",
        "bsl": "1c",
        "ep": "mojolicious",
        "lc": "livecode",
        "p": "parser3",
        "pde": "processing",
        "rsc": "routeros",
        "s": "armasm",
        "sl": "rsl",
        "4dm": "4d",
        "kaos": "chaos",
        "dfy": "dafny",
        "ejs": "eta",
        "nev": "never",
        "m": "octave",
        "shader": "hlsl",
        "fx": "hlsl",
        "prg": "xsharp",
        "xs": "xsharp",
        "scd": "sclang",
        "c3t": "c3",
        "cbl": "cobol",
        "lkml": "lookml",
        "sdm": "sdml",

# dictionary mapping pygment lexers to hljs languages
_pygments_lexer_to_hljs_language: Dict[str, str] = {}

# dictionary mapping mime types to hljs languages
_mime_type_to_hljs_language = {
    "text/x-c": "c",
    "text/x-c++": "cpp",
    "text/x-msdos-batch": "dos",
    "text/x-lisp": "lisp",
    "text/x-shellscript": "bash",

# dictionary mapping filenames to hljs languages
_filename_to_hljs_language = {
    "cmakelists.txt": "cmake",
    ".htaccess": "apache",
    "httpd.conf": "apache",
    "access.log": "accesslog",
    "nginx.log": "accesslog",
    "resolv.conf": "dns",
    "dockerfile": "docker",
    "nginx.conf": "nginx",
    "pf.conf": "pf",
    "robots.txt": "robots-txt",

# function to fill the above dictionaries
def _init_pygments_to_hljs_map():
    if len(_pygments_lexer_to_hljs_language) == 0:
        hljs_languages = _hljs_languages()
        hljs_languages_aliases = _hljs_languages_aliases()
        for lexer in get_all_lexers():
            lexer_name = lexer[0]
            lang_aliases = lexer[1]
            lang_mime_types = lexer[3]
            lang = None
            for lang_alias in lang_aliases:
                if lang_alias in hljs_languages:
                    lang = lang_alias
                    _pygments_lexer_to_hljs_language[lexer_name] = lang_alias
                if lang_alias in hljs_languages_aliases:
                    lang = hljs_languages_aliases[lang_alias]
                    _pygments_lexer_to_hljs_language[lexer_name] = lang_alias

            if lang:
                for lang_mime_type in lang_mime_types:
                    if lang_mime_type not in _mime_type_to_hljs_language:
                        _mime_type_to_hljs_language[lang_mime_type] = lang

[docs] def get_hljs_language_from_filename(filename): """Function that tries to associate a language supported by highlight.js from a filename. Args: filename: input filename Returns: highlight.js language id or None if no correspondence has been found """ _init_pygments_to_hljs_map() if filename: filename_lower = filename.lower() if filename_lower in _filename_to_hljs_language: return _filename_to_hljs_language[filename_lower] if filename_lower in _hljs_languages(): return filename_lower exts = filename_lower.split(".") # check if file extension matches an hljs language # also handle cases for ext in reversed(exts[-2:]): if ext in _hljs_languages(): return ext if ext in _hljs_languages_aliases(): return _hljs_languages_aliases()[ext] # otherwise use Pygments language database lexer = None # try to find a Pygment lexer try: lexer = get_lexer_for_filename(filename) except ClassNotFound: pass # if there is a correspondence between the lexer and an hljs # language, return it if lexer and in _pygments_lexer_to_hljs_language: return _pygments_lexer_to_hljs_language[] # otherwise, try to find a match between the file extensions # associated to the lexer and the hljs language aliases if lexer: exts = [ext.replace("*.", "") for ext in lexer.filenames] for ext in exts: if ext in _hljs_languages_aliases(): return _hljs_languages_aliases()[ext] return None
[docs] def get_hljs_language_from_mime_type(mime_type): """Function that tries to associate a language supported by highlight.js from a mime type. Args: mime_type: input mime type Returns: highlight.js language id or None if no correspondence has been found """ _init_pygments_to_hljs_map() if mime_type and mime_type in _mime_type_to_hljs_language: return _mime_type_to_hljs_language[mime_type] return None
[docs] @functools.lru_cache() def get_supported_languages(): """ Return the list of programming languages that can be highlighted using the highlight.js library. Returns: List[str]: the list of supported languages """ return sorted(list(_hljs_languages()))