Use IsValidJsonString, inplace of DetectIsJson - more reliable. (#567)

* Use IsValidJsonString, inplace of DetectIsJson - more reliable.

* Move to a TryParseValidJsonString, to reduce the number of times we parse the json.

uSync.Community.Contrib/Mappers/ContentmentContentBlocks.cs

@@ -7,8 +7,8 @@
 
 using Umbraco.Cms.Core.Models;
 using Umbraco.Cms.Core.Services;
-using Umbraco.Extensions;
 
+using uSync.Core;
 using uSync.Core.Dependency;
 using uSync.Core.Mapping;
 
@@ -55,10 +55,12 @@ protected override string ProcessValues(JToken jsonValue, string editorAlias, Fu
         public override IEnumerable<uSyncDependency> GetDependencies(object value, string editorAlias, DependencyFlags flags)
         {
             var stringValue = GetValueAs<string>(value);
-            if (string.IsNullOrWhiteSpace(stringValue) || !stringValue.DetectIsJson()) return Enumerable.Empty<uSyncDependency>();
 
-            var elements = JsonConvert.DeserializeObject<JArray>(stringValue);
-            if (elements == null || !elements.Any()) return Enumerable.Empty<uSyncDependency>();
+            if (stringValue.TryParseValidJsonString(out JArray elements) is false)
+                return Enumerable.Empty<uSyncDependency>();
+
+            if (elements == null || !elements.Any())
+                return Enumerable.Empty<uSyncDependency>();
 
             var dependencies = new List<uSyncDependency>();
 

uSync.Core/Extensions/JsonExtensions.cs

@@ -1,5 +1,6 @@
 
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.Net.Http.Headers;
 
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
@@ -111,6 +112,51 @@ private static JToken ExpandStringValue(string stringValue)
             return stringValue.GetJsonTokenValue();
         }
 
+        public static bool IsValidJsonString(this string value)
+        {
+            if (string.IsNullOrWhiteSpace(value) || !value.DetectIsJson())
+                return false; 
+
+            // umbraco thinks it's json, but is it ? 
+
+            try
+            {
+                JToken.Parse(value);
+                return true;
+            }
+            catch {
+                return false; 
+            }
+        }
+
+        public static bool TryParseValidJsonString(this string value, out JToken token)
+            => TryParseValidJsonString<JToken>(value, out token);
+
+        /// <summary>
+        ///  parse a value and return the JSON - only if it's valid JSON 
+        /// </summary>
+        /// <remarks>
+        ///  this value will return false for strings that don't look like json strings (e.g "hello" is false) 
+        /// </remarks>
+        public static bool TryParseValidJsonString<TResult>(this string value, out TResult result)
+            where TResult : JToken
+        {
+            result = default;
+            if (string.IsNullOrWhiteSpace(value) || !value.DetectIsJson())
+                return false;
+
+            try
+            {
+                result = JsonConvert.DeserializeObject<TResult>(value);
+                return true;
+            }
+            catch
+            {
+                return false; 
+            }
+        }
+
+
 
         public static JToken GetJTokenFromObject(this object value)
         {
@@ -140,4 +186,4 @@ public static TObject GetValueAs<TObject>(this object value)
         public static bool IsAngularExpression(this string value)
             => value.StartsWith("{{") && value.EndsWith("}}");
     }
-}
+}

uSync.Core/Mapping/Mappers/BlockListMapper.cs

@@ -8,7 +8,6 @@
 using Umbraco.Cms.Core;
 using Umbraco.Cms.Core.Models;
 using Umbraco.Cms.Core.Services;
-using Umbraco.Extensions;
 
 using uSync.Core.Dependency;
 
@@ -40,26 +39,21 @@ public BlockListMapper(IEntityService entityService,
         protected override JToken GetImportProperty(object value)
         {
             if (value == null) return null;
-
             var stringValue = value.GetValueAs<string>();
-            if (stringValue == null || !stringValue.DetectIsJson())
+
+            if (stringValue.TryParseValidJsonString(out JToken tokenValue) is false)
                 return stringValue;
 
