From 6771920cb70ab38de269ed93553a976f600b55c2 Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Sun, 27 Feb 2022 17:31:58 -0700
Subject: [PATCH 01/13] Add triggered_id to callback_context

---
 dash/__init__.py                              |  2 +-
 dash/_callback_context.py                     | 15 ++++++++++-
 .../callbacks/test_callback_context.py        | 27 ++++++++++++++++++-
 3 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/dash/__init__.py b/dash/__init__.py
index 7e59891b8b..1b64bc170a 100644
--- a/dash/__init__.py
+++ b/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,
diff --git a/dash/_callback_context.py b/dash/_callback_context.py
index 585de7fc47..fdb21c38a4 100644
--- a/dash/_callback_context.py
+++ b/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()
diff --git a/tests/integration/callbacks/test_callback_context.py b/tests/integration/callbacks/test_callback_context.py
index e19c5e63ac..6f382a7a46 100644
--- a/tests/integration/callbacks/test_callback_context.py
+++ b/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}")

From 2728d83e2235e24aff497e271af3f992c843f62e Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Sun, 27 Feb 2022 18:12:20 -0700
Subject: [PATCH 02/13] added test

---
 .../callbacks/test_callback_context.py        | 28 ++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/tests/integration/callbacks/test_callback_context.py b/tests/integration/callbacks/test_callback_context.py
index 6f382a7a46..4ffaf6a278 100644
--- a/tests/integration/callbacks/test_callback_context.py
+++ b/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, ctx
+from dash import Dash, ALL, Input, Output, html, dcc, callback_context, ctx
 
 from dash.exceptions import PreventUpdate, MissingCallbackContextException
 import dash.testing.wait as wait
@@ -355,3 +355,29 @@ def on_click(*args):
         for btn in btns:
             dash_duo.find_element("#" + btn).click()
             dash_duo.wait_for_text_to_equal("#output", f"Just clicked {btn}")
+
+
+def test_cbcx008_triggered_id_pmc(dash_duo):
+
+    app = Dash()
+    app.layout = html.Div(
+        [
+            html.Button("Click me", id={"type": "btn", "index": "myindex"}),
+            html.Div(id="output"),
+        ]
+    )
+
+    @app.callback(
+        Output("output", "children"), Input({"type": "btn", "index": ALL}, "n_clicks")
+    )
+    def func(n_clicks):
+        if ctx.triggered:
+            triggered_id, dict_id = next(iter(ctx.triggered_ids.items()))
+            if dict_id == {"type": "btn", "index": "myindex"}:
+                return dict_id["index"]
+
+    dash_duo.start_server(app)
+    dash_duo.find_element(
+        '#\\{\\"index\\"\\:\\"myindex\\"\\,\\"type\\"\\:\\"btn\\"\\}'
+    ).click()
+    dash_duo.wait_for_text_to_equal("#output", "myindex")

From d19f04c9529d624a8d8f9d02f047c4e972f9d4db Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Thu, 3 Mar 2022 14:20:45 -0700
Subject: [PATCH 03/13] extended ctx.arg_grouping and changed it to
 AttributeDict

---
 dash/_callback_context.py | 54 ++++++++++++++++++++++++++++++++++++++-
 dash/_grouping.py         |  5 ++--
 dash/_utils.py            |  2 +-
 dash/_validate.py         |  5 ++++
 dash/dash.py              |  3 +++
 5 files changed, 65 insertions(+), 4 deletions(-)

diff --git a/dash/_callback_context.py b/dash/_callback_context.py
index fdb21c38a4..879bf209e0 100644
--- a/dash/_callback_context.py
+++ b/dash/_callback_context.py
@@ -1,6 +1,7 @@
 import functools
 import warnings
 import json
+from copy import deepcopy
 import flask
 
