New docs extras

CHANGELOG.md

@@ -5,7 +5,11 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 ## [UNRELEASED]
 
 ## Dash and Dash Renderer
+### Added
+- [#1675](https://github.com/plotly/dash/pull/1675) Add new `Dash` constructor argument `extra_hot_reload_paths`. This allows you to re-initialize the Python code of the app when non-Python files change, if you know that these files impact the app.
+
 ### Changed
+- [#1675](https://github.com/plotly/dash/pull/1675) Remove the constraint that `requests_pathname_prefix` ends with `routes_pathname_prefix`. When you are serving your app behind a reverse proxy that rewrites URLs that constraint needs to be violated.
 - [#1611](https://github.com/plotly/dash/pull/1611) Package dash-renderer artifacts and dependencies with Dash, and source renderer resources from within Dash.
 - [#1567](https://github.com/plotly/dash/pull/1567) Julia component generator puts components into `src/jl` - fixes an issue on case-insensitive filesystems when the component name and module name match (modulo case) and no prefix is used. Also reduces JS/Julia clutter in the overloaded `src` directory.
 

dash/_configs.py

@@ -117,9 +117,5 @@ def pathname_configs(
         raise exceptions.InvalidConfig(
             "`requests_pathname_prefix` needs to start with `/`"
         )
-    if not requests_pathname_prefix.endswith(routes_pathname_prefix):
-        raise exceptions.InvalidConfig(
-            "`requests_pathname_prefix` needs to ends with `routes_pathname_prefix`."
-        )
 
     return url_base_pathname, routes_pathname_prefix, requests_pathname_prefix

dash/dash.py

@@ -232,6 +232,11 @@ class Dash(object):
         and redo buttons for stepping through the history of the app state.
     :type show_undo_redo: boolean
 
+    :param extra_hot_reload_paths: A list of paths to watch for changes, in
+        addition to assets and known Python and JS code, if hot reloading is
+        enabled.
+    :type extra_hot_reload_paths: list of strings
+
     :param plugins: Extend Dash functionality by passing a list of objects
         with a ``plug`` method, taking a single argument: this app, which will
         be called after the Flask server is attached.
@@ -269,6 +274,7 @@ def __init__(
         suppress_callback_exceptions=None,
         prevent_initial_callbacks=False,
         show_undo_redo=False,
+        extra_hot_reload_paths=None,
         plugins=None,
         title="Dash",
         update_title="Updating...",
@@ -329,6 +335,7 @@ def __init__(
             ),
             prevent_initial_callbacks=prevent_initial_callbacks,
             show_undo_redo=show_undo_redo,
+            extra_hot_reload_paths=extra_hot_reload_paths or [],
             title=title,
             update_title=update_title,
         )
@@ -1730,4 +1737,14 @@ def verify_url_part(served_part, url_part, part_name):
 
             self.logger.info("Dash is running on %s://%s%s%s\n", *display_url)
 
+        if self.config.extra_hot_reload_paths:
+            extra_files = flask_run_options["extra_files"] = []
+            for path in self.config.extra_hot_reload_paths:
+                if os.path.isdir(path):
+                    for dirpath, _, filenames in os.walk(path):
+                        for fn in filenames:
+                            extra_files.append(os.path.join(dirpath, fn))
+                elif os.path.isfile(path):
+                    extra_files.append(path)
+
         self.server.run(host=host, port=port, debug=debug, **flask_run_options)

dash/development/component_generator.py

@@ -49,6 +49,7 @@ def generate_components(
     rimports="",
     rsuggests="",
     jlprefix=None,
+    metadata=None,
 ):
 
     project_shortname = project_shortname.replace("-", "_").rstrip("/\\")
@@ -61,36 +62,37 @@ def generate_components(
 
     os.environ["NODE_PATH"] = "node_modules"
 
-    cmd = shlex.split(
-        'node {} "{}" "{}" {}'.format(
-            extract_path, ignore, reserved_patterns, components_source
-        ),
-        posix=not is_windows,
-    )
-
     shutil.copyfile(
         "package.json", os.path.join(project_shortname, package_info_filename)
     )
 
-    proc = subprocess.Popen(
-        cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=is_windows
-    )
-    out, err = proc.communicate()
-    status = proc.poll()
-
-    if err:
-        print(err.decode(), file=sys.stderr)
-
-    if not out:
-        print(
-            "Error generating metadata in {} (status={})".format(
-                project_shortname, status
+    if not metadata:
+        cmd = shlex.split(
+            'node {} "{}" "{}" {}'.format(
+                extract_path, ignore, reserved_patterns, components_source
             ),
-            file=sys.stderr,
+            posix=not is_windows,
+        )
+
+        proc = subprocess.Popen(
+            cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=is_windows
         )
-        sys.exit(1)
+        out, err = proc.communicate()
+        status = proc.poll()
+
+        if err:
+            print(err.decode(), file=sys.stderr)
+
+        if not out:
+            print(
+                "Error generating metadata in {} (status={})".format(
+                    project_shortname, status
+                ),
+                file=sys.stderr,
+            )
+            sys.exit(1)
 
-    metadata = safe_json_loads(out.decode("utf-8"))
+        metadata = safe_json_loads(out.decode("utf-8"))
 
     generator_methods = [generate_class_file]
 
@@ -148,7 +150,7 @@ def safe_json_loads(s):
     return byteify(jsondata_unicode)
 
 
-def cli():
+def component_build_arg_parser():
     parser = argparse.ArgumentParser(
         prog="dash-generate-components",
         formatter_class=_CombinedFormatter,
@@ -199,8 +201,11 @@ def cli():
         help="Specify a prefix for Dash for R component names, write "
         "components to R dir, create R package.",
     )
+    return parser
+
 
-    args = parser.parse_args()
+def cli():
+    args = component_build_arg_parser().parse_args()
     generate_components(
         args.components_source,
         args.project_shortname,