             // we have to get the json, the serialize the json,
             // this is to make sure we don't serizlize any formatting
             // (like indented formatting). because that would 
             // register changes that are not there.
-            var b = JsonConvert.SerializeObject(value.GetJTokenFromObject(), Formatting.None);
-
-            return b;
+            return JsonConvert.SerializeObject(tokenValue, Formatting.None);
         }
 
 
         protected override JToken GetExportProperty(string value)
-        {
-            if (string.IsNullOrWhiteSpace(value) || !value.DetectIsJson()) return value;
-            return value.GetJsonTokenValue();
-        }
+            => value.TryParseValidJsonString(out JToken tokenValue) is true ? tokenValue : value;
 
         protected override string ProcessValues(JToken jsonValue, string editorAlias, Func<JObject, IContentType, JObject> GetPropertiesMethod)
         {

uSync.Core/Mapping/Mappers/ImagePathMapper.cs

@@ -74,30 +74,25 @@ public override string GetExportValue(object value, string editorAlias)
             var stringValue = value?.ToString();
             if (string.IsNullOrWhiteSpace(stringValue)) return stringValue;
 
-            if (stringValue.DetectIsJson())
+            if (stringValue.TryParseValidJsonString<JObject>(out JObject json) is false)
+                return StripSitePath(stringValue);
+
+            // json, 
+            if (json != null)
             {
-                // json, 
-                var json = JsonConvert.DeserializeObject<JObject>(stringValue);
-                if (json != null)
+                var source = json.Value<string>("src");
+                if (!string.IsNullOrWhiteSpace(source))
                 {
-                    var source = json.Value<string>("src");
-                    if (!string.IsNullOrWhiteSpace(source))
-                    {
-                        // strip any virtual directory stuff from it.
-                        json["src"] = StripSitePath(source);
-                        return JsonConvert.SerializeObject(json);
-                    }
+                    // strip any virtual directory stuff from it.
+                    json["src"] = StripSitePath(source);
+                    return JsonConvert.SerializeObject(json);
                 }
-
-                // we always reserialize if we can, because you can get inconsitancies, 
-                // and spaces in the json (especially from the starterkit)
-                // this just ensures it looks the same across sites (where possible).
-                return JsonConvert.SerializeObject(json, Formatting.Indented);
             }
 
-
-            // else .
-            return StripSitePath(stringValue);
+            // we always reserialize if we can, because you can get inconsitancies, 
+            // and spaces in the json (especially from the starterkit)
+            // this just ensures it looks the same across sites (where possible).
+            return JsonConvert.SerializeObject(json, Formatting.Indented);
         }
 
         private string StripSitePath(string filepath)
@@ -175,26 +170,17 @@ private string GetMediaFolderSetting(string umbracoMediaPath)
         public override string GetImportValue(string value, string editorAlias)
         {
             var stringValue = value?.ToString();
-            if (string.IsNullOrWhiteSpace(stringValue)) return stringValue;
+            if (string.IsNullOrWhiteSpace(stringValue) is true) return stringValue;
 
-            if (stringValue.DetectIsJson())
-            {
-                // json, 
-                var json = JsonConvert.DeserializeObject<JObject>(stringValue);
-                if (json != null)
-                {
-                    var source = json.Value<string>("src");
-                    if (!string.IsNullOrWhiteSpace(source))
-                    {
-                        // strip any virtual directory stuff from it.
-                        json["src"] = PrePendSitePath(source);
-                        return JsonConvert.SerializeObject(json);
-                    }
-                }
-            }
-            else
-            {
+            if (stringValue.TryParseValidJsonString(out JObject json) is false)
                 return PrePendSitePath(stringValue);
+
+            var source = json.Value<string>("src");
+            if (string.IsNullOrWhiteSpace(source) is false)
+            {
+                // strip any virtual directory stuff from it.
+                json["src"] = PrePendSitePath(source);
+                return JsonConvert.SerializeObject(json);
             }
 
