feat: placeholder labels for split datetime widget (#1150)

Author: lukasvinclav

src/unfold/templates/unfold/widgets/split_datetime.html

@@ -1,9 +1,5 @@
 <div class="datetime flex flex-col gap-2 max-w-2xl lg:flex-row lg:group-[.field-row]:flex-row lg:group-[.field-row]:items-center lg:group-[.field-tabular]:flex-row lg:group-[.field-tabular]:items-center">
     <div class="basis-1/2 flex flex-col lg:group-[.field-row]:flex-row group-[.field-row]:gap-2 lg:group-[.field-tabular]:flex-row group-[.field-tabular]:gap-2">
-        <div class="font-medium mb-2 group-[.field-row]:mb-0 group-[.field-row]:flex group-[.field-row]:items-center group-[.field-tabular]:mb-0 group-[.field-tabular]:flex group-[.field-tabular]:items-center">
-            {{ date_label }}
-        </div>
-
         {% with widget=widget.subwidgets.0 %}
             <div class="flex flex-col min-w-52 relative group-[.field-row]:flex-grow group-[.field-tabular]:flex-grow">
                 {% include widget.template_name %}
@@ -12,10 +8,6 @@
     </div>
 
     <div class="basis-1/2 flex flex-col lg:ml-auto md:mt-0 lg:group-[.field-row]:flex-row group-[.field-row]:gap-2 lg:group-[.field-tabular]:flex-row group-[.field-tabular]:gap-2">
-        <div class="font-medium mb-2 group-[.field-row]:mb-0 group-[.field-row]:flex group-[.field-row]:items-center group-[.field-tabular]:mb-0 group-[.field-tabular]:flex group-[.field-tabular]:items-center">
-            {{ time_label }}
-        </div>
-
         {% with widget=widget.subwidgets.1 %}
             <div class="flex flex-col min-w-52 relative group-[.field-row]:flex-grow group-[.field-tabular]:flex-grow">
                 {% include widget.template_name %}

src/unfold/widgets.py

@@ -493,7 +493,10 @@ class UnfoldAdminSplitDateTimeWidget(AdminSplitDateTime):
     template_name = "unfold/widgets/split_datetime.html"
 
     def __init__(self, attrs: Optional[dict[str, Any]] = None) -> None:
-        widgets = [UnfoldAdminDateWidget, UnfoldAdminTimeWidget]
+        widgets = [
+            UnfoldAdminDateWidget(attrs={"placeholder": _("Date")}),
+            UnfoldAdminTimeWidget(attrs={"placeholder": _("Time")}),
+        ]
         MultiWidget.__init__(self, widgets, attrs)