diff options
Diffstat (limited to 'ApartmentManager/HousingWebApi/Areas/HelpPage/SampleGeneration/ObjectGenerator.cs')
| -rw-r--r-- | ApartmentManager/HousingWebApi/Areas/HelpPage/SampleGeneration/ObjectGenerator.cs | 456 |
1 files changed, 456 insertions, 0 deletions
diff --git a/ApartmentManager/HousingWebApi/Areas/HelpPage/SampleGeneration/ObjectGenerator.cs b/ApartmentManager/HousingWebApi/Areas/HelpPage/SampleGeneration/ObjectGenerator.cs new file mode 100644 index 0000000..9a34023 --- /dev/null +++ b/ApartmentManager/HousingWebApi/Areas/HelpPage/SampleGeneration/ObjectGenerator.cs @@ -0,0 +1,456 @@ +using System; +using System.Collections; +using System.Collections.Generic; +using System.Diagnostics.CodeAnalysis; +using System.Globalization; +using System.Linq; +using System.Reflection; + +namespace HousingWebApi.Areas.HelpPage +{ + /// <summary> + /// This class will create an object of a given type and populate it with sample data. + /// </summary> + public class ObjectGenerator + { + internal const int DefaultCollectionSize = 2; + private readonly SimpleTypeObjectGenerator SimpleObjectGenerator = new SimpleTypeObjectGenerator(); + + /// <summary> + /// Generates an object for a given type. The type needs to be public, have a public default constructor and settable public properties/fields. Currently it supports the following types: + /// Simple types: <see cref="int"/>, <see cref="string"/>, <see cref="Enum"/>, <see cref="DateTime"/>, <see cref="Uri"/>, etc. + /// Complex types: POCO types. + /// Nullables: <see cref="Nullable{T}"/>. + /// Arrays: arrays of simple types or complex types. + /// Key value pairs: <see cref="KeyValuePair{TKey,TValue}"/> + /// Tuples: <see cref="Tuple{T1}"/>, <see cref="Tuple{T1,T2}"/>, etc + /// Dictionaries: <see cref="IDictionary{TKey,TValue}"/> or anything deriving from <see cref="IDictionary{TKey,TValue}"/>. + /// Collections: <see cref="IList{T}"/>, <see cref="IEnumerable{T}"/>, <see cref="ICollection{T}"/>, <see cref="IList"/>, <see cref="IEnumerable"/>, <see cref="ICollection"/> or anything deriving from <see cref="ICollection{T}"/> or <see cref="IList"/>. + /// Queryables: <see cref="IQueryable"/>, <see cref="IQueryable{T}"/>. + /// </summary> + /// <param name="type">The type.</param> + /// <returns>An object of the given type.</returns> + public object GenerateObject(Type type) + { + return GenerateObject(type, new Dictionary<Type, object>()); + } + + [SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "Here we just want to return null if anything goes wrong.")] + private object GenerateObject(Type type, Dictionary<Type, object> createdObjectReferences) + { + try + { + if (SimpleTypeObjectGenerator.CanGenerateObject(type)) + { + return SimpleObjectGenerator.GenerateObject(type); + } + + if (type.IsArray) + { + return GenerateArray(type, DefaultCollectionSize, createdObjectReferences); + } + + if (type.IsGenericType) + { + return GenerateGenericType(type, DefaultCollectionSize, createdObjectReferences); + } + + if (type == typeof(IDictionary)) + { + return GenerateDictionary(typeof(Hashtable), DefaultCollectionSize, createdObjectReferences); + } + + if (typeof(IDictionary).IsAssignableFrom(type)) + { + return GenerateDictionary(type, DefaultCollectionSize, createdObjectReferences); + } + + if (type == typeof(IList) || + type == typeof(IEnumerable) || + type == typeof(ICollection)) + { + return GenerateCollection(typeof(ArrayList), DefaultCollectionSize, createdObjectReferences); + } + + if (typeof(IList).IsAssignableFrom(type)) + { + return GenerateCollection(type, DefaultCollectionSize, createdObjectReferences); + } + + if (type == typeof(IQueryable)) + { + return GenerateQueryable(type, DefaultCollectionSize, createdObjectReferences); + } + + if (type.IsEnum) + { + return GenerateEnum(type); + } + + if (type.IsPublic || type.IsNestedPublic) + { + return