             return stringValue;
@@ -228,15 +214,10 @@ public override IEnumerable<uSyncDependency> GetDependencies(object value, strin
 
         private string GetImagePath(string stringValue)
         {
-            if (stringValue.DetectIsJson())
+            if (stringValue.TryParseValidJsonString(out JObject json))
             {
-                // json, 
-                var json = JsonConvert.DeserializeObject<JObject>(stringValue);
-                if (json != null)
-                {
-                    var source = json.Value<string>("src");
-                    if (!string.IsNullOrWhiteSpace(source)) return source;
-                }
+                var source = json.Value<string>("src");
+                if (string.IsNullOrWhiteSpace(source) is false) return source;
             }
             else
             {

uSync.Core/Mapping/Mappers/MacroMapper.cs

@@ -61,10 +61,8 @@ public override IEnumerable<uSyncDependency> GetDependencies(object value, strin
 
         private MacroValue LoadMacroValue(string macroString)
         {
-            if (!macroString.DetectIsJson())
-            {
+            if (macroString.IsValidJsonString() is false)
                 return LoadFromMarkup(macroString);
-            }
 
             return JsonConvert.DeserializeObject<MacroValue>(macroString);
         }

uSync.Core/Mapping/Mappers/MediaPicker3Mapper.cs

@@ -30,9 +30,10 @@ public MediaPicker3Mapper(IEntityService entityService) : base(entityService)
         public override string GetExportValue(object value, string editorAlias)
         {
             var stringValue = value?.ToString();
-            if (string.IsNullOrEmpty(stringValue)) return null;
+            if (string.IsNullOrEmpty(stringValue) is true) return null;
 
-            if (!stringValue.DetectIsJson()) return stringValue;
+            if (stringValue.TryParseValidJsonString(out JArray json) is false)
+                return stringValue;
 
             // re-formatting the json in the picker.
             // 
@@ -45,29 +46,22 @@ public override string GetExportValue(object value, string editorAlias)
 
             try
             {
-                var json = JsonConvert.DeserializeObject<JArray>(value.ToString());
-                if (json != null)
-                    return JsonConvert.SerializeObject(json, Formatting.Indented);
+                return JsonConvert.SerializeObject(json, Formatting.Indented);
             }
             catch
             {
                 return stringValue;
             }
-
-            return stringValue;
-
         }
 
 
         public override IEnumerable<uSyncDependency> GetDependencies(object value, string editorAlias, DependencyFlags flags)
         {
             // validate string 
             var stringValue = value?.ToString();
-            if (string.IsNullOrWhiteSpace(stringValue) || !stringValue.DetectIsJson())
+            if (!stringValue.TryParseValidJsonString(out JArray images) is false)
                 return Enumerable.Empty<uSyncDependency>();
 
-            // convert to an array. 
-            var images = JsonConvert.DeserializeObject<JArray>(value.ToString());
             if (images == null || !images.Any())
                 return Enumerable.Empty<uSyncDependency>();
 

uSync.Core/Mapping/Mappers/NestedContentMapper.cs

@@ -55,10 +55,9 @@ protected override string ProcessValues(JToken jsonValue, string editorAlias, Fu
         public override IEnumerable<uSyncDependency> GetDependencies(object value, string editorAlias, DependencyFlags flags)
         {
             var stringValue = GetValueAs<string>(value);
-            if (string.IsNullOrWhiteSpace(stringValue) || !stringValue.DetectIsJson())
+            if (stringValue.TryParseValidJsonString(out JArray nestedJson) is false)
                 return Enumerable.Empty<uSyncDependency>();
 
