Fix crash when null colors are passed (#218)

JObject throws when checking for a null or undefined value. Instead of throwing we check for this and do not include the value allow the application to continue.

Author: nickwinder

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "react-native-pspdfkit",
-  "version": "1.23.8",
+  "version": "1.23.9",
   "description": "A React Native module for the PSPDFKit library.",
   "keywords": [
     "react native",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "Catalog",
-  "version": "1.23.8",
+  "version": "1.23.9",
   "private": true,
   "scripts": {
     "start": "node node_modules/react-native/local-cli/cli.js start"

samples/Catalog/package.json

@@ -1,9 +1,11 @@
 using System.Collections.Generic;
+using Windows.UI;
 using Newtonsoft.Json.Linq;
 using PSPDFKit.Search;
 using PSPDFKitFoundation;
 using PSPDFKitFoundation.Search;
 using PSPDFKitNative;
+using ReactNative.UIManager;
 
 namespace ReactNativePSPDFKit
 {
@@ -131,5 +133,20 @@ private static JArray LibraryQueryReultToJson(LibraryQueryResult libraryQueryRes
 
             return pageNumbersJson;
         }
+
+        internal static Color? ParserColor(JObject jObject, string propertyName)
+        {
+            if (TryGetNotNullValue(jObject, propertyName, out var jsonHighlightColor))
+            {
+                return ColorHelpers.Parse(jsonHighlightColor.Value<uint>());
+            }
+
+            return null;
+        }
+
+        internal static bool TryGetNotNullValue(JObject jObject, string propertyName, out JToken value)
+        {
+            return jObject.TryGetValue(propertyName, out value) && value.Type != JTokenType.Null;
+        }
     }
 }

windows/ReactNativePSPDFKit/ReactNativePSPDFKit/JsonUtils.cs

@@ -63,22 +63,23 @@ public void SetHideNavigationBar(PDFViewPage view, bool hideNavigationBar)
         public async void SetCustomCss(PDFViewPage view, JObject styleJObject)
         {
             var colorString = string.Empty;
-            if (styleJObject.ContainsKey("highlightColor"))
+
+            var maybeHighlightColor = JsonUtils.ParserColor(styleJObject, "highlightColor");
+            if (maybeHighlightColor.HasValue)
             {
-                var highlightColor = ColorHelpers.Parse(styleJObject["highlightColor"].Value<uint>());
-                colorString += $"    --primary: {highlightColor.ToHexWithoutAlpha()};\r\n";
+                colorString += $"    --primary: {maybeHighlightColor.Value.ToHexWithoutAlpha()};\r\n";
             }
 
-            if (styleJObject.ContainsKey("primaryColor"))
+            var maybePrimaryColor = JsonUtils.ParserColor(styleJObject, "primaryColor");
+            if (maybePrimaryColor.HasValue)
             {
-                var primaryColor = ColorHelpers.Parse(styleJObject["primaryColor"].Value<uint>());
-                colorString += $"    --primary-dark-1: {primaryColor.ToHexWithoutAlpha()};\r\n";
+                colorString += $"    --primary-dark-1: {maybePrimaryColor.Value.ToHexWithoutAlpha()};\r\n";
             }
 
-            if (styleJObject.ContainsKey("primaryDarkColor"))
+            var maybePrimaryDarkColor = JsonUtils.ParserColor(styleJObject, "primaryDarkColor");
+            if (maybePrimaryDarkColor.HasValue)
             {
-                var primaryDarkColor = ColorHelpers.Parse(styleJObject["primaryDarkColor"].Value<uint>());
-                colorString += $"    --primary-dark-2: {primaryDarkColor.ToHexWithoutAlpha()};\r\n";
+                colorString += $"    --primary-dark-2: {maybePrimaryDarkColor.Value.ToHexWithoutAlpha()};\r\n";
             }
 
             if (colorString.Length > 0)