 from . import exceptions
@@ -69,7 +70,58 @@ def triggered_ids(self):
     @property
     @has_context
     def args_grouping(self):
-        return getattr(flask.g, "args_grouping", [])
+        triggered = getattr(flask.g, "triggered_inputs", [])
+        triggered = [item["prop_id"] for item in triggered]
+        grouping = getattr(flask.g, "args_grouping", {})
+
+        def update_args_grouping(g):
+            if isinstance(g, dict) and "id" in g:
+                prop_id = ".".join((g["id"], g["property"]))
+
+                new_values = {
+                    "value": g.get("value"),
+                    "id": g["id"]
+                    if not g["id"].startswith("{")
+                    else json.loads(g["id"]),
+                    "property": g["property"],
+                    "triggered": prop_id in triggered,
+                }
+                g.update(new_values)
+
+        def recursive_update(g):
+            if isinstance(g, (tuple, list)):
+                for i in g:
+                    update_args_grouping(i)
+                    recursive_update(i)
+            if isinstance(g, dict):
+                for i in g.values():
+                    update_args_grouping(i)
+                    recursive_update(i)
+
+        recursive_update(grouping)
+
+        return grouping
+
+    # todo not sure whether we need this, but it removes a level of nesting so
+    #  you don't need to use `.value` to get the value.
+    @property
+    @has_context
+    def args_grouping_values(self):
+        grouping = getattr(flask.g, "args_grouping", {})
+        grouping = deepcopy(grouping)
+
+        def recursive_update(g):
+            if isinstance(g, (tuple, list)):
+                for i in g:
+                    recursive_update(i)
+            if isinstance(g, dict):
+                for k, v in g.items():
+                    if isinstance(v, dict) and "id" in v:
+                        g[k] = v["value"]
+                    recursive_update(v)
+
+        recursive_update(grouping)
+        return grouping
 
     @property
     @has_context
diff --git a/dash/_grouping.py b/dash/_grouping.py
index 89d62de8aa..790c666fb5 100644
--- a/dash/_grouping.py
+++ b/dash/_grouping.py
@@ -14,6 +14,7 @@
 
 """
 from dash.exceptions import InvalidCallbackReturnValue
+from ._utils import AttributeDict
 
 
 def flatten_grouping(grouping, schema=None):
@@ -127,14 +128,14 @@ def map_grouping(fn, grouping):
         return [map_grouping(fn, g) for g in grouping]
 
     if isinstance(grouping, dict):
-        return {k: map_grouping(fn, g) for k, g in grouping.items()}
+        return AttributeDict({k: map_grouping(fn, g) for k, g in grouping.items()})
 
     return fn(grouping)
 
 
 def make_grouping_by_key(schema, source, default=None):
     """
-    Create a grouping from a schema by ujsing the schema's scalar values to look up
+    Create a grouping from a schema by using the schema's scalar values to look up
     items in the provided source object.
 
     :param schema: A grouping of potential keys in source
diff --git a/dash/_utils.py b/dash/_utils.py
index 31de7e88cb..e5397e2088 100644
--- a/dash/_utils.py
+++ b/dash/_utils.py
@@ -159,7 +159,7 @@ def stringify_id(id_):
 
 
 def inputs_to_dict(inputs_list):
-    inputs = {}
+    inputs = AttributeDict()
     for i in inputs_list:
         inputsi = i if isinstance(i, list) else [i]
         for ii in inputsi:
diff --git a/dash/_validate.py b/dash/_validate.py
index 0318c16d22..b8613126c3 100644
--- a/dash/_validate.py
+++ b/dash/_validate.py
@@ -136,6 +136,11 @@ def validate_and_group_input_args(flat_args, arg_index_grouping):
     if isinstance(arg_index_grouping, dict):
         func_args = []
         func_kwargs = args_grouping
+        for key in func_kwargs:
+            if not key.isidentifier():
+                raise exceptions.CallbackException(
+                    f"{key} is not a valid Python variable name"
+                )
     elif isinstance(arg_index_grouping, (tuple, list)):
         func_args = list(args_grouping)
         func_kwargs = {}
diff --git a/dash/dash.py b/dash/dash.py
index c0b6cb410d..210ce6931a 100644
--- a/dash/dash.py
+++ b/dash/dash.py
@@ -1275,6 +1275,7 @@ def callback(_triggers, user_store_data, user_callback_args):
 
     def dispatch(self):
         body = flask.request.get_json()
+
         flask.g.inputs_list = inputs = body.get(  # pylint: disable=assigning-non-slot
             "inputs", []
         )
@@ -1309,9 +1310,11 @@ def dispatch(self):
             # Add args_grouping
             inputs_state_indices = cb["inputs_state_indices"]
             inputs_state = inputs + state
+            inputs_state = [AttributeDict(i) for i in inputs_state]
             args_grouping = map_grouping(
                 lambda ind: inputs_state[ind], inputs_state_indices
             )
+
             flask.g.args_grouping = args_grouping  # pylint: disable=assigning-non-slot
             flask.g.using_args_grouping = (  # pylint: disable=assigning-non-slot
                 not isinstance(inputs_state_indices, int)

