Preserve form field values in eggs.py on validation errors

When a validation error occurs in the harvest or sell forms, the
entered field values are now preserved and redisplayed to the user.
This prevents the frustration of having to re-enter all values after
a single field fails validation.

Template changes (eggs.py):
- Added default_* parameters to harvest_form and sell_form
- Updated LabelInput/LabelTextArea fields to use these values

Route changes (routes/eggs.py):
- Updated _render_harvest_error to accept quantity and notes
- Updated _render_sell_error to accept quantity, total_price_cents,
  buyer, and notes
- All error return calls now pass form values through

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/animaltrack/web/routes/eggs.py

@@ -365,7 +365,14 @@ async def product_collected(request: Request, session):
     # Validate location_id
     if not location_id:
         return _render_harvest_error(
-            request, db, locations, products, None, "Please select a location"
+            request,
+            db,
+            locations,
+            products,
+            None,
+            "Please select a location",
+            quantity=quantity_str,
+            notes=notes,
         )
 
     # Validate quantity
@@ -373,12 +380,26 @@ async def product_collected(request: Request, session):
         quantity = int(quantity_str)
     except ValueError:
         return _render_harvest_error(
-            request, db, locations, products, location_id, "Quantity must be a number"
+            request,
+            db,
+            locations,
+            products,
+            location_id,
+            "Quantity must be a number",
+            quantity=quantity_str,
+            notes=notes,
         )
 
     if quantity < 0:
         return _render_harvest_error(
-            request, db, locations, products, location_id, "Quantity cannot be negative"
+            request,
+            db,
+            locations,
+            products,
+            location_id,
+            "Quantity cannot be negative",
+            quantity=quantity_str,
+            notes=notes,
         )
 
     # Get timestamp - use provided or current (supports backdating)
@@ -389,7 +410,14 @@ async def product_collected(request: Request, session):
 
     if not resolved_ids:
         return _render_harvest_error(
-            request, db, locations, products, location_id, "No ducks at this location"
+            request,
+            db,
+            locations,
+            products,
+            location_id,
+            "No ducks at this location",
+            quantity=quantity_str,
+            notes=notes,
         )
 
     # Create product service
@@ -422,7 +450,16 @@ async def product_collected(request: Request, session):
             route="/actions/product-collected",
         )
     except ValidationError as e:
-        return _render_harvest_error(request, db, locations, products, location_id, str(e))
+        return _render_harvest_error(
+            request,
+            db,
+            locations,
+            products,
+            location_id,
+            str(e),
+            quantity=quantity_str,
+            notes=notes,
+        )
 
     # Save user defaults (only if user exists in database)
     if UserRepository(db).get(actor):
@@ -486,19 +523,48 @@ async def product_sold(request: Request, session):
 
     # Validate product_code
     if not product_code:
-        return _render_sell_error(request, db, locations, products, None, "Please select a product")
+        return _render_sell_error(
+            request,
+            db,
+            locations,
+            products,
+            None,
+            "Please select a product",
+            quantity=quantity_str,
+            total_price_cents=total_price_str,
+            buyer=buyer,
+            notes=notes,
+        )
 
     # Validate quantity
     try:
         quantity = int(quantity_str)
     except ValueError:
         return _render_sell_error(
-            request, db, locations, products, product_code, "Quantity must be a number"
+            request,
+            db,
+            locations,
+            products,
+            product_code,
+            "Quantity must be a number",
+            quantity=quantity_str,
+            total_price_cents=total_price_str,
+            buyer=buyer,
+            notes=notes,
         )
 
     if quantity < 1:
         return _render_sell_error(
-            request, db, locations, products, product_code, "Quantity must be at least 1"
+            request,
+            db,
+            locations,
+            products,
+            product_code,
+            "Quantity must be at least 1",
+            quantity=quantity_str,
+            total_price_cents=total_price_str,
+            buyer=buyer,
+            notes=notes,
         )
 
     # Validate total_price_cents
@@ -506,12 +572,30 @@ async def product_sold(request: Request, session):
         total_price_cents = int(total_price_str)
     except ValueError:
         return _render_sell_error(
-            request, db, locations, products, product_code, "Total price must be a number"
+            request,
+            db,
+            locations,
+            products,
+            product_code,
+            "Total price must be a number",
+            quantity=quantity_str,
+            total_price_cents=total_price_str,
+            buyer=buyer,
+            notes=notes,
         )
 
     if total_price_cents < 0:
         return _render_sell_error(
-            request, db, locations, products, product_code, "Total price cannot be negative"
+            request,
+            db,
+            locations,
+            products,
+            product_code,
+            "Total price cannot be negative",
+            quantity=quantity_str,
+            total_price_cents=total_price_str,
+            buyer=buyer,
+            notes=notes,
         )
 
