protected static void ParseDictionary(IDictionary<string, object> Dict, out object Target, Type explicitType)
I would say this method declaration is a big code smell. Having a void method with an out parameter just isn't right.
Why don't you let the method return an object ? There is just no reason.
Although it had been already mentioned by @akw5013 in his answer, based on the NET naming guidelines methodparameters should be named using camelCase casing.
If you choose a style for yourself, which is a valid decision, you should stick to this style. At this declaration you are mixing styles which is always a bad idea.
if (Dict.ContainsKey(propertyName) && Dict[propertyName] != null) { var val = Dict[propertyName]; var propertyVal = explicitType.GetProperty(propertyName);
This will be "incredible" slow. Internally this calls 3 times the FindEntry(key) method through the following methods
public bool ContainsKey(TKey key) {
return FindEntry(key) >= 0;
}
public TValue this[TKey key] {
get {
int i = FindEntry(key);
if (i >= 0) return entries[i].value;
ThrowHelper.ThrowKeyNotFoundException();
return default(TValue);
}
set {
Insert(key, value, false);
}
}
if you would use Dictionary.TryGetValue() this would result in only one call to
public bool TryGetValue(TKey key, out TValue value) {
int i = FindEntry(key);
if (i >= 0) {
value = entries[i].value;
return true;
}
value = default(TValue);
return false;
}
but fortunately this problem is easy to fix like so
object val;
var propertyName = property.Name;
if (Dict.TryGetValue(propertyName, out val) && val != null)
{
var propertyVal = explicitType.GetProperty(propertyName);
that had been easy, hadn't it ?
if(valType == expectedType) { //Hurray, we matched! propertyVal.SetValue(Target, val); } else if (valType != expectedType && val is IConvertible)
if the execution comes to the else if there is a 100% chance that valType != expectedType will be true.
else if (valType != expectedType && val is IConvertible) { Type safeType = Nullable.GetUnderlyingType(expectedType) ?? expectedType; //Special Case - INT64 to DATETIME Conversion (UNIX Time) if ((valType == typeof(long) || valType == typeof(long?)) && (safeType == typeof(DateTime) || safeType == typeof(DateTime?))) { var longValue = (long)Convert.ChangeType(val, typeof(long)); var dateValue = UNIX_EPOCH.AddSeconds(longValue); val = dateValue; } //Convert if possible var explicitVal = (val == null ? null : Convert.ChangeType(val, safeType)); propertyVal.SetValue(Target, explicitVal, null); }
the use of dateValue can just be skipped. Assigning the return value of UNIX_EPOCH.AddSeconds() to val is enough.
The tenary expression would IMO be better just an if..else like so
if (val == null)
{
propertyVal.SetValue(Target, null, null);
}
else
{
propertyVal.SetValue(Target, Convert.ChangeType(val, safeType), null);
}
else if (val is IDictionary<string, object>) { //Parse non-simple object var propType = propertyVal.PropertyType; object explicitVal = Activator.CreateInstance(propType); ParseDictionary(val as IDictionary<string, object>, out explicitVal, propType); propertyVal.SetValue(Target, explicitVal); }
Here you are creating an instance of propType which is overwritten inside the recursively called ParseDictionary() method. Just skip it.
var listType = typeof(List<>); var typedList = listType.MakeGenericType(elementType);
the var listType is only used once at the next line of code. You can compact this like so
var typedList = typeof(List<>).MakeGenericType(elementType);
and if you want you can just keep your pattern of typeType so typedList will become listType.
