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Commit 7b01416

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author
Chris Santero
committed
ensure materialized updates create empty collection property values
This was causing null reference exceptions when materializing new objects of types that have to-many relationships.
1 parent 9fbe305 commit 7b01416

3 files changed

Lines changed: 59 additions & 56 deletions

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‎JSONAPI.EntityFramework/EntityFrameworkMaterializer.cs‎

Lines changed: 9 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -104,6 +104,7 @@ public virtual async Task<object> MaterializeAsync(Type type, object ephemeral)
104104
{
105105
// Didn't find it...create a new one!
106106
retval = Activator.CreateInstance(type);
107+
107108
DbContext.Set(type).Add(retval);
108109
if (!anyNull)
109110
{
@@ -331,6 +332,12 @@ private async Task Merge (Type type, object ephemeral, object material)
331332
Type elementType = GetSingleType(prop.PropertyType);
332333

333334
var materialMany = (IEnumerable<Object>)prop.GetValue(material, null);
335+
if (materialMany == null)
336+
{
337+
materialMany = prop.PropertyType.CreateEnumerableInstance();
338+
prop.SetValue(material, materialMany);
339+
}
340+
334341
var ephemeralMany = (IEnumerable<Object>)prop.GetValue(ephemeral, null);
335342

336343
var materialKeys = new HashSet<EntityKey>();
@@ -389,7 +396,8 @@ private async Task Merge (Type type, object ephemeral, object material)
389396
else
390397
{
391398
object[] idParams = ephemeralKey.EntityKeyValues.Select(ekv => ekv.Value).ToArray();
392-
prop.SetValue(material, await GetByIdAsync(prop.PropertyType, idParams), null);
399+
var relatedMaterial = await GetByIdAsync(prop.PropertyType, idParams);
400+
prop.SetValue(material, relatedMaterial, null);
393401
}
394402
}
395403
}

‎JSONAPI/Extensions/TypeExtensions.cs‎

Lines changed: 41 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,6 @@
11
using System;
2+
using System.Collections.Generic;
3+
using Newtonsoft.Json;
24

35
namespace JSONAPI.Extensions
46
{
@@ -18,5 +20,44 @@ public static bool CanWriteAsJsonApiAttribute(this Type objectType)
1820
|| objectType.IsEnum;
1921
}
2022

23+
public static IEnumerable<object> CreateEnumerableInstance(this Type type)
24+
{
25+
Type relType;
26+
if (type.IsGenericType)
27+
{
28+
relType = type.GetGenericArguments()[0];
29+
}
30+
else
31+
{
32+
// Must be an array at this point, right??
33+
relType = type.GetElementType();
34+
}
35+
36+
// Hmm...now we have to create an object that fits this property. This could get messy...
37+
if (!type.IsInterface && !type.IsAbstract)
38+
{
39+
// Whew...okay, just instantiate one of these...
40+
return (IEnumerable<Object>)Activator.CreateInstance(type);
41+
}
42+
43+
// Ugh...now we're really in trouble...hopefully one of these will work:
44+
if (type.IsGenericType)
45+
{
46+
if (type.IsAssignableFrom(typeof(List<>).MakeGenericType(relType)))
47+
{
48+
return (IEnumerable<Object>) Activator.CreateInstance(typeof(List<>).MakeGenericType(relType));
49+
}
50+
51+
if (type.IsAssignableFrom(typeof(HashSet<>).MakeGenericType(relType)))
52+
{
53+
return
54+
(IEnumerable<Object>) Activator.CreateInstance(typeof(HashSet<>).MakeGenericType(relType));
55+
}
56+
57+
//TODO: Other likely candidates??
58+
}
59+
60+
return null;
61+
}
2162
}
2263
}

‎JSONAPI/Json/JsonApiFormatter.cs‎

Lines changed: 9 additions & 55 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,5 @@
1-
using JSONAPI.Attributes;
1+
using System.Collections.ObjectModel;
2+
using JSONAPI.Attributes;
23
using JSONAPI.Core;
34
using Newtonsoft.Json;
45
using Newtonsoft.Json.Linq;
@@ -902,63 +903,16 @@ private void DeserializeLinkedResources(object obj, JsonReader reader)
902903
{
903904
// To-many relationship
904905

905-
Type relType;
906-
if (prop.PropertyType.IsGenericType)
907-
{
908-
relType = prop.PropertyType.GetGenericArguments()[0];
909-
}
910-
else
911-
{
912-
// Must be an array at this point, right??
913-
relType = prop.PropertyType.GetElementType();
914-
}
915-
916906
var hmrel = (IEnumerable<Object>) prop.GetValue(obj, null);
917907
if (hmrel == null)
918908
{
919-
// Hmm...now we have to create an object that fits this property. This could get messy...
920-
if (!prop.PropertyType.IsInterface && !prop.PropertyType.IsAbstract)
921-
{
922-
// Whew...okay, just instantiate one of these...
923-
hmrel = (IEnumerable<Object>) Activator.CreateInstance(prop.PropertyType);
924-
}
925-
else
926-
{
927-
// Ugh...now we're really in trouble...hopefully one of these will work:
928-
if (prop.PropertyType.IsGenericType)
929-
{
930-
if (prop.PropertyType.IsAssignableFrom(typeof (List<>).MakeGenericType(relType)))
931-
{
932-
hmrel =
933-
(IEnumerable<Object>)
934-
Activator.CreateInstance(typeof (List<>).MakeGenericType(relType));
935-
}
936-
else if (
937-
prop.PropertyType.IsAssignableFrom(
938-
typeof (HashSet<>).MakeGenericType(relType)))
939-
{
940-
hmrel =
941-
(IEnumerable<Object>)
942-
Activator.CreateInstance(
943-
typeof (HashSet<>).MakeGenericType(relType));
944-
}
945-
//TODO: Other likely candidates??
946-
else
947-
{
948-
// punt!
949-
throw new JsonReaderException(
950-
String.Format(
951-
"Could not create empty container for relationship property {0}!",
952-
prop));
953-
}
954-
}
955-
else
956-
{
957-
// erm...Array??!?
958-
hmrel =
959-
(IEnumerable<Object>) Array.CreateInstance(relType, linkageObjects.Count);
960-
}
961-
}
909+
hmrel = prop.PropertyType.CreateEnumerableInstance();
910+
if (hmrel == null)
911+
// punt!
912+
throw new JsonReaderException(
913+
String.Format(
914+
"Could not create empty container for relationship property {0}!",
915+
prop));
962916
}
963917

964918
// We're having problems with how to generalize/cast/generic-ize this code, so for the time

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