From 2801e61c6955597c9dd2b871db3909a392b2436b Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Fri, 4 Mar 2022 10:04:42 -0700
Subject: [PATCH 04/13] clean-up and fix for pmc

---
 dash/_callback_context.py |  9 ++++-----
 dash/_utils.py            | 10 ++++++++++
 dash/dash.py              |  4 +++-
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/dash/_callback_context.py b/dash/_callback_context.py
index 879bf209e0..a43d3a828f 100644
--- a/dash/_callback_context.py
+++ b/dash/_callback_context.py
@@ -5,6 +5,7 @@
 import flask
 
 from . import exceptions
+from ._utils import stringify_id
 
 
 def has_context(func):
@@ -76,14 +77,12 @@ def args_grouping(self):
 
         def update_args_grouping(g):
             if isinstance(g, dict) and "id" in g:
-                prop_id = ".".join((g["id"], g["property"]))
+                str_id = stringify_id(g["id"])
+                prop_id = "{}.{}".format(str_id, g["property"])
 
                 new_values = {
                     "value": g.get("value"),
-                    "id": g["id"]
-                    if not g["id"].startswith("{")
-                    else json.loads(g["id"]),
-                    "property": g["property"],
+                    "str_id": str_id,
                     "triggered": prop_id in triggered,
                 }
                 g.update(new_values)
diff --git a/dash/_utils.py b/dash/_utils.py
index e5397e2088..ccc5072b0d 100644
--- a/dash/_utils.py
+++ b/dash/_utils.py
@@ -168,6 +168,16 @@ def inputs_to_dict(inputs_list):
     return inputs
 
 
+def convert_to_AttributeDict(nested_list):
+    new_dict = []
+    for i in nested_list:
+        if isinstance(i, dict):
+            new_dict.append(AttributeDict(i))
+        else:
+            new_dict.append([AttributeDict(ii) for ii in i])
+    return new_dict
+
+
 def inputs_to_vals(inputs):
     return [
         [ii.get("value") for ii in i] if isinstance(i, list) else i.get("value")
diff --git a/dash/dash.py b/dash/dash.py
index 210ce6931a..834a3e0568 100644
--- a/dash/dash.py
+++ b/dash/dash.py
@@ -48,6 +48,7 @@
     patch_collections_abc,
     split_callback_id,
     to_json,
+    convert_to_AttributeDict,
 )
 from . import _callback
 from . import _get_paths
@@ -1310,7 +1311,8 @@ def dispatch(self):
             # Add args_grouping
             inputs_state_indices = cb["inputs_state_indices"]
             inputs_state = inputs + state
-            inputs_state = [AttributeDict(i) for i in inputs_state]
+            inputs_state = convert_to_AttributeDict(inputs_state)
+
             args_grouping = map_grouping(
                 lambda ind: inputs_state[ind], inputs_state_indices
             )

From 1d957eab1880c2dbfe2d43107e7666e943d8217a Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Fri, 4 Mar 2022 12:57:22 -0700
Subject: [PATCH 05/13] fixed test

---
 tests/integration/callbacks/test_wildcards.py | 39 +++++++++++++++++--
 1 file changed, 35 insertions(+), 4 deletions(-)

diff --git a/tests/integration/callbacks/test_wildcards.py b/tests/integration/callbacks/test_wildcards.py
index 7359c55671..4f5a403e12 100644
--- a/tests/integration/callbacks/test_wildcards.py
+++ b/tests/integration/callbacks/test_wildcards.py
@@ -1,6 +1,7 @@
 import pytest
 import re
 from selenium.webdriver.common.keys import Keys
+import json
 
 from dash.testing import wait
 import dash
@@ -10,6 +11,12 @@
 from tests.assets.grouping_app import grouping_app
 
