Add support for any language:

codeinclude/languages.py

@@ -0,0 +1,20 @@
+from pygments.lexers import get_lexer_for_filename
+from pygments.util import ClassNotFound
+
+
+def get_lang_class(filename: str) -> str:
+    """Returns the Pygments _language alias_ for the filename.
+
+    Pygments is used by codehilite, a widely used extension for code highlighting:
+    https://squidfunk.github.io/mkdocs-material/extensions/codehilite/
+
+    The Pygments language aliases are expected to be compatible with highlight.js language classes,
+    which are used by some MkDocs themes: https://www.mkdocs.org/user-guide/styling-your-docs/#built-in-themes
+    For a table of 'Language -> Language Classes' in _highlight.js_,
+    see https://github.com/highlightjs/highlight.js#supported-languages
+    """
+    try:
+        lexer = get_lexer_for_filename(filename)
+        return lexer.aliases[0]
+    except ClassNotFound:
+        return "none"

codeinclude/plugin.py

@@ -5,6 +5,7 @@
 
 from mkdocs.plugins import BasePlugin
 from codeinclude.resolver import select
+from codeinclude.languages import get_lang_class
 
 RE_START = r"""(?x)
     ^
@@ -44,8 +45,13 @@ def get_substitute(page, title, filename, lines, block, inside_block):
     )
 
     dedented = textwrap.dedent(selected_content)
+    lang_code = get_lang_class(filename)
+    return f'''
+```{lang_code} tab="{title}"
+{dedented}
+```
 
-    return '\n```java tab="' + title + '"\n' + dedented + "\n```\n\n"
+'''
 
 
 class CodeIncludePlugin(BasePlugin):

setup.py

@@ -27,7 +27,7 @@ def read_file(fname):
     python_requires='>=3.6',
     install_requires=[
         'mkdocs>=0.17',
-        'mkdocs'
+        'pygments'
     ],
     classifiers=[
         'Development Status :: 5 - Production/Stable',

tests/codeinclude/test_languages.py

@@ -0,0 +1,18 @@
+import unittest
+from codeinclude.languages import get_lang_class
+
+
+class MyTestCase(unittest.TestCase):
+    def test_get_lang_class(self):
+        self.assertEquals('java', get_lang_class('HelloWorld.java'))
+        self.assertEquals('python', get_lang_class('HelloWorld.py'))
+        self.assertEquals('csharp', get_lang_class('HelloWorld.cs'))
+        self.assertEquals('rust', get_lang_class('HelloWorld.rs'))
+        self.assertEquals('docker', get_lang_class('Dockerfile'))
+        self.assertEquals('xml', get_lang_class('HelloWorld.xml'))
+        self.assertEquals('toml', get_lang_class('HelloWorld.toml'))
+        self.assertEquals('json', get_lang_class('HelloWorld.json'))
+
+
+if __name__ == '__main__':
+    unittest.main()