Extensible object manager docs

docs/en/Best-Practices/Application-Services.md

@@ -17,17 +17,18 @@
 
 ##### Basic DTO
 
-**Do** define a **basic** DTO for an entity.
+**Do** define a **basic** DTO for an aggregate root.
 
-- Include all the **primitive properties** directly on the entity.
-  - Exception: Can **exclude** properties for **security** reasons (like User.Password).
+- Include all the **primitive properties** directly on the aggregate root.
+  - Exception: Can **exclude** properties for **security** reasons (like `User.Password`).
 - Include all the **sub collections** of the entity where every item in the collection is a simple **relation DTO**.
+- Inherit from one of the **extensible entity DTO** classes for aggregate roots (and entities implement the `IHasExtraProperties`).
 
 Example:
 
 ```c#
 [Serializable]
-public class IssueDto : FullAuditedEntityDto<Guid>
+public class IssueDto : ExtensibleFullAuditedEntityDto<Guid>
 {
     public string Title { get; set; }
     public string Text { get; set; }
@@ -57,7 +58,7 @@ Example:
 
 ````C#
 [Serializable]
-public class IssueWithDetailsDto : FullAuditedEntityDto<Guid>
+public class IssueWithDetailsDto : ExtensibleFullAuditedEntityDto<Guid>
 {
     public string Title { get; set; }
     public string Text { get; set; }
@@ -66,14 +67,14 @@ public class IssueWithDetailsDto : FullAuditedEntityDto<Guid>
 }
 
 [Serializable]
-public class MilestoneDto : EntityDto<Guid>
+public class MilestoneDto : ExtensibleEntityDto<Guid>
 {
     public string Name { get; set; }
     public bool IsClosed { get; set; }
 }
 
 [Serializable]
-public class LabelDto : EntityDto<Guid>
+public class LabelDto : ExtensibleEntityDto<Guid>
 {
     public string Name { get; set; }
     public string Color { get; set; }
@@ -120,6 +121,7 @@ Task<List<QuestionWithDetailsDto>> GetListAsync(QuestionListQueryDto queryDto);
 
