Register component suites by importing.

.pylintrc

@@ -57,7 +57,8 @@ confidence=
 disable=fixme,
         missing-docstring,
         invalid-name,
-        too-many-lines
+        too-many-lines,
+        old-style-class
 # Enable the message, report, category or checker with the given id(s). You can
 # either give multiple identifier separated by comma (,) or put this option
 # multiple time (only on the command line, not in the configuration file where

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.29.0 - 2018-11-06
+## Added
+- Added component namespaces registry, collect the resources needed by component library when they are imported instead of crawling the layout. [#444](https://github.com/plotly/dash/pull/444)
+
 ## 0.28.7 - 2018-11-05
 ## Fixed
 - Component generation now uses the same prop name black list in all supported Python versions. Closes [#361](https://github.com/plotly/dash/issues/361). [#450](https://github.com/plotly/dash/pull/450)

dash/development/base_component.py

@@ -2,9 +2,53 @@
 import copy
 import os
 import inspect
+import abc
+import sys
+import six
+
 from ._all_keywords import kwlist
 
 
+# pylint: disable=no-init,too-few-public-methods
+class ComponentRegistry:
+    """Holds a registry of the namespaces used by components."""
+
+    registry = set()
+    __dist_cache = {}
+
+    @classmethod
+    def get_resources(cls, resource_name):
+        cached = cls.__dist_cache.get(resource_name)
+
+        if cached:
+            return cached
+
+        cls.__dist_cache[resource_name] = resources = []
+
+        for module_name in cls.registry:
+            module = sys.modules[module_name]
+            resources.extend(getattr(module, resource_name, []))
+
+        return resources
+
+
+class ComponentMeta(abc.ABCMeta):
+
+    # pylint: disable=arguments-differ
+    def __new__(mcs, name, bases, attributes):
+        component = abc.ABCMeta.__new__(mcs, name, bases, attributes)
+        module = attributes['__module__'].split('.')[0]
+        if name == 'Component' or module == 'builtins':
+            # Don't do the base component
+            # and the components loaded dynamically by load_component
+            # as it doesn't have the namespace.
+            return component
+
+        ComponentRegistry.registry.add(module)
+
+        return component
+
+
 def is_number(s):
     try:
         float(s)
@@ -53,6 +97,7 @@ def wrapper(*args, **kwargs):
     return wrapper
 
 
+@six.add_metaclass(ComponentMeta)
 class Component(collections.MutableMapping):
     class _UNDEFINED(object):
         def __repr__(self):

dash/development/component_loader.py

@@ -3,6 +3,7 @@
 import os
 from .base_component import generate_class
 from .base_component import generate_class_file
+from .base_component import ComponentRegistry
 
 
 def _get_metadata(metadata_path):
@@ -30,6 +31,8 @@ def load_components(metadata_path,
     `type`, `valid_kwargs`, and `setup`.
     """
 
+    # Register the component lib for index include.
+    ComponentRegistry.registry.add(namespace)
     components = []
 
     data = _get_metadata(metadata_path)

dash/resources.py

@@ -1,9 +1,8 @@
-from copy import copy
 import json
 import warnings
 import os
 
-from .development.base_component import Component
+from .development.base_component import ComponentRegistry
 
 
 # pylint: disable=old-style-class
@@ -12,6 +11,7 @@ def __init__(self, resource_name, layout):
         self._resources = []
         self.resource_name = resource_name
         self.layout = layout
+        self._resources_cache = []
 
     def append_resource(self, resource):
         self._resources.append(resource)
@@ -59,45 +59,18 @@ def _filter_resources(self, all_resources, dev_bundles=False):
         return filtered_resources
 
     def get_all_resources(self, dev_bundles=False):
-        all_resources = []
-        if self.config.infer_from_layout:
-            all_resources = (
-                self.get_inferred_resources() + self._resources
-            )
-        else:
-            all_resources = self._resources
+        if self._resources_cache:
+            return self._resources_cache
 
-        return self._filter_resources(all_resources, dev_bundles)
+        all_resources = ComponentRegistry.get_resources(self.resource_name)
+        all_resources.extend(self._resources)
 
-    def get_inferred_resources(self):
-        namespaces = []
-        resources = []
-        layout = self.layout
+        self._resources_cache = res = \
+            self._filter_resources(all_resources, dev_bundles)
+        return res
 
-        def extract_resource_from_component(component):
-            # pylint: disable=protected-access
-            if (isinstance(component, Component) and
-                    component._namespace not in namespaces):
 
-                namespaces.append(component._namespace)
-
-                if hasattr(component, self.resource_name):
-
-                    component_resources = copy(
-                        getattr(component, self.resource_name)
-                    )
-                    for r in component_resources:
-                        r['namespace'] = component._namespace
-                    resources.extend(component_resources)
-
-        extract_resource_from_component(layout)
-        for t in layout.traverse():
-            extract_resource_from_component(t)
-        return resources
-
-
-class Css:
-    # pylint: disable=old-style-class
+class Css:  # pylint: disable=old-style-class
     def __init__(self, layout=None):
         self._resources = Resources('_css_dist', layout)
         self._resources.config = self.config
@@ -111,9 +84,6 @@ def append_css(self, stylesheet):
     def get_all_css(self):
         return self._resources.get_all_resources()
 
-    def get_inferred_css_dist(self):
-        return self._resources.get_inferred_resources()
-
     # pylint: disable=old-style-class, no-init, too-few-public-methods
     class config:
         infer_from_layout = True
@@ -134,9 +104,6 @@ def append_script(self, script):
     def get_all_scripts(self, dev_bundles=False):
         return self._resources.get_all_resources(dev_bundles)
 
-    def get_inferred_scripts(self):
-        return self._resources.get_inferred_resources()
-
     # pylint: disable=old-style-class, no-init, too-few-public-methods
     class config:
         infer_from_layout = True

dash/version.py

@@ -1 +1 @@
-__version__ = '0.28.7'
+__version__ = '0.29.0'

tests/test_integration.py

@@ -531,3 +531,27 @@ def create_layout():
 
         self.startServer(app)
         time.sleep(0.5)
+
+    def test_late_component_register(self):
+        app = dash.Dash()
+
+        app.layout = html.Div([
+            html.Button('Click me to put a dcc ', id='btn-insert'),
+            html.Div(id='output')
+        ])
+
+        @app.callback(Output('output', 'children'),
+                      [Input('btn-insert', 'n_clicks')])
+        def update_output(value):
+            if value is None:
+                raise PreventUpdate
+
+            return dcc.Input(id='inserted-input')
+
+        self.startServer(app)
+
+        btn = self.wait_for_element_by_css_selector('#btn-insert')
+        btn.click()
+        time.sleep(1)
+
+        self.wait_for_element_by_css_selector('#inserted-input')