GenerateComplexObject(type, createdObjectReferences); + } + } + catch + { + // Returns null if anything fails + return null; + } + + return null; + } + + private static object GenerateGenericType(Type type, int collectionSize, Dictionary<Type, object> createdObjectReferences) + { + Type genericTypeDefinition = type.GetGenericTypeDefinition(); + if (genericTypeDefinition == typeof(Nullable<>)) + { + return GenerateNullable(type, createdObjectReferences); + } + + if (genericTypeDefinition == typeof(KeyValuePair<,>)) + { + return GenerateKeyValuePair(type, createdObjectReferences); + } + + if (IsTuple(genericTypeDefinition)) + { + return GenerateTuple(type, createdObjectReferences); + } + + Type[] genericArguments = type.GetGenericArguments(); + if (genericArguments.Length == 1) + { + if (genericTypeDefinition == typeof(IList<>) || + genericTypeDefinition == typeof(IEnumerable<>) || + genericTypeDefinition == typeof(ICollection<>)) + { + Type collectionType = typeof(List<>).MakeGenericType(genericArguments); + return GenerateCollection(collectionType, collectionSize, createdObjectReferences); + } + + if (genericTypeDefinition == typeof(IQueryable<>)) + { + return GenerateQueryable(type, collectionSize, createdObjectReferences); + } + + Type closedCollectionType = typeof(ICollection<>).MakeGenericType(genericArguments[0]); + if (closedCollectionType.IsAssignableFrom(type)) + { + return GenerateCollection(type, collectionSize, createdObjectReferences); + } + } + + if (genericArguments.Length == 2) + { + if (genericTypeDefinition == typeof(IDictionary<,>)) + { + Type dictionaryType = typeof(Dictionary<,>).MakeGenericType(genericArguments); + return GenerateDictionary(dictionaryType, collectionSize, createdObjectReferences); + } + + Type closedDictionaryType = typeof(IDictionary<,>).MakeGenericType(genericArguments[0], genericArguments[1]); + if (closedDictionaryType.IsAssignableFrom(type)) + { + return GenerateDictionary(type, collectionSize, createdObjectReferences); + } + } + + if (type.IsPublic || type.IsNestedPublic) + { + return GenerateComplexObject(type, createdObjectReferences); + } + + return null; + } + + private static object GenerateTuple(Type type, Dictionary<Type, object> createdObjectReferences) + { + Type[] genericArgs = type.GetGenericArguments(); + object[] parameterValues = new object[genericArgs.Length]; + bool failedToCreateTuple = true; + ObjectGenerator objectGenerator = new ObjectGenerator(); + for (int i = 0; i < genericArgs.Length; i++) + { + parameterValues[i] = objectGenerator.GenerateObject(genericArgs[i], createdObjectReferences); + failedToCreateTuple &= parameterValues[i] == null; + } + if (failedToCreateTuple) + { + return null; + } + object result = Activator.CreateInstance(type, parameterValues); + return result; + } + + private static bool IsTuple(Type genericTypeDefinition) + { + return genericTypeDefinition == typeof(Tuple<>) || + genericTypeDefinition == typeof(Tuple<,>) || + genericTypeDefinition == typeof(Tuple<,,>) || + genericTypeDefinition == typeof(Tuple<,,,>) || + genericTypeDefinition == typeof(Tuple<,,,,>) || + genericTypeDefinition == typeof(Tuple<,,,,,>) || + genericTypeDefinition == typeof(Tuple<,,,,,,>) || + genericTypeDefinition == typeof(Tuple<,,,,,,,>); + } + + private static object GenerateKeyValuePair(Type keyValuePairType, Dictionary<Type, object> createdObjectReferences) + { + Type[] genericArgs = keyValuePairType.GetGenericArguments(); + Type typeK = genericArgs[0]; + Type typeV = genericArgs[1]; + ObjectGenerator objectGenerator = new ObjectGenerator(); + object keyObject = objectGenerator.GenerateObject(typeK, createdObjectReferences); + object valueObject = objectGenerator.GenerateObject(typeV, createdObjectReferences); + if (keyObject == null && valueObject == null) + { + // Failed to create key and values + return null; + } + object