     # Get timestamp - use provided or current (supports backdating)
@@ -544,7 +628,18 @@ async def product_sold(request: Request, session):
             route="/actions/product-sold",
         )
     except ValidationError as e:
-        return _render_sell_error(request, db, locations, products, product_code, str(e))
+        return _render_sell_error(
+            request,
+            db,
+            locations,
+            products,
+            product_code,
+            str(e),
+            quantity=quantity_str,
+            total_price_cents=total_price_str,
+            buyer=buyer,
+            notes=notes,
+        )
 
     # Add success toast with link to event
     add_toast(
@@ -573,8 +668,17 @@ async def product_sold(request: Request, session):
     )
 
 
-def _render_harvest_error(request, db, locations, products, selected_location_id, error_message):
+def _render_harvest_error(
-    """Render harvest form with error message.
+    request,
+    db,
+    locations,
+    products,
+    selected_location_id,
+    error_message,
+    quantity: str | None = None,
+    notes: str | None = None,
+):
+    """Render harvest form with error message and preserved field values.
 
     Args:
         request: The HTTP request.
@@ -583,6 +687,8 @@ def _render_harvest_error(request, db, locations, products, selected_location_id
         products: List of sellable products.
         selected_location_id: Currently selected location.
         error_message: Error message to display.
+        quantity: Quantity value to preserve.
+        notes: Notes value to preserve.
 
     Returns:
         HTMLResponse with 422 status.
@@ -600,6 +706,8 @@ def _render_harvest_error(request, db, locations, products, selected_location_id
                     harvest_error=error_message,
                     harvest_action=product_collected,
                     sell_action=product_sold,
+                    harvest_quantity=quantity,
+                    harvest_notes=notes,
                     **display_data,
                 ),
                 title="Eggs - AnimalTrack",
@@ -610,8 +718,19 @@ def _render_harvest_error(request, db, locations, products, selected_location_id
     )
 
 
-def _render_sell_error(request, db, locations, products, selected_product_code, error_message):
+def _render_sell_error(
-    """Render sell form with error message.
+    request,
+    db,
+    locations,
+    products,
+    selected_product_code,
+    error_message,
+    quantity: str | None = None,
+    total_price_cents: str | None = None,
+    buyer: str | None = None,
+    notes: str | None = None,
+):
+    """Render sell form with error message and preserved field values.
 
     Args:
         request: The HTTP request.
@@ -620,6 +739,10 @@ def _render_sell_error(request, db, locations, products, selected_product_code,
         products: List of sellable products.
         selected_product_code: Currently selected product code.
         error_message: Error message to display.
+        quantity: Quantity value to preserve.
+        total_price_cents: Total price value to preserve.
+        buyer: Buyer value to preserve.
+        notes: Notes value to preserve.
 
     Returns:
         HTMLResponse with 422 status.
@@ -637,6 +760,10 @@ def _render_sell_error(request, db, locations, products, selected_product_code,
                     sell_error=error_message,
                     harvest_action=product_collected,
                     sell_action=product_sold,
+                    sell_quantity=quantity,
+                    sell_total_price_cents=total_price_cents,
+                    sell_buyer=buyer,
+                    sell_notes=notes,
                     **display_data,
                 ),
                 title="Eggs - AnimalTrack",

src/animaltrack/web/templates/eggs.py

@@ -37,6 +37,13 @@ def eggs_page(
     cost_per_egg: float | None = None,
     sales_stats: dict | None = None,
     location_names: dict[str, str] | None = None,
+    # Field value preservation on errors
+    harvest_quantity: str | None = None,
+    harvest_notes: str | None = None,
+    sell_quantity: str | None = None,
+    sell_total_price_cents: str | None = None,
+    sell_buyer: str | None = None,
+    sell_notes: str | None = None,
 ):
     """Create the Eggs page with tabbed forms.
 
