Validation Groups (Scenarios)

Validation Groups allow you to reuse a single Data Transfer Object (DTO) or Entity model across multiple business scenarios. Rather than duplicating a CreateUserDto and an UpdateUserDto, Sannr groups govern which checks fire contextually.

Defining Group Tags

By default, attributes fire under the null or "default" group. You can assign them specifically to tagged validation runs by supplying the Group property.

public class Product
{
    [Required] // Always evaluates
    public string Name { get; set; }

    // Only evaluates during the "Creation" execution path
    [Required(Group = "Creation")]
    public string InitialStock { get; set; }
    
    // Only evaluates when editing
    [Required(Group = "Update")]
    public string ChangeReasonId { get; set; }
}

Triggering Specific Groups

When executing validation, provide the explicitly named group string to the Context or Validator executor.

// Evaluate only the "Creation" rules AND default rules
var result = validator.ValidateAsync(model, group: "Creation");

// Integration with Minimal APIs Wrapper:
app.MapPost("/product", async (Validated<Product> request) =>
{
    // Evaluates with full group scoping automatically defined by your extension setup
});