https://github.com/ricosuter/namotion.reflection
.NET library with advanced reflection APIs.
https://github.com/ricosuter/namotion.reflection
Last synced: 5 months ago
JSON representation
.NET library with advanced reflection APIs.
- Host: GitHub
- URL: https://github.com/ricosuter/namotion.reflection
- Owner: RicoSuter
- License: mit
- Created: 2019-03-31T17:03:59.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2025-03-07T16:37:05.000Z (7 months ago)
- Last Synced: 2025-04-14T23:16:27.677Z (6 months ago)
- Language: C#
- Homepage:
- Size: 448 KB
- Stars: 222
- Watchers: 4
- Forks: 46
- Open Issues: 29
-
Metadata Files:
- Readme: README.md
- License: LICENSE.md
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README
# Namotion.Reflection
[Storage](https://github.com/RicoSuter/Namotion.Storage) | [Messaging](https://github.com/RicoSuter/Namotion.Messaging) | Reflection
[](https://dev.azure.com/rsuter/Namotion/_build?definitionId=16)
[](https://dev.azure.com/rsuter/Namotion/_build?definitionId=16)
[](https://apimundo.com/organizations/nuget-org/nuget-feeds/public/packages/Namotion.Reflection/versions/latest)
[](https://discord.gg/BxQNy25WF6)
.NET library with advanced reflection APIs like XML documentation reading, Nullable Reference Types (C# 8) reflection and string based type checks.
This library is mainly used in [NJsonSchema](https://github.com/RicoSuter/NJsonSchema) and [NSwag](https://github.com/RicoSuter/NSwag).
## Contextual and cached types
Inheritance hierarchy:
- **CachedType:** A cached `Type` object which does not have a context
- **ContextualType:** A cached `Type` with contextual attributes (e.g. property attributes)
- **ContextualParameterInfo**
- **ContextualMemberInfo**
- **ContextualMethodInfo**
- **ContextualAccessorInfo**
- **ContextualPropertyInfo**
- **ContextualFieldInfo**
Behavior:
- Each `CachedType` instance is cached per `Type`, `ParameterInfo` or `MemberInfo`.
- Contextual and type attributes are evaluated only once and then cached for higher performance.
- If the original `Type` is `Nullable` then `T` is unwrapped and stored in the `Type` property - the original type can be accessed with the `OriginalType` property.
### Nullability reflection (C# 8)
With the `ContextualType` class you can reflect on the nullability of properties, fields, method parameters and return types which will be available when compiling with the C# 8 compiler with the Nullable Reference Types feature enabled.
Given the following test class with some C# 8 nullability annotations (?):
```csharp
#nullable enable
public class MyClass
{
public void MyMethod(Dictionary dictionary)
{
}
}
```
To reflect on the first parameter's nullability, we can load a `ContextualType` instance and display the nullability of the parameter's types:
```csharp
using Namotion.Reflection;
var method = typeof(MyClass).GetMethod(nameof(MyClass.MyMethod));
var parameter = method.GetParameters().First();
var contextualParameter = parameter.ToContextualParameter();
Console.WriteLine("Dictionary: " + contextualParameter.Nullability);
Console.WriteLine("Key: " + contextualParameter.GenericArguments[0].Nullability);
Console.WriteLine("Value: " + contextualParameter.GenericArguments[1].Nullability);
```
The output is:
```
Dictionary: NotNullable
Key: NotNullable
Value: Nullable
```
For more details, see https://blog.rsuter.com/the-output-of-nullable-reference-types-and-how-to-reflect-it/
Methods:
- CachedType.ClearCache()
### Validate nullability (C# 8)
It is important to understand that Nullable Reference Types is a compiler feature only and the .NET runtime does not do any checks when your app is running. Consider the following class:
```csharp
public class Person
{
public string FirstName { get; set; }
public string? MiddleName { get; set; }
public string LastName { get; set; }
}
```
Inside your application you'll get warnings when you forget to set the `FirstName`. However when data is coming from outside (e.g. via reflection, serialization, etc.) you could end up with invalid objects. This JSON.NET call throws no exception but will create an invalid object:
```csharp
var person = JsonConvert.DeserializeObject("{}");
```
Call the `EnsureValidNullability()` extension method which throws an `InvalidOperationException` when the object is in an invalid state:
```csharp
person.EnsureValidNullability();
```
Methods:
- HasValidNullability();
- EnsureValidNullability();
- ValidateNullability();
## Read XML Documentation
Methods:
- **Type|MemberInfo.GetXmlDocsSummaryAsync():**
- **Type|MemberInfo.GetXmlDocsRemarksAsync():**
- **ParameterInfo.GetXmlDocsAsync():** Gets the parameter's description
- **ParameterInfo.GetXmlDocsElementAsync():** Gets the `XElement` of the given type
- ... and more
- **XmlDocs.ClearCache()**
This functionality can also be used with [Cecil](https://github.com/jbevain/cecil) types with the [Namotion.Reflection.Cecil](https://apimundo.com/organizations/nuget-org/nuget-feeds/public/packages/Namotion.Reflection.Cecil/versions/latest/) package.
## Extension methods
Methods:
**IEnumerable extensions**
- **GetAssignableToTypeName():** Gets all objects which are assignable to the given type name as string.
- **FirstAssignableToTypeNameOrDefault():** Tries to get the first object which is assignable to the given type name as string.
- **GetCommonBaseType():** Finds the first common base type of the given types.
**Object extensions**
- **HasProperty():** Determines whether the specified property name exists.
- **TryGetPropertyValue():** Returns the value of the given property or null if the property does not exist.
**Type extensions**
- **IsAssignableToTypeName()**
- **InheritsFromTypeName()**
- **GetEnumerableItemType()**
- **GetDisplayName():** Gets a human readable identifier for the type (eg. "DictionaryOfStringAndInt32").