@@ -56,6 +63,12 @@ def eggs_page(
         cost_per_egg: 30-day average cost per egg in EUR.
         sales_stats: Dict with 'total_qty', 'total_cents', and 'avg_price_per_egg_cents'.
         location_names: Dict mapping location_id to location name for display.
+        harvest_quantity: Preserved quantity value on error.
+        harvest_notes: Preserved notes value on error.
+        sell_quantity: Preserved quantity value on error.
+        sell_total_price_cents: Preserved total price value on error.
+        sell_buyer: Preserved buyer value on error.
+        sell_notes: Preserved notes value on error.
 
     Returns:
         Page content with tabbed forms.
@@ -85,6 +98,8 @@ def eggs_page(
                     eggs_per_day=eggs_per_day,
                     cost_per_egg=cost_per_egg,
                     location_names=location_names,
+                    default_quantity=harvest_quantity,
+                    default_notes=harvest_notes,
                 ),
                 cls="uk-active" if harvest_active else None,
             ),
@@ -96,6 +111,10 @@ def eggs_page(
                     action=sell_action,
                     recent_events=sell_events,
                     sales_stats=sales_stats,
+                    default_quantity=sell_quantity,
+                    default_total_price_cents=sell_total_price_cents,
+                    default_buyer=sell_buyer,
+                    default_notes=sell_notes,
                 ),
                 cls=None if harvest_active else "uk-active",
             ),
@@ -113,6 +132,8 @@ def harvest_form(
     eggs_per_day: float | None = None,
     cost_per_egg: float | None = None,
     location_names: dict[str, str] | None = None,
+    default_quantity: str | None = None,
+    default_notes: str | None = None,
 ) -> Div:
     """Create the Harvest form for egg collection.
 
@@ -125,6 +146,8 @@ def harvest_form(
         eggs_per_day: 30-day average eggs per day.
         cost_per_egg: 30-day average cost per egg in EUR.
         location_names: Dict mapping location_id to location name for display.
+        default_quantity: Preserved quantity value on error.
+        default_notes: Preserved notes value on error.
 
     Returns:
         Div containing form and recent events section.
@@ -193,6 +216,7 @@ def harvest_form(
             step="1",
             placeholder="Number of eggs",
             required=True,
+            value=default_quantity or "",
         ),
         # Optional notes
         LabelTextArea(
@@ -200,6 +224,7 @@ def harvest_form(
             id="notes",
             name="notes",
             placeholder="Optional notes",
+            value=default_notes or "",
         ),
         # Event datetime picker (for backdating)
         event_datetime_field("harvest_datetime"),
@@ -231,6 +256,10 @@ def sell_form(
     action: Callable[..., Any] | str = "/actions/product-sold",
     recent_events: list[tuple[Event, bool]] | None = None,
     sales_stats: dict | None = None,
+    default_quantity: str | None = None,
+    default_total_price_cents: str | None = None,
+    default_buyer: str | None = None,
+    default_notes: str | None = None,
 ) -> Div:
     """Create the Sell form for recording sales.
 
@@ -241,6 +270,10 @@ def sell_form(
         action: Route function or URL string for form submission.
         recent_events: Recent (Event, is_deleted) tuples, most recent first.
         sales_stats: Dict with 'total_qty' and 'total_cents' for 30-day sales.
+        default_quantity: Preserved quantity value on error.
+        default_total_price_cents: Preserved total price value on error.
+        default_buyer: Preserved buyer value on error.
+        default_notes: Preserved notes value on error.
 
     Returns:
         Div containing form and recent events section.
@@ -315,6 +348,7 @@ def sell_form(
             step="1",
             placeholder="Number of items sold",
             required=True,
+            value=default_quantity or "",
         ),
         # Total price in cents
         LabelInput(
@@ -326,6 +360,7 @@ def sell_form(
             step="1",
             placeholder="Total price in cents",
             required=True,
+            value=default_total_price_cents or "",
         ),
         # Optional buyer
         LabelInput(
@@ -334,6 +369,7 @@ def sell_form(
             name="buyer",
             type="text",
             placeholder="Optional buyer name",
+            value=default_buyer or "",
         ),
         # Optional notes
         LabelTextArea(
@@ -341,6 +377,7 @@ def sell_form(
             id="sell_notes",
             name="notes",
             placeholder="Optional notes",
+            value=default_notes or "",
         ),
         # Event datetime picker (for backdating)
         event_datetime_field("sell_datetime"),