 
+def stringify_id(id_):
+    if isinstance(id_, dict):
+        return json.dumps(id_, sort_keys=True, separators=(",", ":"))
+    return id_
+
+
 def css_escape(s):
     sel = re.sub("[\\{\\}\\\"\\'.:,]", lambda m: "\\" + m.group(0), s)
     print(sel)
@@ -413,14 +420,38 @@ def assert_callback_context(items_text):
         args_grouping = dict(
             items=dict(
                 all=[
-                    {"id": {"item": i}, "property": "children", "value": text}
+                    {
+                        "id": {"item": i},
+                        "property": "children",
+                        "value": text,
+                        "str_id": stringify_id({"item": i}),
+                        "triggered": False,
+                    }
                     for i, text in enumerate(items_text[:-1])
                 ],
-                new=dict(id="new-item", property="value", value=items_text[-1]),
+                new=dict(
+                    id="new-item",
+                    property="value",
+                    value=items_text[-1],
+                    str_id="new-item",
+                    triggered=False,
+                ),
             ),
             triggers=[
-                {"id": "add", "property": "n_clicks", "value": len(items_text)},
-                {"id": "new-item", "property": "n_submit"},
+                {
+                    "id": "add",
+                    "property": "n_clicks",
+                    "value": len(items_text),
+                    "str_id": "add",
+                    "triggered": True,
+                },
+                {
+                    "id": "new-item",
+                    "property": "n_submit",
+                    "value": None,
+                    "str_id": "new-item",
+                    "triggered": False,
+                },
             ],
         )
         dash_duo.wait_for_text_to_equal("#cc-args-grouping", repr(args_grouping))

From 6fc9900b342707ef239e4f2ef5a744375cc1bf51 Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Sun, 6 Mar 2022 19:10:20 -0700
Subject: [PATCH 06/13] added AttributeDict to PMC ids added to .start method
 in AttributeDict

---
 dash/_callback_context.py | 9 ++++++---
 dash/_utils.py            | 2 ++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/dash/_callback_context.py b/dash/_callback_context.py
index a43d3a828f..3ed4b903f7 100644
--- a/dash/_callback_context.py
+++ b/dash/_callback_context.py
@@ -5,7 +5,7 @@
 import flask
 
 from . import exceptions
-from ._utils import stringify_id
+from ._utils import stringify_id, AttributeDict
 
 
 def has_context(func):
@@ -60,12 +60,12 @@ def triggered(self):
     @has_context
     def triggered_ids(self):
         triggered = getattr(flask.g, "triggered_inputs", [])
-        ids = {}
+        ids = AttributeDict({})
         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)
+                ids[item["prop_id"]] = AttributeDict(json.loads(component_id))
         return ids
 
     @property
@@ -84,6 +84,9 @@ def update_args_grouping(g):
                     "value": g.get("value"),
                     "str_id": str_id,
                     "triggered": prop_id in triggered,
+                    "id": AttributeDict(g["id"])
+                    if isinstance(g["id"], dict)
+                    else g["id"],
                 }
                 g.update(new_values)
 
diff --git a/dash/_utils.py b/dash/_utils.py
index ccc5072b0d..1c658b09e3 100644
--- a/dash/_utils.py
+++ b/dash/_utils.py
@@ -119,6 +119,8 @@ def first(self, *names):
             value = self.get(name)
             if value:
                 return value
+        if names == ():
+            return next(iter(self), {})
 
 
 def create_callback_id(output):

From 49a5e59ee464917f4a5a196548e1e9185dfcbd64 Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Thu, 10 Mar 2022 10:33:31 -0700
Subject: [PATCH 07/13] added triggered_id and renamed triggered_prop_ids

---
 dash/_callback_context.py | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/dash/_callback_context.py b/dash/_callback_context.py
index 3ed4b903f7..48afd39c19 100644
--- a/dash/_callback_context.py
+++ b/dash/_callback_context.py
@@ -58,7 +58,7 @@ def triggered(self):
 
     @property
     @has_context
-    def triggered_ids(self):
+    def triggered_prop_ids(self):
         triggered = getattr(flask.g, "triggered_inputs", [])
         ids = AttributeDict({})
         for item in triggered:
@@ -68,6 +68,15 @@ def triggered_ids(self):
                 ids[item["prop_id"]] = AttributeDict(json.loads(component_id))
         return ids
 