 * **Do** use the `CreateAsync` **method name**.
 * **Do** get a **specialized input** DTO to create the entity.
+* **Do** inherit the DTO class from the `ExtensibleObject` (or any other class implements the `IHasExtraProperties`) to allow to pass extra properties if needed.
 * **Do** use **data annotations** for input validation.
   * Share constants between domain wherever possible (via constants defined in the **domain shared** package).
 * **Do** return **the detailed** DTO for new created entity.
@@ -135,10 +137,11 @@ The related **DTO**:
 
 ````C#
 [Serializable]
-public class CreateQuestionDto
+public class CreateQuestionDto : ExtensibleObject
 {
     [Required]
-    [StringLength(QuestionConsts.MaxTitleLength, MinimumLength = QuestionConsts.MinTitleLength)]
+    [StringLength(QuestionConsts.MaxTitleLength,
+                  MinimumLength = QuestionConsts.MinTitleLength)]
     public string Title { get; set; }
 
     [StringLength(QuestionConsts.MaxTextLength)]
@@ -152,6 +155,7 @@ public class CreateQuestionDto
 
 - **Do** use the `UpdateAsync` **method name**.
 - **Do** get a **specialized input** DTO to update the entity.
+- **Do** inherit the DTO class from the `ExtensibleObject` (or any other class implements the `IHasExtraProperties`) to allow to pass extra properties if needed.
 - **Do** get the Id of the entity as a separated primitive parameter. Do not include to the update DTO.
 - **Do** use **data annotations** for input validation.
   - Share constants between domain wherever possible (via constants defined in the **domain shared** package).
@@ -200,6 +204,10 @@ This method votes a question and returns the current score of the question.
 
 * **Do not** use LINQ/SQL for querying data from database inside the application service methods. It's repository's responsibility to perform LINQ/SQL queries from the data source.
 
+#### Extra Properties
+
+* **Do** use either `MapExtraPropertiesTo` extension method ([see](Object-Extensions.md)) or configure the object mapper (`MapExtraProperties`) to allow application developers to be able to extend the objects and services.
+
 #### Manipulating / Deleting Entities
 
 * **Do** always get all the related entities from repositories to perform the operations on them.

docs/en/Best-Practices/Data-Transfer-Objects.md

@@ -2,6 +2,7 @@
 
 * **Do** define DTOs in the **application contracts** package.
 * **Do** inherit from the pre-built **base DTO classes** where possible and necessary (like `EntityDto<TKey>`, `CreationAuditedEntityDto<TKey>`, `AuditedEntityDto<TKey>`, `FullAuditedEntityDto<TKey>` and so on).
+  * **Do** inherit from the **extensible DTO** classes for the **aggregate roots** (like `ExtensibleAuditedEntityDto<TKey>`), because aggregate roots are extensible objects and extra properties are mapped to DTOs in this way.
 * **Do** define DTO members with **public getter and setter**.
 * **Do** use **data annotations** for **validation** on the properties of DTOs those are inputs of the service.
 * **Do** not add any **logic** into DTOs except implementing `IValidatableObject` when necessary.

docs/en/Object-Extensions.md

@@ -1,3 +1,267 @@
 # Object Extensions
 
-TODO
+ABP Framework provides an **object extension system** to allow you to **add extra properties** to an existing object **without modifying** the related class. This allows to extend functionalities implemented by a depended [application module](Modules/Index.md), especially when you want to [extend entities](Customizing-Application-Modules-Extending-Entities.md) and [DTOs](Customizing-Application-Modules-Overriding-Services.md) defined by the module.
+
+> Object extension system is not normally not needed for your own objects since you can easily add regular properties to your own classes.
+
+## IHasExtraProperties Interface
+
+This is the interface to make a class extensible. It simply defines a `Dictionary` property:
+
+````csharp
+Dictionary<string, object> ExtraProperties { get; }
+````
+
+Then you can add or get extra properties using this dictionary.
+
+### Base Classes
+
+`IHasExtraProperties` interface is implemented by several base classes by default:
+
+* Implemented by the `AggregateRoot` class (see [entities](Entities.md)).
+* Implemented by `ExtensibleEntityDto`, `ExtensibleAuditedEntityDto`... base [DTO](Data-Transfer-Objects.md) classes.
+* Implemented by the `ExtensibleObject`, which is a simple base class can be inherited for any type of object.
+
+So, if you inherit from these classes, your class will also be extensible. If not, you can always implement it manually.
+
+### Fundamental Extension Methods
+
