# User Education component library This library contains the code that will allow you to implement **In-Product-Help (IPH)** and **Tutorials** in any framework, as well as display the **"New" Badge** on menus and labels. [TOC] ## Upstream dependencies Familiarity with these libraries are strongly recommended; feel free to reach out to their respective OWNERS if you have any questions. * [UI Interaction](/ui/base/interaction/README.md) * [ElementTracker](/ui/base/interaction/element_tracker.h) - supplies anchor points for help bubbles * [InteractionSequence](/ui/base/interaction/interaction_sequence.h) - describes the situations in which a Tutorial advances to the next step * [Feature Engagement](/components/feature_engagement/README.md) - used to evaluate triggering conditions for IPH and New Badge. ## Directory structure * [common](./common) - contains platform- and framework-agnostic APIs for working with `HelpBubble`s, **IPH**, and **Tutorials**. * [test](./test) - contains common code for testing user education primitives * [views](./views) - contains code required to display a `HelpBubble` in a Views-based UI, as well as **"New" Badge** primitives. * [webui](./webui/README.md) - contains code required to display a `HelpBubble` on a WebUI surface. ## Application integration The necessary IPH services have already been implemented in Chrome. If you are interested in extending User Education to another platform, see the [section](#Adding-User-Education-to-your-application) below. *Note: The rest of this document introduces User Education concepts and focuses on using existing services to create in-product help experiences.* # Programming API ## Help bubbles The core presentation element for both IPH and Tutorials is the [HelpBubble](./common/help_bubble.h). A `HelpBubble` is a blue bubble that appears anchored to an element in your application's UI and which contains information about that element. For example, a `HelpBubble` might appear underneath the profile button the first time the user starts Chrome after adding a second profile, showing the user how they can switch between profiles. Different UI frameworks have different `HelpBubble` implementations; for example, [HelpBubbleViews](./views/help_bubble_factory_views.h). Each type of `HelpBubble` is created by a different [HelpBubbleFactory](./common/help_bubble_factory.h), which is registered at startup in the global [HelpBubbleFactoryRegistry](./common/help_bubble_factory_registry.h). So for example, Chrome registers separate factories for Views, WebUI, and a Mac-specific factory that can attach a Views-based `HelpBubble` to a Mac native menu. When it comes time to actually show the bubble, the `HelpBubbleFactoryRegistry` will need two things: * The `TrackedElement` the bubble will be anchored to * The [HelpBubbleParams](./common/help_bubble_params.h) describing the bubble The `HelpBubbleFactoryRegistry` will search its registered factories for one able to produce a help bubble in the framework that sees this element. It can then create our help bubble with the given `HelpBubbleParams`. You will notice that this is an extremely bare-bones system. ***You are not expected to call `HelpBubbleFactoryRegistry` directly!*** Rather, the IPH and Tutorial systems use this API to show help bubbles. ## In-Product Help (IPH) In-Product Help is the simpler of the two ways to display help bubbles, and can even be the entry point for a Tutorial. IPH are: * **Spontaneous** - they are shown to the user when a set of conditions are met; the user does not choose to see them. * **Rate-limited** - the user will only ever see a specific IPH a certain number of times, and will only see a certain total number of different IPH per session. * **Simple** - only a small number of templates approved by UX are available, for different kinds of User Education journeys. In the code, an IPH is described by a `FeaturePromo`. Your application will provide a [FeaturePromoController](./common/feature_promo_controller.h) with a [FeaturePromoRegistry](./common/feature_promo_registry.h). In order to add a new IPH, you will need to: 1. Add the `base::Feature` corresponding to the IPH. 2. Register the appropriate [FeaturePromoSpecification](./common/feature_promo_specification.h) describing your IPH journey ([Registering your IPH](#Registering-your-IPH)). 3. Configure the Feature Engagement backend for your IPH journey ([Configuring when your IPH runs](#Configuring-when-your-IPH-runs)). 4. Add hooks into your code to show/hide your IPH and dispatch events ([Talking to the FE backend](#Talking-to-the-FE-backend)). 5. Enable the feature via a trade study or Finch. ![How to implement IPH diagram](images/iph-diagram.png) In reality, you will likely never interact directly with the `FeaturePromoController`. In Chrome, these methods are wrapped by the `BrowserWindow`. You may access them by calling: - `BrowserWindow::MaybeShowFeaturePromo()` - `BrowserWindow::MaybeShowStartupFeaturePromo()` - `BrowserWindow::CloseFeaturePromo()` - `BrowserWindow::CloseFeaturePromoAndContinue()` ### Registering your IPH You will want to create a `FeaturePromoSpecification` and register it with `FeaturePromoRegistry::RegisterFeature()`. There should be a common function your application uses to register IPH journeys during startup; in Chrome it's [`MaybeRegisterChromeFeaturePromos()`](../../chrome/browser/ui/views/frame/browser_view.cc). There are several factory