+    @property
+    @has_context
+    def triggered_id(self):
+        component_id = None
+        if self.triggered:
+            prop_id = self.triggered_prop_ids.first()
+            component_id = self.triggered_prop_ids[prop_id]
+        return component_id
+
     @property
     @has_context
     def args_grouping(self):

From 67f56d09d70e77701d2ae9a002aa330202da118b Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Sun, 13 Mar 2022 14:50:44 -0700
Subject: [PATCH 08/13] added docstrings

---
 dash/_callback_context.py | 67 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/dash/_callback_context.py b/dash/_callback_context.py
index 48afd39c19..c5ce432fcc 100644
--- a/dash/_callback_context.py
+++ b/dash/_callback_context.py
@@ -50,6 +50,18 @@ def states(self):
     @property
     @has_context
     def triggered(self):
+        """
+         Returns a list of all the Input props that changed and caused the callback to execute. It is empty when the callback is
+          called on initial load, unless an Input prop got its value from another initial callback. Callbacks triggered
+           by user actions typically have one item in triggered, unless the same action changes two props at once or
+            the callback has several Input props that are all modified by another callback based on a single user action.
+
+        Example:  To get the id of the component that triggered the callback:
+        `component_id = ctx.triggered[0]['prop_id'].split('.')[0]`
+
+        Example:  To detect initial call, empty triggered is not really empty, it's falsy so that you can use:
+        `if ctx.triggered:`
+        """
         # For backward compatibility: previously `triggered` always had a
         # value - to avoid breaking existing apps, add a dummy item but
         # make the list still look falsy. So `if ctx.triggered` will make it
@@ -59,6 +71,26 @@ def triggered(self):
     @property
     @has_context
     def triggered_prop_ids(self):
+        """
+        Returns a dictionary of all the Input props that changed and caused the callback to execute. It is empty when the callback is
+          called on initial load, unless an Input prop got its value from another initial callback. Callbacks triggered
+           by user actions typically have one item in triggered, unless the same action changes two props at once or
+            the callback has several Input props that are all modified by another callback based on a single user action.
+
+        triggered_prop_ids (dict):
+        - keys (str) : the triggered "prop_id" composed of "component_id.component_property"
+        - values (str or dict): the id of the component that triggered the callback. Will be the dict id for pattern matching callbacks
+
+        Example - regular callback
+        {"btn-1.n_clicks": "btn-1"}
+
+        Example - pattern matching callbacks:
+        {'{"index":0,"type":"filter-dropdown"}.value': {"index":0,"type":"filter-dropdown"}}
+
+        Example usage:
+        `if "btn-1.n_clicks" in ctx.triggered_prop_ids:
+            do_something()`
+        """
         triggered = getattr(flask.g, "triggered_inputs", [])
         ids = AttributeDict({})
         for item in triggered:
@@ -71,6 +103,17 @@ def triggered_prop_ids(self):
     @property
     @has_context
     def triggered_id(self):
+        """
+        Returns the component id (str or dict) of the Input component that triggered the callback.
+
+        Note - use `triggered_prop_ids` if you need both the component id and the prop that triggered the callback or if
+        multiple Inputs triggered the callback.
+
+        Example usage:
+        `if "btn-1" == ctx.triggered_id:
+            do_something()`
+
+        """
         component_id = None
         if self.triggered:
             prop_id = self.triggered_prop_ids.first()
@@ -80,6 +123,30 @@ def triggered_id(self):
     @property
     @has_context
     def args_grouping(self):
+        """
+        args_grouping is a dict of the inputs used with flexible callback signatures. The keys are the variable names
+        and the values are dictionaries containing:
+        - “id”: (string or dict) the component id. If it’s a pattern matching id, it will be a dict.
+        - “id_str”: (str) for pattern matching ids, it’s the strigified dict id with no white spaces.
+        - “property”: (str) The component property used in the callback.
+        - “value”: the value of the component property at the time the callback was fired.
+        - “triggered”: (bool)Whether this input triggered the callback.
+
+        Example usage:
+        @app.callback(
+            Output("container", "children"),
+            inputs=dict(btn1=Input("btn-1", "n_clicks"), btn2=Input("btn-2", "n_clicks")),
+        )
+        def display(btn1, btn2):
+            c = ctx.args_grouping
+            if c.btn1.triggered:
+                return f"Button 1 clicked {btn1} times"
+            elif c.btn2.triggered:
+                return f"Button 2 clicked {btn2} times"
+            else:
+               return "No clicks yet"
+
+        """
         triggered = getattr(flask.g, "triggered_inputs", [])
         triggered = [item["prop_id"] for item in triggered]
         grouping = getattr(flask.g, "args_grouping", {})

