jellyfin/Emby.Server.Implementations/Services/StringMapTypeDeserializer.cs
2019-02-20 16:49:03 +01:00

127 lines
4.4 KiB
C#

using System;
using System.Collections.Generic;
using System.Reflection;
namespace Emby.Server.Implementations.Services
{
/// <summary>
/// Serializer cache of delegates required to create a type from a string map (e.g. for REST urls)
/// </summary>
public class StringMapTypeDeserializer
{
internal class PropertySerializerEntry
{
public PropertySerializerEntry(Action<object, object> propertySetFn, Func<string, object> propertyParseStringFn, Type propertyType)
{
PropertySetFn = propertySetFn;
PropertyParseStringFn = propertyParseStringFn;
PropertyType = PropertyType;
}
public Action<object, object> PropertySetFn { get; private set; }
public Func<string, object> PropertyParseStringFn { get; private set; }
public Type PropertyType { get; private set; }
}
private readonly Type type;
private readonly Dictionary<string, PropertySerializerEntry> propertySetterMap
= new Dictionary<string, PropertySerializerEntry>(StringComparer.OrdinalIgnoreCase);
public Func<string, object> GetParseFn(Type propertyType)
{
if (propertyType == typeof(string))
{
return s => s;
}
return _GetParseFn(propertyType);
}
private readonly Func<Type, object> _CreateInstanceFn;
private readonly Func<Type, Func<string, object>> _GetParseFn;
public StringMapTypeDeserializer(Func<Type, object> createInstanceFn, Func<Type, Func<string, object>> getParseFn, Type type)
{
_CreateInstanceFn = createInstanceFn;
_GetParseFn = getParseFn;
this.type = type;
foreach (var propertyInfo in RestPath.GetSerializableProperties(type))
{
var propertySetFn = TypeAccessor.GetSetPropertyMethod(type, propertyInfo);
var propertyType = propertyInfo.PropertyType;
var propertyParseStringFn = GetParseFn(propertyType);
var propertySerializer = new PropertySerializerEntry(propertySetFn, propertyParseStringFn, propertyType);
propertySetterMap[propertyInfo.Name] = propertySerializer;
}
}
public object PopulateFromMap(object instance, IDictionary<string, string> keyValuePairs)
{
PropertySerializerEntry propertySerializerEntry = null;
if (instance == null)
{
instance = _CreateInstanceFn(type);
}
foreach (var pair in keyValuePairs)
{
string propertyName = pair.Key;
string propertyTextValue = pair.Value;
if (string.IsNullOrEmpty(propertyTextValue)
|| !propertySetterMap.TryGetValue(propertyName, out propertySerializerEntry)
|| propertySerializerEntry.PropertySetFn == null)
{
continue;
}
if (propertySerializerEntry.PropertyType == typeof(bool))
{
//InputExtensions.cs#530 MVC Checkbox helper emits extra hidden input field, generating 2 values, first is the real value
propertyTextValue = LeftPart(propertyTextValue, ',');
}
var value = propertySerializerEntry.PropertyParseStringFn(propertyTextValue);
if (value == null)
{
continue;
}
propertySerializerEntry.PropertySetFn(instance, value);
}
return instance;
}
public static string LeftPart(string strVal, char needle)
{
if (strVal == null)
{
return null;
}
var pos = strVal.IndexOf(needle);
return pos == -1
? strVal
: strVal.Substring(0, pos);
}
}
internal class TypeAccessor
{
public static Action<object, object> GetSetPropertyMethod(Type type, PropertyInfo propertyInfo)
{
if (!propertyInfo.CanWrite || propertyInfo.GetIndexParameters().Length > 0)
{
return null;
}
var setMethodInfo = propertyInfo.SetMethod;
return (instance, value) => setMethodInfo.Invoke(instance, new[] { value });
}
}
}