methods on FeaturePromoSpecification for different types of IPH: * **CreateForToastPromo** - creates a small, short-lived promo with no buttons that disappears after a short time. * These are designed to point out a specific UI element; you will not expect the user to interact with the bubble. * Because of this a screen reader message and accelerator to access the relevant feature are required; this will be used to make sure that screen reader users can find the thing the bubble is talking about. * **CreateForSnoozePromo** - creates a promo with "got it" and "remind me later" buttons and if the user picks the latter, snoozes the promo so it can be displayed again later. * **CreateForTutorialPromo** - similar to `CreateForSnoozePromo()` except that the "got it" button is replaced by a "learn more" button that launches a Tutorial. * **CreateForLegacyPromo (DEPRECATED)** - creates a toast-like promo with no buttons, but which does not require accessible text and has no or a long timeout. *For backwards compatibility with older promos; do not use.* You may also call the following methods to add additional features to a bubble: * **SetBubbleTitleText()** - adds an optional title to the bubble; this will be in a larger font above the body text. * **SetBubbleIcon()** - adds an optional icon to the bubble; this will be displayed to the left (right in RTL) of the title/body. * **SetBubbleArrow()** - sets the position of the arrow relative to the bubble; this in turn changes the bubble's default orientation relative to its anchor. These are advanced features * **SetInAnyContext()** - allows the system to search for the anchor element in any context rather than only the window in which the IPH is triggered. * **SetAnchorElementFilter()** - allows the system to narrow down the anchor from a collection of candidates, if there is more than one element maching the anchor's `ElementIdentifier`. ### Configuring when your IPH runs The Feature Engagement (FE) backend does all the heavy-lifting when it comes to showing your IPH at the right time. All you need to do is configure how often your IPH should show and how it interacts with other IPH. You will need to become familiar with the terminology in the [FE docs](/components/feature_engagement/README.md), but you will instead create the configuration through the [FeatureConfig API](/components/feature_engagement/public/feature_configurations.cc). ### Talking to the FE backend Now that the IPH feature is created and configured, you will need to add hooks into your code to interact with the FE backend. You should attempt to show the IPH at an appropriate point in the code. In Chrome, this would be a call to `BrowserWindow::MaybeShowFeaturePromo()`, or if your promo should run immediately at startup, `BrowserWindow::MaybeShowStartupFeaturePromo()`. You will also add additional calls to `feature_engagement::Tracker::NotifyEvent()` for events that should affect whether the IPH should display. * These events should also be referenced in the Feature Engagement configuration (`FeatureConfig`). * This should include the user actually engaging with the feature being promo'd. * You can retrieve the tracker and send an event in Chrome via `BrowserView::NotifyFeatureEngagementEvent()`. Optionally: you may add calls to programmatically end the promo when the user engages with your feature. In Chrome, you can use `BrowserWindow::CloseFeaturePromo()` or `BrowserWindow::CloseFeaturePromoAndContinue()`. ## Tutorials Tutorials are the more complicated, in-depth way to display a series of help bubbles. Often an IPH is an entry point to a Tutorial but Tutorials can also be launched from e.g. a "What's New" or "Tips" page. Tutorials are: * **Intentional** - the user must always opt-in to seeing a Tutorial. * **Repeatable** - the user may view a Tutorial any number of times, and may view any number of Tutorials. * **In-Depth** - a Tutorial can breadcrumb the user around the UI, requesting the user engage in any number of behaviors, and will respond to those actions. Your application will provide a [TutorialService](./common/tutorial_service.h) with a [TutorialRegistry](./common/tutorial_registry.h). In order to add a new Tutorial, you will need to: 1. Declare a [TutorialIdentifier](./common/tutorial_identifier.h) in an accessible location. 2. Register the `TutorialIdentifier` and [TutorialDescription](./common/tutorial_description.h) ([Defining and registering your tutorial](#Defining-and-registering-your-Tutorial)). 3. Create an entry point for the Tutorial, either by: * Directly calling `TutorialService::StartTutorial()` * Or registering an IPH using the `CreateForTutorialPromo()` factory method. This IPH will prompt the user to start your tutorial. Notice that compared to an IPH, the tutorial itself does not require any `base::Feature`, FE configuration, or Finch configuration. This is because the tutorial is always initiated by the user. However, the IPH that launches your tutorial will need to be implemented and configured as outlined above ([In-Produce Help (IPH)](#in_product-help-iph)). ### Defining and registering your Tutorial A [Tutorial](./common/tutorial.h) is a stateful, executable object that "runs" the Tutorial itself; since they can't be reused, one needs to be created every time the Tutorial is started. A [TutorialDescription](./common/tutorial_description.h) is the template from which a `Tutorial` is built. It describes each step your