Mount sub-applications

src/microdot.py

@@ -543,6 +543,7 @@ class Response():
 
 class URLPattern():
     def __init__(self, url_pattern):
+        self.url_pattern = url_pattern
         self.pattern = ''
         self.args = []
         use_regex = False
@@ -798,6 +799,23 @@ class Microdot():
             return f
         return decorated
 
+    def mount(self, subapp, url_prefix=''):
+        """Mount a sub-application, optionally under the given URL prefix.
+
+        :param subapp: The sub-application to mount.
+        :param url_prefix: The URL prefix to mount the application under.
+        """
+        for methods, pattern, handler in subapp.url_map:
+            self.url_map.append(
+                (methods, URLPattern(url_prefix + pattern.url_pattern),
+                 handler))
+        for handler in subapp.before_request_handlers:
+            self.before_request_handlers.append(handler)
+        for handler in subapp.after_request_handlers:
+            self.after_request_handlers.append(handler)
+        for status_code, handler in subapp.error_handlers.items():
+            self.error_handlers[status_code] = handler
+
     def run(self, host='0.0.0.0', port=5000, debug=False):
         """Start the web server. This function does not normally return, as
         the server enters an endless listening loop. The :func:`shutdown`

tests/microdot/test_microdot.py

@@ -309,3 +309,41 @@ class TestMicrodot(unittest.TestCase):
         self.assertTrue(fd.response.startswith(b'HTTP/1.0 200 OK\r\n'))
         self.assertIn(b'Content-Type: text/plain\r\n', fd.response)
         self.assertTrue(fd.response.endswith(b'\r\n\r\nfoobar'))
+
+    def test_mount(self):
+        subapp = Microdot()
+
+        @subapp.before_request
+        def before(req):
+            req.g.before = 'before'
+
+        @subapp.after_request
+        def after(req, res):
+            return res.body + b':after'
+
+        @subapp.errorhandler(404)
+        def not_found(req):
+            return '404', 404
+
+        @subapp.route('/app')
+        def index(req):
+            return req.g.before + ':foo'
+
+        app = Microdot()
+        app.mount(subapp, url_prefix='/sub')
+
+        mock_socket.clear_requests()
+        fd = mock_socket.add_request('GET', '/app')
+        self._add_shutdown(app)
+        app.run()
+        self.assertTrue(fd.response.startswith(b'HTTP/1.0 404 N/A\r\n'))
+        self.assertIn(b'Content-Type: text/plain\r\n', fd.response)
+        self.assertTrue(fd.response.endswith(b'\r\n\r\n404'))
+
+        mock_socket.clear_requests()
+        fd = mock_socket.add_request('GET', '/sub/app')
+        self._add_shutdown(app)
+        app.run()
+        self.assertTrue(fd.response.startswith(b'HTTP/1.0 200 OK\r\n'))
+        self.assertIn(b'Content-Type: text/plain\r\n', fd.response)
+        self.assertTrue(fd.response.endswith(b'\r\n\r\nbefore:foo:after'))