part style property support (#2670)

* part style property support
resolves #2574

* Update taipy/gui/viselements.json

Co-authored-by: Fabien Lelaquais <86590727+FabienLelaquais@users.noreply.github.com>

---------

Co-authored-by: Fred Lefévère-Laoide <Fred.Lefevere-Laoide@Taipy.io>
Co-authored-by: Fabien Lelaquais <86590727+FabienLelaquais@users.noreply.github.com>

Author: 3 people

taipy/gui/_renderers/builder.py

@@ -1200,4 +1200,5 @@ def _build_to_string(self):
         el_str = el_str.replace("<?xml version='1.0' encoding='utf8'?>\n", "")
         el_str = el_str.replace("/>", ">")
         el_str = el_str.replace(">style</TaipyStyle>", "/>")
+        el_str = el_str.replace(f"</{self.__element_name}>", "")
         return el_str, self.__element_name

taipy/gui/viselements.json

@@ -2375,6 +2375,11 @@
                         "name": "hover_text",
                         "type": "dynamic(str)",
                         "doc": "The text that is displayed when the user hovers over the element."
+                    },
+                    {
+                        "name": "style",
+                        "type": "dict",
+                        "doc": "TODO: A dict representing a css description."
                     }
                 ]
             }

tests/gui/builder/control/test_part.py

@@ -19,3 +19,10 @@ def test_part_builder_1(gui: Gui, helpers):
             tgb.text(value="This is a part")  # type: ignore[attr-defined]
     expected_list = ["<Part", "This is a part"]
     helpers.test_control_builder(gui, page, expected_list)
+
+def test_part_builder_with_style(gui: Gui, helpers):
+    with tgb.Page(frame=None) as page:
+        with tgb.part(class_name="class1", style={"background": "red"}):  # type: ignore[attr-defined]
+            tgb.text(value="This is a part")  # type: ignore[attr-defined]
+    expected_list = ["<Part", "This is a part", '<TaipyStyle className="tpcss-']
+    helpers.test_control_builder(gui, page, expected_list)