From df6874a214fee97b108627b084d098d640086cba Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Sun, 13 Mar 2022 16:09:10 -0700
Subject: [PATCH 09/13] fixed tests

---
 tests/integration/callbacks/test_callback_context.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tests/integration/callbacks/test_callback_context.py b/tests/integration/callbacks/test_callback_context.py
index 4ffaf6a278..1080687a2e 100644
--- a/tests/integration/callbacks/test_callback_context.py
+++ b/tests/integration/callbacks/test_callback_context.py
@@ -346,7 +346,8 @@ def on_click(*args):
         if not ctx.triggered:
             raise PreventUpdate
         for btn in btns:
-            if btn in ctx.triggered_ids.values():
+            if btn in ctx.triggered_prop_ids.values():
+                assert btn == ctx.triggered_id
                 return f"Just clicked {btn}"
 
     dash_duo.start_server(app)
@@ -372,11 +373,15 @@ def test_cbcx008_triggered_id_pmc(dash_duo):
     )
     def func(n_clicks):
         if ctx.triggered:
-            triggered_id, dict_id = next(iter(ctx.triggered_ids.items()))
+            triggered_id, dict_id = next(iter(ctx.triggered_prop_ids.items()))
+
+            assert dict_id == ctx.triggered_id
+
             if dict_id == {"type": "btn", "index": "myindex"}:
                 return dict_id["index"]
 
     dash_duo.start_server(app)
+
     dash_duo.find_element(
         '#\\{\\"index\\"\\:\\"myindex\\"\\,\\"type\\"\\:\\"btn\\"\\}'
     ).click()

From 2d33fc270fc9ee4c5bd60a5e2ca700d974301a8a Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Thu, 21 Apr 2022 14:04:18 -0700
Subject: [PATCH 10/13] update after review

---
 dash/__init__.py          |  3 ++-
 dash/_callback_context.py | 20 +++++++++++---------
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/dash/__init__.py b/dash/__init__.py
index 1b64bc170a..c90d6463c7 100644
--- a/dash/__init__.py
+++ b/dash/__init__.py
@@ -19,10 +19,11 @@
 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, ctx  # noqa: F401,E402
+from ._callback_context import callback_context  # noqa: F401,E402
 from ._callback import callback, clientside_callback  # noqa: F401,E402
 from ._get_paths import (  # noqa: F401,E402
     get_asset_url,
     get_relative_path,
     strip_relative_path,
 )
+ctx = callback_context
diff --git a/dash/_callback_context.py b/dash/_callback_context.py
index c5ce432fcc..25e09d0da8 100644
--- a/dash/_callback_context.py
+++ b/dash/_callback_context.py
@@ -51,10 +51,11 @@ def states(self):
     @has_context
     def triggered(self):
         """
-         Returns a list of all the Input props that changed and caused the callback to execute. It is empty when the callback is
-          called on initial load, unless an Input prop got its value from another initial callback. Callbacks triggered
-           by user actions typically have one item in triggered, unless the same action changes two props at once or
-            the callback has several Input props that are all modified by another callback based on a single user action.
+        Returns a list of all the Input props that changed and caused the callback to execute. It is empty when the
+        callback is called on initial load, unless an Input prop got its value from another initial callback.
+        Callbacks triggered by user actions typically have one item in triggered, unless the same action changes
+        two props at once or the callback has several Input props that are all modified by another callback based on
+        a single user action.
 
