add current scope variables when evaluating an expression (#2250)

* add current scope variables when evaluating an expression
resolves #2242

* - add locals only when evaluating a lambda
- with test

* fab's comment

---------

Co-authored-by: Fred Lefévère-Laoide <[email protected]>

taipy/gui/utils/_evaluator.py

@@ -256,6 +256,8 @@ def evaluate_expr(
             # evaluate expressions
             ctx: t.Dict[str, t.Any] = {}
             ctx.update(self.__global_ctx)
+            if lambda_expr:
+                ctx.update(gui._get_locals_bind())
             # entries in var_val are not always seen (NameError) when passed as locals
             ctx.update(var_val)
             with gui._get_authorization():

tests/gui/gui_specific/test_evaluator.py

@@ -0,0 +1,25 @@
+# Copyright 2021-2024 Avaiga Private Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+# the License. You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+# an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations under the License.
+
+from taipy.gui import Gui
+from taipy.gui.utils._evaluator import _Evaluator
+
+
+def _identity(x):
+    return x
+
+def test_evaluate_expr_lambda_from_element(gui: Gui, test_client, helpers):
+    gui._Gui__evaluator = _Evaluator({}, []) # type: ignore[attr-defined]
+    gui._Gui__locals_context.add("a_module", {"identity": _identity}) # type: ignore[attr-defined]
+    with gui._set_locals_context("a_module"):
+        evaluated_expr: str = gui._evaluate_expr("lambda x: identity(x)", lambda_expr=True)
+        assert evaluated_expr.startswith("__lambda_")
+        assert evaluated_expr.endswith("_TPMDL_0")