-            var nestedJson = JsonConvert.DeserializeObject<JArray>(stringValue);
             if (nestedJson == null || !nestedJson.Any())
                 return Enumerable.Empty<uSyncDependency>();
 

uSync.Core/Mapping/Mappers/RepeatableValueMapper.cs

@@ -23,7 +23,7 @@ public RepeatableValueMapper(IEntityService entityService)
 
         public override string GetImportValue(string value, string editorAlias)
         {
-            if (value.DetectIsJson())
+            if (value.IsValidJsonString() is true)
             {
                 try
                 {

uSync.Core/Mapping/SyncValueMapperCollection.cs

@@ -88,11 +88,11 @@ public object GetImportValue(string value, string editorAlias)
         /// </summary>
         private string GetCleanFlatJson(string stringValue)
         {
-            if (string.IsNullOrWhiteSpace(stringValue) || !stringValue.DetectIsJson()) return stringValue;
-
+            if (stringValue.TryParseValidJsonString(out JToken result) is false) 
+                return stringValue;
             try
             {
-                return JsonConvert.SerializeObject(JsonConvert.DeserializeObject<JToken>(stringValue));
+                return JsonConvert.SerializeObject(result);
             }
             catch
             {

uSync.Core/Serialization/Serializers/ContentSerializerBase.cs

@@ -8,6 +8,7 @@
 using Microsoft.Extensions.Logging;
 
 using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
 
 using Umbraco.Cms.Core;
 using Umbraco.Cms.Core.Models;
@@ -660,9 +661,8 @@ protected string GetExportValue(object value, IPropertyType propertyType, string
             // TODO: in a perfect world, this is the best answer, don't escape any buried JSON in anything
             // but there might be a couple of property value converters that don't like their nested JSON
             // to not be escaped so we would need to do proper testing. 
-            if (exportValue.DetectIsJson() && !exportValue.IsAngularExpression())
+            if (exportValue.TryParseValidJsonString(out JToken tokenValue) is true)
             {
-                var tokenValue = exportValue.GetJsonTokenValue().ExpandAllJsonInToken();
                 return JsonConvert.SerializeObject(tokenValue, Formatting.Indented);
             }
             logger.LogTrace("Export Value {PropertyEditorAlias} {exportValue}", propertyType.PropertyEditorAlias, exportValue);

uSync.Core/Serialization/Serializers/MediaSerializer.cs

@@ -90,7 +90,8 @@ protected override SyncAttempt<IMedia> DeserializeCore(XElement node, SyncSerial
             }
 
             var saveAttempt = _mediaService.Save(item);
-            if (!saveAttempt.Success) {
+            if (!saveAttempt.Success)
+            {
                 var errors = saveAttempt.Result?.EventMessages?.FormatMessages() ?? "";
                 return SyncAttempt<IMedia>.Fail(item.Name, item, ChangeType.Fail, errors, saveAttempt.Exception);
             }
@@ -194,19 +195,17 @@ private XElement SerializeFileHash(IMedia item)
 
         private string GetFilePath(string value)
         {
-            if (value.DetectIsJson())
-            {
-                // image cropper.
-                var imageCrops = JsonConvert.DeserializeObject<ImageCropperValue>(value, new JsonSerializerSettings
-                {
-                    Culture = CultureInfo.InvariantCulture,
-                    FloatParseHandling = FloatParseHandling.Decimal
-                });
+            if (value.IsValidJsonString() is false)
+                return value;
 
-                return imageCrops.Src;
-            }
+            // image cropper.
+            var imageCrops = JsonConvert.DeserializeObject<ImageCropperValue>(value, new JsonSerializerSettings
+            {
+                Culture = CultureInfo.InvariantCulture,
+                FloatParseHandling = FloatParseHandling.Decimal
+            });
 
-            return value;
+            return imageCrops.Src;
         }
 
         protected override Attempt<IMedia> CreateItem(string alias, ITreeEntity parent, string itemType)

uSync.Core/Tracking/SyncXmlTracker.cs

@@ -290,7 +290,7 @@ private IEnumerable<uSyncChange> CompareNode(XElement target, XElement source, s
 
         private uSyncChange Compare(string target, string source, string path, string name, bool maskValue)
         {
-            if (source.DetectIsJson())
+            if (source.IsValidJsonString() is true)
             {
                 return JsonChange(target, source, path, name, maskValue);
             }