+While you can directly use the `ExtraProperties` property of a class, it is suggested to use the following extension methods while working with the extra properties.
+
+#### SetProperty
+
+Used to set the value of an extra property:
+
+````csharp
+user.SetProperty("Title", "My Title");
+user.SetProperty("IsSuperUser", true);
+````
+
+`SetProperty` returns the same object, so you can chain it:
+
+````csharp
+user.SetProperty("Title", "My Title")
+    .SetProperty("IsSuperUser", true);
+````
+
+#### GetProperty
+
+Used to read the value of an extra property:
+
+````csharp
+var title = user.GetProperty<string>("Title");
+
+if (user.GetProperty<bool>("IsSuperUser"))
+{
+    //...
+}
+````
+
+* `GetProperty` is a generic method and takes the object type as the generic parameter.
+* Returns the default value if given property was not set before (default value is `0` for `int`, `false` for `bool`... etc).
+
+##### Non Primitive Property Types
+
+If your property type is not a primitive (int, bool, enum, string... etc) type, then you need to use non-generic version of the `GetProperty` which returns an `object`.
+
+#### HasProperty
+
+Used to check if the object has a property set before.
+
+#### RemoveProperty
+
+Used to remove a property from the object. Use this methods instead of setting a `null` value for the property.
+
+### Some Best Practices
+
+Using magic strings for the property names is dangerous since you can easily type the property name wrong - it is not type safe. Instead;
+
+* Define a constant for your extra property names
+* Create extension methods to easily set your extra properties.
+
+Example:
+
+````csharp
+public static class IdentityUserExtensions
+{
+    private const string TitlePropertyName = "Title";
+
+    public static void SetTitle(this IdentityUser user, string title)
+    {
+        user.SetProperty(TitlePropertyName, title);
+    }
+
+    public static string GetTitle(this IdentityUser user)
+    {
+        return user.GetProperty<string>(TitlePropertyName);
+    }
+}
+````
+
+Then you can easily set or get the `Title` property:
+
+````csharp
+user.SetTitle("My Title");
+var title = user.GetTitle();
+````
+
+## Object Extension Manager
+
+While you can set arbitrary properties to an extensible object (which implements the `IHasExtraProperties` interface), `ObjectExtensionManager` is used to explicitly define extra properties for extensible classes.
+
+Explicitly defining an extra property has some use cases:
+
+* Allows to control how the extra property is handled on object to object mapping (see the section below).
+* Allows to define metadata for the property. For example, you can map an extra property to a table field in the database while using the [EF Core](Entity-Framework-Core.md).
+
+> `ObjectExtensionManager` implements the singleton pattern (`ObjectExtensionManager.Instance`) and you should define object extensions before your application startup. The [application startup template](Startup-Templates/Application.md) has some pre-defined static classes to safely define object extensions inside.
+
+### AddOrUpdate
+
+`AddOrUpdate` is the main method to define a extra properties or update extra properties for an object.
+
+Example: Define extra properties for the `IdentityUser` entity:
+
+````csharp
+ObjectExtensionManager.Instance
+    .AddOrUpdate<IdentityUser>(options =>
+        {
+            options.AddOrUpdateProperty<string>("SocialSecurityNumber");
+            options.AddOrUpdateProperty<bool>("IsSuperUser");
+        }
+    );
+````
+
+### AddOrUpdateProperty
+
+While `AddOrUpdateProperty` can be used on the `options` as shown before, if you want to define a single extra property, you can use the shortcut extension method too:
+
+````csharp
+ObjectExtensionManager.Instance
+    .AddOrUpdateProperty<IdentityUser, string>("SocialSecurityNumber");
+````
+
+Sometimes it would be practical to define a single extra property to multiple types. Instead of defining one by one, you can use the following code:
+
+````csharp
+ObjectExtensionManager.Instance
+    .AddOrUpdateProperty<string>(
+        new[]
+        {
+            typeof(IdentityUserDto),
+            typeof(IdentityUserCreateDto),
+            typeof(IdentityUserUpdateDto)
+        },
+        "SocialSecurityNumber"
+    );
+````
+
+#### Property Configuration
+
+`AddOrUpdateProperty` can also get an action that can perform additional configuration on the property definition.
+
+Example:
+
+````csharp
+ObjectExtensionManager.Instance
+    .AddOrUpdateProperty<IdentityUser, string>(
+        "SocialSecurityNumber",
+        options =>
+        {
+            options.CheckPairDefinitionOnMapping = false;
+        });
+````
