EnumField

With an EnumField<TEntity, TEnum> you can represent values from enums in your resource. An enum is useful for fields where you want to limit user choice to a predetermined set of values.

Generic types

An EnumField<TEntity, TEnum> is created with two generic type arguments:

• The TEntity argument must be a reference type that refers to the underlying entity of the resource.
• The TEnum argument must be a subtype of Enum.

Example usage

In our demo application, we use an enum to store an employee's work model. Here's the enum definition.

[JsonConverter(typeof(JsonStringEnumConverter))]
public enum WorkModels {
    'OnSite',
    'Hybrid',
    'Remote'
}

INFO

Enums are typically displayed as numeric indices. To display values as strings, you can add a [JsonConverter(typeof(JsonStringEnumConverter))] as attribute above the enum definition.

The enum is used in the employee model class.

public class Employee
{
    [Key]
    public int Id { get; init; }
    [Required]
    public WorkModels WorkModel { get; set; }
}

You can represent the property in the employee resource by adding it to the list of available fields:

public override IList<IResourceFieldBuilder> Fields()
{
    return 
    [
        EnumField<Employee, WorkModels>
            .Make("Work Model", nameof(Employee.WorkModel)),
    ];
}

Field display

An EnumField displays either the numeric index of its value or its text representation, depending on whether you've configured a string enum converter.

In Create and Update views, a user will see a dropdown select. If you have configured a string converter, the member names will be shown as values. Otherwise, a user will see indices of the enum members.

Visibility

The default visibility values are as follows:

Resource View	Default
Index	visible
Create	visible
Update	visible
Details	visible

You can change the visibility of the field for each view. Please note, however, that fields should remain visible on Create pages if the field is required by the entity model and if no default value is set.

Sorting

An EnumField can be made sortable by chaining a call to Sortable() after adding the field. Sorting will be performed in alphanumeric order, results will therefore depend on your database provider's enum representation.

public override IList<IResourceFieldBuilder> Fields()
{
    return 
    [
        EnumField<Employee, WorkModels>
            .Make("Work Model", nameof(Employee.WorkModel))
            .Sortable(),
    ];
}

Filters

We provide a default filter for enum fields. Simply chain a Filterable() method call after the field definition. The filter will consider all available enum values and present them as filter options in a dropdown menu for the user to choose from.

public override IList<IResourceFieldBuilder> Fields()
{
    return 
    [
        EnumField<Employee, WorkModels>
            .Make("Work Model", nameof(Employee.WorkModel))
            .Filterable(),
    ];
}