Add triggered_id to callback_context

Author: AnnMarieW

dash/__init__.py

@@ -19,7 +19,7 @@
 from . import html  # noqa: F401,E402
 from . import dash_table  # noqa: F401,E402
 from .version import __version__  # noqa: F401,E402
-from ._callback_context import callback_context  # noqa: F401,E402
+from ._callback_context import callback_context, ctx  # noqa: F401,E402
 from ._callback import callback, clientside_callback  # noqa: F401,E402
 from ._get_paths import (  # noqa: F401,E402
     get_asset_url,

dash/_callback_context.py

@@ -1,6 +1,6 @@
 import functools
 import warnings
-
+import json
 import flask
 
 from . import exceptions
@@ -54,6 +54,18 @@ def triggered(self):
         # look empty, but you can still do `triggered[0]["prop_id"].split(".")`
         return getattr(flask.g, "triggered_inputs", []) or falsy_triggered
 
+    @property
+    @has_context
+    def triggered_ids(self):
+        triggered = getattr(flask.g, "triggered_inputs", [])
+        ids = {}
+        for item in triggered:
+            component_id, _, _ = item["prop_id"].rpartition(".")
+            ids[item["prop_id"]] = component_id
+            if component_id.startswith("{"):
+                ids[item["prop_id"]] = json.loads(component_id)
+        return ids
+
     @property
     @has_context
     def args_grouping(self):
@@ -145,3 +157,4 @@ def using_outputs_grouping(self):
 
 
 callback_context = CallbackContext()
+ctx = CallbackContext()

tests/integration/callbacks/test_callback_context.py

@@ -2,7 +2,7 @@
 import operator
 import pytest
 
-from dash import Dash, Input, Output, html, dcc, callback_context
+from dash import Dash, Input, Output, html, dcc, callback_context, ctx
 
 from dash.exceptions import PreventUpdate, MissingCallbackContextException
 import dash.testing.wait as wait
@@ -330,3 +330,28 @@ def update_results(n1, n2, nsum):
     assert len(keys1) == 2
     assert "sum-number.value" in keys1
     assert "input-number-2.value" in keys1
+
+
+def test_cbcx007_triggered_id(dash_duo):
+    app = Dash(__name__)
+
+    btns = ["btn-{}".format(x) for x in range(1, 6)]
+
+    app.layout = html.Div(
+        [html.Div([html.Button(btn, id=btn) for btn in btns]), html.Div(id="output")]
+    )
+
+    @app.callback(Output("output", "children"), [Input(x, "n_clicks") for x in btns])
+    def on_click(*args):
+        if not ctx.triggered:
+            raise PreventUpdate
+        for btn in btns:
+            if btn in ctx.triggered_ids.values():
+                return f"Just clicked {btn}"
+
+    dash_duo.start_server(app)
+
+    for i in range(1, 5):
+        for btn in btns:
+            dash_duo.find_element("#" + btn).click()
+            dash_duo.wait_for_text_to_equal("#output", f"Just clicked {btn}")