The creation of the List of this else if branch should be extracted to a separate method like so
private static IList ParseAsList(object val, Type expectedType, PropertyInfo property)
{
Type elementType = null;
if (expectedType.IsArray) //Array type is explicitly included with GetElementType
{
elementType = expectedType.GetElementType();
}
else if (expectedType.IsGenericType) //Get List type by inspecting generic argument
{
elementType = expectedType.GetGenericArguments()[0];
}
var listType = typeof(List<>).MakeGenericType(elementType);
var explicitList = (IList)Activator.CreateInstance(listType);
foreach (var element in val as IList<object>)
{
object explicitElement = ParseDictionary(element as IDictionary<string, object>, elementType);
explicitList.Add(explicitElement);
}
return explicitList;
}
which results in the branch beeing
else if (val is IList)
{
//Parse list/enumeration/array
if (!(expectedType.IsArray || expectedType.IsGenericType)
{
//Not sure how we'd get here if we're neither an array nor generic, but we can't really do much
continue;
}
//Create the necessary List implementation that we need
var explicitList = ParseAsList(val, expectedType, property);
if (expectedType.IsArray)
{
//Convert from list to array if necessary
var arrayType = expectedType.GetElementType().MakeArrayType();
var array = (Array)Activator.CreateInstance(arrayType, new object[] { explicitList.Count });
explicitList.CopyTo(array, 0);
propertyVal.SetValue(Target, array);
}
else
{
propertyVal.SetValue(Target, explicitList);
}
}
I couldn't come up with a better name than ParseAsList() so its just that.
The former ParseDictionary() method will now look like so
protected static object ParseDictionary(IDictionary<string, object> dict, Type explicitType)
{
if (dict == null)
{
throw new ArgumentNullException("dict", "Dictionary was null, cannot parse a null dictionary");
}
object target;
if (explicitType.IsArray)
{
var length = dict.Keys.Count();
target = (Array)Activator.CreateInstance(explicitType, new object[] { length });
}
else
{
target = Activator.CreateInstance(explicitType);
}
foreach (var property in target.GetType().GetProperties())
{
var propertyName = property.Name;
object val;
if (dict.TryGetValue(propertyName, out val) && val != null)
{
var propertyVal = explicitType.GetProperty(propertyName);
var expectedType = property.PropertyType;
var valType = val.GetType();
if (valType == expectedType)
{
propertyVal.SetValue(target, val);
}
else if (val is IConvertible)
{
Type safeType = Nullable.GetUnderlyingType(expectedType) ?? expectedType;
//Special Case - INT64 to DATETIME Conversion (UNIX Time)
if ((valType == typeof(long) || valType == typeof(long?))
&& (safeType == typeof(DateTime) || safeType == typeof(DateTime?)))
{
var longValue = (long)Convert.ChangeType(val, typeof(long));
val = UNIX_EPOCH.AddSeconds(longValue);
}
if (val == null)
{
propertyVal.SetValue(target, null, null);
}
else
{
propertyVal.SetValue(target, Convert.ChangeType(val, safeType), null);
}
}
else if (val is IDictionary<string, object>)
{
//Parse non-simple object
var propType = propertyVal.PropertyType;
object explicitVal = ParseDictionary(val as IDictionary<string, object>, propType);
propertyVal.SetValue(target, explicitVal);
}
else if (val is IList)
{
//Parse list/enumeration/array
if (!(expectedType.IsArray || expectedType.IsGenericType))
{
//Not sure how we'd get here if we're neither an array nor generic, but we can't really do much
continue;
}
//Create the necessary List implementation that we need
var explicitList = ParseAsList(val, expectedType, property);
if (expectedType.IsArray)
{
//Convert from list to array if necessary
var arrayType = expectedType.GetElementType().MakeArrayType();
var array = (Array)Activator.CreateInstance(arrayType, new object[] { explicitList.Count });
explicitList.CopyTo(array, 0);
propertyVal.SetValue(target, array);
}
else
{
propertyVal.SetValue(target, explicitList);
}
}
else
{
//Attempt to set it - will error if not compatible and all other checks are bypassed
propertyVal.SetValue(target, val);
}
}
}
return target;
}
As you can see I have added some vertical space (new lines) to structure the code a little bit better which makes it more readable too.
