From 1a2a75880d038b514687fdfdaee1a336c72132da Mon Sep 17 00:00:00 2001
From: Tobias Kunze <r@rixx.de>
Date: Thu, 11 Sep 2025 14:58:08 +0200
Subject: [PATCH] Fix JSON re-parsing in re-rendered invalid form

---
 src/servala/frontend/forms/widgets.py  | 49 ++++++++++++++++++++------
 src/servala/static/js/dynamic-array.js |  5 ++-
 2 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/src/servala/frontend/forms/widgets.py b/src/servala/frontend/forms/widgets.py
index 16e19bf..d67030f 100644
--- a/src/servala/frontend/forms/widgets.py
+++ b/src/servala/frontend/forms/widgets.py
@@ -48,18 +48,31 @@ class DynamicArrayWidget(forms.Widget):
 
     def value_from_datadict(self, data, files, name):
         value = data.get(name)
-        if value:
+        if value is None:
+            return []
+        if value == "":
+            return []
+
+        if isinstance(value, list):
+            return [item for item in value if item is not None and str(item).strip()]
+
+        if isinstance(value, str):
+            if value.strip() == "" or value.strip().lower() == "null":
+                return []
             try:
                 parsed = json.loads(value)
-                if parsed:
+                if parsed is None:
+                    return []
+                if isinstance(parsed, list):
                     return [
                         item
                         for item in parsed
                         if item is not None and str(item).strip()
                     ]
-                return []
+                return [parsed] if str(parsed).strip() else []
             except (json.JSONDecodeError, TypeError):
-                pass
+                return [value] if value.strip() else []
+
         return []
 
 
@@ -104,11 +117,17 @@ class DynamicArrayField(forms.JSONField):
         if value is None:
             return []
         if isinstance(value, list):
-            return value
+            return [item for item in value if item is not None]
         if isinstance(value, str):
+            if value.strip() == "" or value.strip().lower() == "null":
+                return []
             try:
                 parsed = json.loads(value)
-                return parsed if isinstance(parsed, list) else [parsed]
+                if parsed is None:
+                    return []
+                if isinstance(parsed, list):
+                    return [item for item in parsed if item is not None]
+                return [parsed]
             except (json.JSONDecodeError, TypeError):
                 return [value] if value else []
         return [str(value)]
@@ -117,16 +136,24 @@ class DynamicArrayField(forms.JSONField):
         """Handle bound data properly to avoid JSON parsing issues"""
         if data is None:
             return initial
-        # If data is already a list (from our widget), return it as-is
         if isinstance(data, list):
-            return data
-        # If data is a string, try to parse it as JSON
+            return [item for item in data if item is not None and str(item).strip()]
         if isinstance(data, str):
+            if data.strip() == "" or data.strip().lower() == "null":
+                return []
             try:
                 parsed = json.loads(data)
-                return parsed if isinstance(parsed, list) else [parsed]
+                if parsed is None:
+                    return []
+                if isinstance(parsed, list):
+                    return [
+                        item
+                        for item in parsed
+                        if item is not None and str(item).strip()
+                    ]
+                return [parsed] if str(parsed).strip() else []
             except (json.JSONDecodeError, TypeError):
-                return [data] if data else []
+                return [data] if data and data.strip() else []
         return data
 
     def validate(self, value):
diff --git a/src/servala/static/js/dynamic-array.js b/src/servala/static/js/dynamic-array.js
index d038fdc..c198ddf 100644
--- a/src/servala/static/js/dynamic-array.js
+++ b/src/servala/static/js/dynamic-array.js
@@ -19,6 +19,9 @@ const initDynamicArrayWidget = () => {
         addRemoveEventListeners(container)
         addInputEventListeners(container)
         updateRemoveButtonVisibility(container)
+
+        // Ensure hidden input is synced with visible inputs on initialization
+        updateHiddenInput(container)
     })
 }
 
@@ -94,7 +97,7 @@ const updateHiddenInput = (container) => {
     if (!hiddenInput) return
 
     const values = Array.from(inputs)
-        .map(input => input.value.trim())
+        .map(input => input.value ? input.value.trim() : '')
         .filter(value => value !== '')
 
     hiddenInput.value = JSON.stringify(values)