tutorial will show the user, similar to the `FeaturePromoSpecification` used to create an IPH. A `TutorialDescription` can be restarted, i.e. rebuilt into a new `Tutorial`, if you choose to allow it. There are only a few fields in a `TutorialDescription`: * **steps** - Contains a sequence of user actions, UI changes, and the help bubbles that will be shown in each step. * **histograms** - Must be populated if you want UMA histograms regarding user engagement with your Tutorial. * The preferred syntax is: ``` const char kMyTutorialHistogramPrefix[] = "MyTutorial"; tutorial_description.histograms = user_education::MakeTutorialHistograms( tutorial_description.steps.size()); ``` * The `kMyTutorialHistogramPrefix` needs to be declared as a local `const char[]` and have a globally-unique value. This will appear in UMA histogram entries associated with your tutorial. If this value is duplicated the histogram behavior will be undefined. * Note that this cannot be done automatically by the TutorialRegistry as the UMA histograms won't work without the static declarations implemented by the `TutorialHistogramsImpl<>` template class (via C++ template specialization magic). * **can_be_restarted** - If set to `true` the Tutorial will provide an option to restart on the last step, in case the user wants to see the Tutorial again. * Setting this to `false` (the default) will not prevent the user from triggering the Tutorial again via other means. `TutorialDescription::Step` is a bit more complex. Steps may either be created all at once with the omnibus constructor, or created with the default constructor and then have each field set individually. The fields of the struct are as follows: * Help bubble parameters: * **body_text_id** - Localized string ID. The result is placed into `HelpBubbleParams::body_text`. If not set, this Tutorial step is a "hidden step" and will have no bubble. * **title_text_id** - Localized string ID. The result is placed into `HelpBubbleParams::title_text`. * **element_id** - Specifies the UI element the step refers to. If this is not a hidden step, the bubble will anchor to this element. Mandatory unless `element_name` is set. * **arrow** - Specifies how the `HelpBubble` for this step will anchor to the target element. * Interaction sequence parameters; see [InteractionSequence](/ui/base/interaction/interaction_sequence.h) for details: * **step_type** - Specifies the triggering condition of this step. * **event_type** - If `step_type` is `kCustomEvent`, specifies the custom event the step will transition on. Ignored otherwise. * **name_elements_callback** - Allows either the current element or some other element to be "named" for use later in the Tutorial. This allows a Tutorial to remember elements that may otherwise be ambiguous or not have an `ElementIdentifier` before the Tutorial runs. * **element_name** - Specifies that the step will target an element named via `name_elements_callback` in a previous step, rather than using `element_id`. The element must have been named and still be visible. * **transition_only_on_event** - When `step_type` is `kShown` or `kHidden`, causes this step to start only when a UI element actively becomes visible or loses visibility. Corresponds to `InteractionSequence::StepBuilder::SetTransitionOnlyOnEvent()`. * **must_remain_visible** - Overrides the default "must remain visible" state of the underlying `InteractionSequence::Step`. Should only be set if the Tutorial won't work properly otherwise. Notes: * `TutorialDescription::Step` is copyable and a step can be added to the `steps` member of multiple related `TutorialDescription`s. * We are aware that the programming interface for `Step` is a little clunky; at some future point they will be moved to a builder pattern like `FeaturePromoSpecification`. * If you're not sure how to construct your Tutorial, reach out to one of the OWNERS of this library. Once you have defined your Tutorial; call `AddTutorial()` on the [TutorialRegistry](./common/tutorial_registry.h) provided by your application and pass both your `TutorialIdentifier` and your `TutorialDescription`. ## "New" Badge For implementation on adding a "New" Badge to Chrome, Googlers can refer to the following document: [New Badge How-To and Best Practices](https://goto.google.com/new-badge-how-to). # Adding User Education to your application There are a number of virtual methods that must be implemented before you can use these User Education libraries in a new application, mostly centered around localization, accelerators, and global input focus. Fortunately for Chromium developers, the browser already has the necessary support built in for Views, WebUI, and Mac-native context menus. You may refer to the following locations for an example that could be extended to other platforms such as ChromeOS: * [UserEducationService]( /chrome/browser/ui/user_education/user_education_service.h) - sets up the various registries and `TutorialService`. * [BrowserView](/chrome/browser/ui/views/frame/browser_view.cc#831) - sets up the `FeaturePromoController`. * [browser_user_education_service]( /chrome/browser/ui/views/user_education/browser_user_education_service.h) - registers Chrome-specific IPH and Tutorials. * Concrete implementations of abstract User Education base classes can be found in [c/b/ui/user_education](/chrome/browser/ui/user_education/) and [c/b/ui/views/user_education](/chrome/browser/ui/views/user_education/).