+
+> See the "Object to Object Mapping" section to understand the `CheckPairDefinitionOnMapping` option.
+
+`options` has a dictionary, named `Configuration` which makes the object extension definitions even extensible. It is used by the EF Core to map extra properties to table fields in the database. See the [extending entities](Customizing-Application-Modules-Extending-Entities.md) document.
+
+## Object to Object Mapping
+
+Assume that you've added an extra property to an extensible entity object and used auto [object to object mapping](Object-To-Object-Mapping.md) to map this entity to an extensible DTO class. You need to be careful in such a case, because the extra property may contain a **sensitive data** that should not be available to clients.
+
+This section offers some **good practices** to control your extra properties on object mapping.
+
+### MapExtraPropertiesTo
+
+`MapExtraPropertiesTo` is an extension method provided by the ABP Framework to copy extra properties from an object to another in a controlled manner. Example usage:
+
+````csharp
+identityUser.MapExtraPropertiesTo(identityUserDto);
+````
+
+`MapExtraPropertiesTo` **requires to define properties** (as described above) in **both sides** (`IdentityUser` and `IdentityUserDto` in this case) in order to copy the value to the target object. Otherwise, it doesn't copy the value even if it does exists in the source object (`identityUser` in this example). There are some ways to overload this restriction.
+
+#### MappingPropertyDefinitionChecks
+
+`MapExtraPropertiesTo` gets an additional parameter to control the definition check for a single mapping operation:
+
+````csharp
+identityUser.MapExtraPropertiesTo(
+    identityUserDto,
+    MappingPropertyDefinitionChecks.None
+);
+````
+
+> Be careful since `MappingPropertyDefinitionChecks.None` copies all extra properties without any check. `MappingPropertyDefinitionChecks` enum has other members too.
+
+If you want to completely disable definition check for a property, you can do it while defining the extra property (or update an existing definition) as shown below:
+
+````csharp
+ObjectExtensionManager.Instance
+    .AddOrUpdateProperty<IdentityUser, string>(
+        "SocialSecurityNumber",
+        options =>
+        {
+            options.CheckPairDefinitionOnMapping = false;
+        });
+````
+
+#### Ignored Properties
+
+You may want to ignore some properties on a specific mapping operation:
+
+````csharp
+identityUser.MapExtraPropertiesTo(
+    identityUserDto,
+    ignoredProperties: new[] {"MySensitiveProp"}
+);
+````
+
+Ignored properties are not copied to the target object.
+
+#### AutoMapper Integration
+
+If you're using the [AutoMapper](https://automapper.org/) library, the ABP Framework also provides an extension method to utilize the `MapExtraPropertiesTo` method defined above.
+
+You can use the `MapExtraProperties()` method inside your mapping profile.
+
+````csharp
+public class MyProfile : Profile
+{
+    public MyProfile()
+    {
+        CreateMap<IdentityUser, IdentityUserDto>()
+            .MapExtraProperties();
+    }
+}
+````
+
+It has the same parameters with the `MapExtraPropertiesTo` method.
+
+## Entity Framework Core Database Mapping
+
+If you're using the EF Core, you can map an extra property to a table field in the database. Example:
+
+````csharp
+ObjectExtensionManager.Instance
+    .AddOrUpdateProperty<IdentityUser, string>(
+        "SocialSecurityNumber",
+        options =>
+        {
+            options.MapEfCore(b => b.HasMaxLength(32));
+        }
+    );
+````
+
+See the [Entity Framework Core Integration document](Entity-Framework-Core.md) for more.

docs/en/Object-To-Object-Mapping.md

@@ -145,6 +145,23 @@ options.AddProfile<MyProfile>(validate: true);
 
 > If you have multiple profiles and need to enable validation only for a few of them, first use `AddMaps` without validation, then use `AddProfile` for each profile you want to validate.
 
+### Mapping the Object Extensions
+
+[Object extension system](Object-Extensions.md) allows to define extra properties for existing classes. ABP Framework provides a mapping definition extension to properly map extra properties of two objects.
+
+````csharp
+public class MyProfile : Profile
+{
+    public MyProfile()
+    {
+        CreateMap<User, UserDto>()
+            .MapExtraProperties();
+    }
+}
+````
+
+It is suggested to use the `MapExtraProperties()` method if both classes are extensible objects (implement the `IHasExtraProperties` interface). See the [object extension document](Object-Extensions.md) for more.
+
 ## Advanced Topics
 
 ### IObjectMapper<TContext> Interface