Global Features

Global Feature system is used to enable/disable an application feature on development time. It is done on the development time, because some services (e.g. controllers) are removed from the application model and database tables are not created for the disabled features, which is not possible on runtime.

Global Features system is especially useful if you want to develop a reusable application module with optional features. If the final application doesn't want to use some of the features, it can disable these features.

If you are looking for a system to enable/disable features based on current tenant or any other condition, please see the Features document.

Installation

This package is already installed by default with the startup template. So, most of the time, you don't need to install it manually.

Using the ABP CLI

Open a command line window in the folder of the project (.csproj file) and type the following command:

abp add-package Volo.Abp.GlobalFeatures

Defining a Global Feature

A feature class is something like that:

[GlobalFeatureName("Shopping.Payment")]
public class PaymentFeature
{
    
}

Enable/Disable Global Features

Use GlobalFeatureManager.Instance to enable/disable a global feature.

// Able to Enable/Disable with generic type parameter.
GlobalFeatureManager.Instance.Enable<PaymentFeature>();
GlobalFeatureManager.Instance.Disable<PaymentFeature>();

// Also able to Enable/Disable with string feature name.
GlobalFeatureManager.Instance.Enable("Shopping.Payment");
GlobalFeatureManager.Instance.Disable("Shopping.Payment");

Global Features are disabled unless they are explicitly enabled.

Where to Configure Global Features?

Global Features have to be configured before application startup. Since the GlobalFeatureManager.Instance is a singleton object, one-time, static configuration is enough. It is suggested to enable/disable global features in PreConfigureServices method of your module. You can use the OneTimeRunner utility class to make sure it runs only once:

private static readonly OneTimeRunner OneTimeRunner = new OneTimeRunner();
public override void PreConfigureServices(ServiceConfigurationContext context)
{
  OneTimeRunner.Run(() =>
  {
  	GlobalFeatureManager.Instance.Enable<PaymentFeature>();
  });
}

Check for a Global Feature

GlobalFeatureManager.Instance.IsEnabled<PaymentFeature>()
GlobalFeatureManager.Instance.IsEnabled("Shopping.Payment")

Both methods return bool. So, you can write conditional logic as shown below:

if (GlobalFeatureManager.Instance.IsEnabled<PaymentFeature>())
{
    // Some strong payment codes here...
}

RequiresGlobalFeature Attribute

Beside the manual check, there is [RequiresGlobalFeature] attribute to check it declaratively for a controller or page. ABP returns HTTP Response 404 if the related feature was disabled.

[RequiresGlobalFeature(typeof(PaymentFeature))]
public class PaymentController : AbpController
{

}

Grouping Features of a Module

It is common to group global features of a module to allow the final application developer easily discover and configure the features. Following example shows how to group features of a module.

Assume that we've defined a global feature for Subscription feature of an Ecommerce module:

[GlobalFeatureName("Ecommerce.Subscription")]
public class SubscriptionFeature : GlobalFeature
{
    public SubscriptionFeature(GlobalModuleFeatures module)
        : base(module)
    {
    }
}

You can define as many features as you need in your module. Then define a class to group these features together:

public class GlobalEcommerceFeatures : GlobalModuleFeatures
{
    public const string ModuleName = "Ecommerce";

    public SubscriptionFeature Subscription => GetFeature<SubscriptionFeature>();
	
    public GlobalEcommerceFeatures(GlobalFeatureManager featureManager)
        : base(featureManager)
    {
        AddFeature(new SubscriptionFeature(this));
    }
}

Finally, you can create an extension method on GlobalModuleFeaturesDictionary:

public static class GlobalModuleFeaturesDictionaryEcommerceExtensions
{
    public static GlobalEcommerceFeatures Ecommerce(
        this GlobalModuleFeaturesDictionary modules)
    {
        return modules.GetOrAdd(
            GlobalEcommerceFeatures.ModuleName,
            _ => new GlobalEcommerceFeatures(modules.FeatureManager)
        ) as GlobalEcommerceFeatures;
  }

Then GlobalFeatureManager.Instance.Modules.Ecommerce() can be used to access the global features of your module. Examples usages:

GlobalFeatureManager.Instance.Modules.Ecommerce().Subscription.Enable();
GlobalFeatureManager.Instance.Modules.Ecommerce().EnableAll();