result = Activator.CreateInstance(keyValuePairType, keyObject, valueObject); + return result; + } + + private static object GenerateArray(Type arrayType, int size, Dictionary<Type, object> createdObjectReferences) + { + Type type = arrayType.GetElementType(); + Array result = Array.CreateInstance(type, size); + bool areAllElementsNull = true; + ObjectGenerator objectGenerator = new ObjectGenerator(); + for (int i = 0; i < size; i++) + { + object element = objectGenerator.GenerateObject(type, createdObjectReferences); + result.SetValue(element, i); + areAllElementsNull &= element == null; + } + + if (areAllElementsNull) + { + return null; + } + + return result; + } + + private static object GenerateDictionary(Type dictionaryType, int size, Dictionary<Type, object> createdObjectReferences) + { + Type typeK = typeof(object); + Type typeV = typeof(object); + if (dictionaryType.IsGenericType) + { + Type[] genericArgs = dictionaryType.GetGenericArguments(); + typeK = genericArgs[0]; + typeV = genericArgs[1]; + } + + object result = Activator.CreateInstance(dictionaryType); + MethodInfo addMethod = dictionaryType.GetMethod("Add") ?? dictionaryType.GetMethod("TryAdd"); + MethodInfo containsMethod = dictionaryType.GetMethod("Contains") ?? dictionaryType.GetMethod("ContainsKey"); + ObjectGenerator objectGenerator = new ObjectGenerator(); + for (int i = 0; i < size; i++) + { + object newKey = objectGenerator.GenerateObject(typeK, createdObjectReferences); + if (newKey == null) + { + // Cannot generate a valid key + return null; + } + + bool containsKey = (bool)containsMethod.Invoke(result, new object[] { newKey }); + if (!containsKey) + { + object newValue = objectGenerator.GenerateObject(typeV, createdObjectReferences); + addMethod.Invoke(result, new object[] { newKey, newValue }); + } + } + + return result; + } + + private static object GenerateEnum(Type enumType) + { + Array possibleValues = Enum.GetValues(enumType); + if (possibleValues.Length > 0) + { + return possibleValues.GetValue(0); + } + return null; + } + + private static object GenerateQueryable(Type queryableType, int size, Dictionary<Type, object> createdObjectReferences) + { + bool isGeneric = queryableType.IsGenericType; + object list; + if (isGeneric) + { + Type listType = typeof(List<>).MakeGenericType(queryableType.GetGenericArguments()); + list = GenerateCollection(listType, size, createdObjectReferences); + } + else + { + list = GenerateArray(typeof(object[]), size, createdObjectReferences); + } + if (list == null) + { + return null; + } + if (isGeneric) + { + Type argumentType = typeof(IEnumerable<>).MakeGenericType(queryableType.GetGenericArguments()); + MethodInfo asQueryableMethod = typeof(Queryable).GetMethod("AsQueryable", new[] { argumentType }); + return asQueryableMethod.Invoke(null, new[] { list }); + } + + return Queryable.AsQueryable((IEnumerable)list); + } + + private static object GenerateCollection(Type collectionType, int size, Dictionary<Type, object> createdObjectReferences) + { + Type type = collectionType.IsGenericType ? + collectionType.GetGenericArguments()[0] : + typeof(object); + object result = Activator.CreateInstance(collectionType); + MethodInfo addMethod = collectionType.GetMethod("Add"); + bool areAllElementsNull = true; + ObjectGenerator objectGenerator = new ObjectGenerator(); + for (int i = 0; i < size; i++) + { + object element = objectGenerator.GenerateObject(type, createdObjectReferences); + addMethod.Invoke(result, new object[] { element }); + areAllElementsNull &= element == null; + } + + if (areAllElementsNull) + { + return null; + } + + return result; + } + + private static object GenerateNullable(Type nullableType, Dictionary<Type, object> createdObjectReferences) + { + Type type = nullableType.GetGenericArguments()[0]; + ObjectGenerator objectGenerator = new ObjectGenerator(); + return