🥅 Improve error management with new '_ready' traitlets

js/widget.js

@@ -29,6 +29,7 @@ function initAladinLite(model, el) {
     y: twoAxisFoV[1],
   });
   model.set("_wcs", aladin.getViewWCS());
+  model.set("_ready", true);
   model.save_changes();
 
   el.appendChild(aladinDiv);

src/ipyaladin/utils/_coordinate_parser.py

@@ -4,10 +4,6 @@
 from astropy.coordinates import SkyCoord, Angle
 import re
 
-from astropy.coordinates.name_resolve import NameResolveError
-
-from ipyaladin.utils.exceptions import WidgetCommunicationError
-
 OK_STATUS_CODE = 200
 
 
@@ -30,14 +26,7 @@ def parse_coordinate_string(string: str, body: str = "sky") -> SkyCoord:
     """
     if not _is_coordinate_string(string):
         if body == "sky":
-            try:
-                return SkyCoord.from_name(string)
-            except NameResolveError as e:
-                raise WidgetCommunicationError(
-                    f"Either '{string}' is not a valid object name, or "
-                    f"the survey body type is not yet defined so you "
-                    f"need to set the target from another cell."
-                ) from e
+            return SkyCoord.from_name(string)
         return _from_name_on_planet(string, body)
     coordinates: Tuple[str, str] = _split_coordinate_string(string)
     # Parse ra and dec to astropy Angle objects

src/ipyaladin/widget.py

@@ -14,6 +14,7 @@
 
 import anywidget
 from astropy.coordinates import SkyCoord, Angle
+from astropy.coordinates.name_resolve import NameResolveError
 from astropy.table.table import QTable
 from astropy.table import Table
 from astropy.io import fits as astropy_fits
@@ -190,6 +191,10 @@ class Aladin(anywidget.AnyWidget):
     )
 
     # Values
+    _ready = Bool(
+        False,
+        help="A private trait that stores the readiness of the widget.",
+    ).tag(sync=True)
     _wcs = traitlets.Dict().tag(sync=True)
     _fov_xy = traitlets.Dict().tag(sync=True)
 
@@ -345,7 +350,15 @@ def target(self) -> SkyCoord:
     @target.setter
     def target(self, target: Union[str, SkyCoord]) -> None:
         if isinstance(target, str):  # If the target is str, parse it
-            target = parse_coordinate_string(target, self._survey_body)
+            try:
+                target = parse_coordinate_string(target, self._survey_body)
+            except NameResolveError as e:
+                if not self._ready:
+                    raise WidgetCommunicationError(
+                        f"Either '{target}' is not a valid object name, or "
+                        f"the survey body type is not yet defined so you "
+                        f"need to set the target from another cell."
+                    ) from e
         elif not isinstance(target, SkyCoord):  # If the target is not str or SkyCoord
             raise ValueError(
                 "target must be a string or an astropy.coordinates.SkyCoord object"