Aspor Validation
Installation
Install-Package Aspor.Validation
Model Validation
The model validation will check if the properties of an object have the right value and fits into the schema.
Validation action
Aspor model validation differentiate between different validation action. Based on the executed action the validation will behave differently.
| Action | Http Method | Description |
|---|---|---|
| CREATE | POST | Used when a new object is created with initial properties. |
| UPDATE | PATCH | Used when an object is updated and some properties changes (supported with delta operation) |
| REPLACE | PUT | Used when an object is overridden (supported with delta operation) |
| DELETE | DELETE | Used when an object is deleted |
OData Delta validation
Aspor supported the OData Delta class
and will only validate the changed properties. So for instance, if you use the [Required] annotation for a field
which has not been changed, it will not have an impact on your validation result. Also allows the delta together with the
validation actions to exactly calculate if it is allowed to modify a certain field.
System Data Annotations
https://docs.microsoft.com/en-us/dotnet/api/system.componentmodel.dataannotations?view=net-5.0
Aspor Annotations
Aspor brings additional annotations to the already available system data annotations.
| Annotation | Parameters | Description |
|---|---|---|
| OnlyServer | Allows only the server to modify a certain property | |
| DisallowModification | Disallows the modification of a certain property | |
| AllowOnly | Action#ValidationAction | Allows only one validation action on a certain property (e.g. CREATE OR UPDATE) |
Example
[Table("projects")]
public class Project
{
[Key]
[OnlyServer]
public Guid Id { get; set; }
[OnlyServer]
public Guid WorkspaceId { get; set; }
[MinLength(4)]
[MaxLength(128)]
[Required]
public string Name { get; set; }
[MinLength(4)]
[MaxLength(128)]
[Required]
public string Discriminator { get; set; }
public bool Public { get; set; }
[InverseProperty("Project")]
public virtual IList<Board> Boards { get; set; }
}
Custom model validator annotation
Rule Validation
Rule validations allow to further improve model validation with domain specific checks.
The main different is, that the model validation can only be called when the entire object has been loaded or after
the object has been patched by an update request. During the validation the IServiceProvider is also available,
which allows you direct access to your database or other services (sync or async).
The rule validation can be integrated into your object by implementing the IRuleValidation for synchronous validation
and the IAsyncRuleValidation for asynchronous validation.
Example
We will extend our current project model with a custom rule validation that will prevent multiple projects with the same discriminator in a workspace. If already another project with the new discriminator is available, our validation will fail.
[Table("projects")]
public class Project : IAsyncRuleValidation
{
[Key]
[OnlyServer]
public Guid Id { get; set; }
[OnlyServer]
public Guid WorkspaceId { get; set; }
[MinLength(4)]
[MaxLength(128)]
[Required]
public string Name { get; set; }
[MinLength(4)]
[MaxLength(128)]
[Required]
public string Discriminator { get; set; }
public bool Public { get; set; }
[InverseProperty("Project")]
public virtual IList<Board> Boards { get; set; }
public async Task Validate(IServiceProvider services, ModelStateDictionary state, object instance)
{
//Aquire a new database context
DatabaseContext database = services.GetRequiredService<DatabaseContext>();
//Check if there is already another project with the same discriminator in the same workspace
//(make sure to exclude the current object from the check)
if (await database.Projects.Where(p => p.Id != Id && p.WorkspaceId == WorkspaceId && p.Discriminator == Discriminator).AnyAsync())
{
//Throw a model validation error
state.AddModelError("discriminator", "Project discriminator must be unique in a workspace");
}
}
}