Intercept KeyError on navigation straight to the metadata tab without adding a config.

tests/test_integration/test_common_layout.py

@@ -34,16 +34,12 @@ def test_components_created(
 
     # wait for sidebar to be rendered
     try:
-        dash_duo.wait_for_text_to_equal(
-            "#sidebar h2", "WAZP 🐝", timeout=timeout
-        )
+        dash_duo.wait_for_text_to_equal("#sidebar h2", "WAZP 🐝", timeout=timeout)
     except selenium.common.exceptions.TimeoutException:
         pytest.fail("Sidebar component not generated")
 
     # check there are no errors in browser console
-    assert (
-        dash_duo.get_logs() == []
-    ), f"There are {len(dash_duo.get_logs())} errors"
+    assert dash_duo.get_logs() == [], f"There are {len(dash_duo.get_logs())} errors"
     " in the browser console!"
 
 
@@ -70,8 +66,8 @@ def test_components_created(
         pytest.param(fx, marks=mark)
         for fx, mark in [
             ("home_page_name_and_title", []),
-            ("metadata_page_name_and_title", unloaded_config_xfail),
-            ("roi_page_name_and_title", unloaded_config_xfail),
+            ("metadata_page_name_and_title", []),
+            ("roi_page_name_and_title", []),
             ("pose_estimation_page_name_and_title", []),
             ("dashboard_page_name_and_title", unloaded_config_xfail),
         ]
@@ -133,6 +129,4 @@ def test_sidebar_links(
     # ...
 
     # NOTE: this is expected to fail for a few pages (hence the marked xfails)
-    assert (
-        dash_duo.get_logs() == []
-    ), "There are errors in the browser console!"
+    assert dash_duo.get_logs() == [], "There are errors in the browser console!"

wazp/app.py

@@ -86,7 +86,7 @@
 storage = dcc.Store(
     id="session-storage",
     storage_type="session",
-    data=tuple(),
+    data={},
 )
 
 ###############

wazp/callbacks/_common.py

@@ -0,0 +1,8 @@
+from dash import html
+
+NO_CONFIG_MESSAGE = html.Div(
+    children="No configuration loaded. Please add a "
+    "configuration file from the 'Home' page."
+)
+
+VIDEO_TYPES = [".avi", ".mp4"]

wazp/callbacks/metadata.py

@@ -2,6 +2,8 @@
 import io
 import pathlib as pl
 import re
+import warnings
+from typing import Union
 
 import dash
 import dash_bootstrap_components as dbc
@@ -10,9 +12,7 @@
 from dash import Input, Output, State, dash_table, dcc, html
 
 from wazp import utils
-
-# TODO: other video extensions? have this in project config file instead?
-VIDEO_TYPES = [".avi", ".mp4"]
+from wazp.callbacks._common import NO_CONFIG_MESSAGE, VIDEO_TYPES
 
 
 ##########################
@@ -215,7 +215,7 @@ def get_callbacks(app: dash.Dash) -> None:
     )
     def create_metadata_table_and_buttons(
         metadata_output_children: list, app_storage: dict
-    ) -> html.Div:
+    ) -> Union[html.Div, None]:
         """Generate html component with a table holding the
         metadata per video and with auxiliary buttons for
         common table manipulations.
@@ -237,8 +237,20 @@ def create_metadata_table_and_buttons(
         html.Div
             html component holding the metadata dash_table and
             the auxiliary buttons for common table manipulations
+
+        Warns
+        -----
+        UserWarning
+            If no configuration is found (from navigating directly
+            to the ROI tab, for example).
         """
 
+        if not app_storage:
+            # we've likely navigated to the metadata page without an input
+            # config yaml file... not necessarily an error
+            warnings.warn("Configuration not yet loaded.")
+            return NO_CONFIG_MESSAGE
+
         if not metadata_output_children:
             metadata_table = create_metadata_table_component_from_df(
                 utils.df_from_metadata_yaml_files(
@@ -367,6 +379,7 @@ def create_metadata_table_and_buttons(
                     generate_yaml_tooltip,
                 ]
             )
+        return None
 
     @app.callback(
         Output("metadata-table", "data"),

wazp/callbacks/roi.py

@@ -13,9 +13,8 @@
 from PIL import Image
 
 from wazp import utils
+from wazp.callbacks._common import VIDEO_TYPES
 
-# TODO: other video extensions? have this in project config file instead?
-VIDEO_TYPES = [".avi", ".mp4"]
 ROI_CMAP = px.colors.qualitative.Dark24
 
 
@@ -521,6 +520,8 @@ def update_frame_graph(
         int
             Maximum frame index (num_frames - 1)
         """
+        if not roi_color_mapping:
+            return dash.no_update, "", "light", False
 
         # If a negative frame index is passed, it means that the video
         # could not be read correctly. So don't update the frame,