objectGenerator.GenerateObject(type, createdObjectReferences); + } + + private static object GenerateComplexObject(Type type, Dictionary<Type, object> createdObjectReferences) + { + object result = null; + + if (createdObjectReferences.TryGetValue(type, out result)) + { + // The object has been created already, just return it. This will handle the circular reference case. + return result; + } + + if (type.IsValueType) + { + result = Activator.CreateInstance(type); + } + else + { + ConstructorInfo defaultCtor = type.GetConstructor(Type.EmptyTypes); + if (defaultCtor == null) + { + // Cannot instantiate the type because it doesn't have a default constructor + return null; + } + + result = defaultCtor.Invoke(new object[0]); + } + createdObjectReferences.Add(type, result); + SetPublicProperties(type, result, createdObjectReferences); + SetPublicFields(type, result, createdObjectReferences); + return result; + } + + private static void SetPublicProperties(Type type, object obj, Dictionary<Type, object> createdObjectReferences) + { + PropertyInfo[] properties = type.GetProperties(BindingFlags.Public | BindingFlags.Instance); + ObjectGenerator objectGenerator = new ObjectGenerator(); + foreach (PropertyInfo property in properties) + { + if (property.CanWrite) + { + object propertyValue = objectGenerator.GenerateObject(property.PropertyType, createdObjectReferences); + property.SetValue(obj, propertyValue, null); + } + } + } + + private static void SetPublicFields(Type type, object obj, Dictionary<Type, object> createdObjectReferences) + { + FieldInfo[] fields = type.GetFields(BindingFlags.Public | BindingFlags.Instance); + ObjectGenerator objectGenerator = new ObjectGenerator(); + foreach (FieldInfo field in fields) + { + object fieldValue = objectGenerator.GenerateObject(field.FieldType, createdObjectReferences); + field.SetValue(obj, fieldValue); + } + } + + private class SimpleTypeObjectGenerator + { + private long _index = 0; + private static readonly Dictionary<Type, Func<long, object>> DefaultGenerators = InitializeGenerators(); + + [SuppressMessage("Microsoft.Maintainability", "CA1502:AvoidExcessiveComplexity", Justification = "These are simple type factories and cannot be split up.")] + private static Dictionary<Type, Func<long, object>> InitializeGenerators() + { + return new Dictionary<Type, Func<long, object>> + { + { typeof(Boolean), index => true }, + { typeof(Byte), index => (Byte)64 }, + { typeof(Char), index => (Char)65 }, + { typeof(DateTime), index => DateTime.Now }, + { typeof(DateTimeOffset), index => new DateTimeOffset(DateTime.Now) }, + { typeof(DBNull), index => DBNull.Value }, + { typeof(Decimal), index => (Decimal)index }, + { typeof(Double), index => (Double)(index + 0.1) }, + { typeof(Guid), index => Guid.NewGuid() }, + { typeof(Int16), index => (Int16)(index % Int16.MaxValue) }, + { typeof(Int32), index => (Int32)(index % Int32.MaxValue) }, + { typeof(Int64), index => (Int64)index }, + { typeof(Object), index => new object() }, + { typeof(SByte), index => (SByte)64 }, + { typeof(Single), index => (Single)(index + 0.1) }, + { + typeof(String), index => + { + return String.Format(CultureInfo.CurrentCulture, "sample string {0}", index); + } + }, + { + typeof(TimeSpan), index => + { + return TimeSpan.FromTicks(1234567); + } + }, + { typeof(UInt16), index => (UInt16)(index % UInt16.MaxValue) }, + { typeof(UInt32), index => (UInt32)(index % UInt32.MaxValue) }, + { typeof(UInt64), index => (UInt64)index }, + { + typeof(Uri), index => + { + return new Uri(String.Format(CultureInfo.CurrentCulture, "http://webapihelppage{0}.com", index)); + } + }, + }; + } + + public static bool CanGenerateObject(Type type) + { + return DefaultGenerators.ContainsKey(type); + } + + public object GenerateObject(Type type) + { + return DefaultGenerators[type](++_index); + } + } + } +}
\ No newline at end of file |