/// <summary>
/// Gets a delegate which determines if the property or field should not be serialized based upon its value.
/// </summary>
/// <param name="member"></param>
/// <returns>if has a value equivalent to the DefaultValueAttribute</returns>
/// <remarks>
/// This is useful for excluding serialization of default values.
/// </remarks>
public override ValueIgnoredDelegate GetValueIgnoredCallback(MemberInfo member)
{
Type objType = member.ReflectedType ?? member.DeclaringType;
JsonSpecifiedPropertyAttribute specifiedPropertyAttr = TypeCoercionUtility.GetAttribute <JsonSpecifiedPropertyAttribute>(member);
// look up specified property to see if exists
GetterDelegate specifiedPropertyGetter = null;
if (specifiedPropertyAttr != null && !String.IsNullOrEmpty(specifiedPropertyAttr.SpecifiedProperty))
{
PropertyInfo specProp = objType.GetProperty(specifiedPropertyAttr.SpecifiedProperty, BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
// ensure is correct return type
if (specProp != null && specProp.PropertyType == typeof(bool))
{
specifiedPropertyGetter = DynamicMethodGenerator.GetPropertyGetter(specProp);
}
}
DefaultValueAttribute defaultAttr = TypeCoercionUtility.GetAttribute <DefaultValueAttribute>(member);
if (defaultAttr == null)
{
if (specifiedPropertyGetter == null)
{
// no need to even create a delegate
return(null);
}
// create a delegate which simply calls the specified property
return(delegate(object target, object value)
{
return Object.Equals(false, specifiedPropertyGetter(target));
});
}
// extract default value since cannot change (is constant in attribute)
object defaultValue = defaultAttr.Value;
if (specifiedPropertyGetter == null)
{
// create a specific delegate which only has to compare the default value to the current value
return(delegate(object target, object value)
{
return Object.Equals(defaultValue, value);
});
}
// create a combined delegate which checks both states
return(delegate(object target, object value)
{
return
Object.Equals(defaultValue, value) ||
Object.Equals(false, specifiedPropertyGetter(target));
});
}
public static string GetJsonSpecifiedProperty(MemberInfo memberInfo)
{
if (memberInfo == null || !Attribute.IsDefined(memberInfo, typeof(JsonSpecifiedPropertyAttribute)))
{
return(null);
}
JsonSpecifiedPropertyAttribute jsonSpecifiedPropertyAttribute = (JsonSpecifiedPropertyAttribute)Attribute.GetCustomAttribute(memberInfo, typeof(JsonSpecifiedPropertyAttribute));
return(jsonSpecifiedPropertyAttribute.SpecifiedProperty);
}
/// <summary>
/// Determines if the property or field should not be serialized.
/// </summary>
/// <param name="objType"></param>
/// <param name="member"></param>
/// <param name="value"></param>
/// <returns></returns>
/// <remarks>
/// Checks these in order, if any returns true then this is true:
/// - is flagged with the JsonIgnoreAttribute property
/// - has a JsonSpecifiedProperty which returns false
/// </remarks>
private bool IsIgnored(Type objType, MemberInfo member, object obj)
{
if (JsonIgnoreAttribute.IsJsonIgnore(member))
{
return(true);
}
string specifiedProperty = JsonSpecifiedPropertyAttribute.GetJsonSpecifiedProperty(member);
if (!String.IsNullOrEmpty(specifiedProperty))
{
PropertyInfo specProp = objType.GetProperty(specifiedProperty);
if (specProp != null)
{
object isSpecified = specProp.GetValue(obj, null);
if (isSpecified is Boolean && !Convert.ToBoolean(isSpecified))
{
return(true);
}
}
}
if (this.settings.UseXmlSerializationAttributes)
{
if (JsonIgnoreAttribute.IsXmlIgnore(member))
{
return(true);
}
PropertyInfo specProp = objType.GetProperty(member.Name + "Specified");
if (specProp != null)
{
object isSpecified = specProp.GetValue(obj, null);
if (isSpecified is Boolean && !Convert.ToBoolean(isSpecified))
{
return(true);
}
}
}
return(false);
}
private bool IsIgnored(Type objType, MemberInfo member, object obj)
{
if (JsonIgnoreAttribute.IsJsonIgnore(member))
{
return(true);
}
var jsonSpecifiedProperty = JsonSpecifiedPropertyAttribute.GetJsonSpecifiedProperty(member);
if (!string.IsNullOrEmpty(jsonSpecifiedProperty))
{
PropertyInfo property = objType.GetProperty(jsonSpecifiedProperty);
if (property != null)
{
object value = property.GetValue(obj, null);
if (value is bool && !Convert.ToBoolean(value))
{
return(true);
}
}
}
if (Settings.UseXmlSerializationAttributes)
{
if (JsonIgnoreAttribute.IsXmlIgnore(member))
{
return(true);
}
PropertyInfo property2 = objType.GetProperty(member.Name + "Specified");
if (property2 != null)
{
object value2 = property2.GetValue(obj, null);
if (value2 is bool && !Convert.ToBoolean(value2))
{
return(true);
}
}
}
return(false);
}