         Example:  To get the id of the component that triggered the callback:
         `component_id = ctx.triggered[0]['prop_id'].split('.')[0]`
@@ -72,10 +73,11 @@ def triggered(self):
     @has_context
     def triggered_prop_ids(self):
         """
-        Returns a dictionary of all the Input props that changed and caused the callback to execute. It is empty when the callback is
-          called on initial load, unless an Input prop got its value from another initial callback. Callbacks triggered
-           by user actions typically have one item in triggered, unless the same action changes two props at once or
-            the callback has several Input props that are all modified by another callback based on a single user action.
+        Returns a dictionary of all the Input props that changed and caused the callback to execute. It is empty when
+        the callback is called on initial load, unless an Input prop got its value from another initial callback.
+        Callbacks triggered by user actions typically have one item in triggered, unless the same action changes
+        two props at once or the callback has several Input props that are all modified by another callback based
+        on a single user action.
 
         triggered_prop_ids (dict):
         - keys (str) : the triggered "prop_id" composed of "component_id.component_property"
@@ -287,4 +289,4 @@ def using_outputs_grouping(self):
 
 
 callback_context = CallbackContext()
-ctx = CallbackContext()
+

From d7698f1d1ba728e528f411ff85505379f54b1eb5 Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Thu, 21 Apr 2022 14:41:58 -0700
Subject: [PATCH 11/13] added changlog and lint

---
 CHANGELOG.md              | 8 ++++++++
 dash/_callback_context.py | 1 -
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index eb46a1c33d..c1005ccb77 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,14 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+### Added
+- [#1952](https://github.com/plotly/dash/pull/1952) Improved callback_context
+  - Closes [#1818](https://github.com/plotly/dash/issues/1818) Closes [#1054](https://github.com/plotly/dash/issues/1054)
+  - adds `dash.ctx`, a more concise name for `dash.callback_context`
+  - adds `ctx.triggered_prop_ids`, a dictionary of the component ids and props that triggered the callback.
+  - adds `ctx.triggered_id`, the `id` of the component that triggered the callback.
+  - adds `ctx.args_grouping`, a dict of the inputs used with flexible callback signatures.
+
 ### Fixed
 
 - [#2015](https://github.com/plotly/dash/pull/2015) Fix bug [#1854](https://github.com/plotly/dash/issues/1854) in which the combination of row_selectable="single or multi" and filter_action="native" caused the JS error.
diff --git a/dash/_callback_context.py b/dash/_callback_context.py
index bd31784c8f..134723b115 100644
--- a/dash/_callback_context.py
+++ b/dash/_callback_context.py
@@ -287,4 +287,3 @@ def using_outputs_grouping(self):
 
 
 callback_context = CallbackContext()
-

From 47b7af9c2793328343062cc8d1dd69ea4a3f0164 Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Thu, 21 Apr 2022 15:49:00 -0700
Subject: [PATCH 12/13] lint again

---
 dash/_callback_context.py | 2 +-
 dash/_utils.py            | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/dash/_callback_context.py b/dash/_callback_context.py
index 134723b115..8722f2b6d1 100644
--- a/dash/_callback_context.py
+++ b/dash/_callback_context.py
@@ -154,7 +154,7 @@ def display(btn1, btn2):
         def update_args_grouping(g):
             if isinstance(g, dict) and "id" in g:
                 str_id = stringify_id(g["id"])
-                prop_id = "{}.{}".format(str_id, g["property"])
+                prop_id = f"{str_id}.{g['propery']}"
 
                 new_values = {
                     "value": g.get("value"),
diff --git a/dash/_utils.py b/dash/_utils.py
index 7b937b3ff6..aa0470f43d 100644
--- a/dash/_utils.py
+++ b/dash/_utils.py
@@ -119,7 +119,7 @@ def first(self, *names):
             value = self.get(name)
             if value:
                 return value
-        if names == ():
+        if not names:
             return next(iter(self), {})
 
 

From ea493c5a1cde06e888638c995821edf4f7e3c125 Mon Sep 17 00:00:00 2001
From: AnnMarieW <amward@fastmail.com>
Date: Thu, 21 Apr 2022 16:58:38 -0700
Subject: [PATCH 13/13] lint again and again

---
 dash/_callback_context.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dash/_callback_context.py b/dash/_callback_context.py
index 8722f2b6d1..20f0e887b6 100644
--- a/dash/_callback_context.py
+++ b/dash/_callback_context.py
@@ -154,7 +154,7 @@ def display(btn1, btn2):
         def update_args_grouping(g):
             if isinstance(g, dict) and "id" in g:
                 str_id = stringify_id(g["id"])
-                prop_id = f"{str_id}.{g['propery']}"
+                prop_id = f"{str_id}.{g['property']}"
 
                 new_values = {
                     "value": g.get("value"),