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Feature Engagement

The Feature Engagement component provides a client-side backend for displaying feature enlightenment or in-product help (IPH) with a clean and easy to use API to be consumed by the UI frontend. The backend behaves as a black box and takes input about user behavior. Whenever the frontend gives a trigger signal that in-product help could be displayed, the backend will provide an answer to whether it is appropriate to show it or not.

[TOC]

Objectives

We often add new features, but some are hard to find. Both new and old features could benefit from being surfaced for users that we believe would be the ones who benefit the most. This has lead to the effort of providing direct in-product help to our end users that should be extremely context aware to maximize the value of the new information.

Conceptually one could implement tracking whether In-Product Help should be displayed or not through a single preference for whether it has been shown before. However, that leads to a few issues that this component tries to solve:

Make showing In-Product Help context aware.
- If a user is continuously using a feature, there is no reason for Chrome to display In-Product Help for it.
- Other events might be required to have happened first that would make it more likely that the end user would be surprised and delighted when the In-Product Help in fact does show up.
  - Example: Having seen the Chrome offline dino 10 times the last week, the user might be happier if they are informed that they can download web pages exactly as a page successfully loads.
Tackle interactions between different In-Product Help features.
- If other In-Product Help has been shown within the current session, we might not want to show a different one.
- Whether we have shown a particular In-Product Help or not might be a precondition for whether we should show different one.
Users should be able to try out a feature on their own for some time before they see help.
- We should show In-Product Help only if they don't seem to use it, but we believe it would be helpful to them.
Share the same statistics framework across all of Chrome.
- Sharing a framework within Chrome makes it easier to track statistics and share queries about In-Product Help in a common way.
Make it simpler to add new In-Product Help for developers, but still enabling them to have a complex decision tree for when to show it.

Overview

Each In-Product Help is called a feature in this documentation. Every feature will have a few important things that are tracked, particularly whether the in-product help has been displayed, whether the feature the IPH highlights has been used and whether any required preconditions have been met. All of these are tracked within daily buckets. This tracking is done only locally on the device itself.

The client-side backend is feature agnostic and has no special logic for any specific features, but instead provides a generic API and uses a special configuration format to control how often IPH should be shown for end users. The configuration provides thresholds in the experiment params and compare these numbers to the local state and can be specified either on the client side, or on the server side.

Whenever the triggering condition for possibly showing IPH happens, the frontend asks the backend whether it should display the IPH. The backend then compares the current local state with the experiment params to see if they are within the given thresholds. If they are, the frontend is informed that it should display the IPH. The backend does not display any UI.

To ensure that there are not multiple IPHs displayed at the same time, the frontend also needs to inform the backend whenever the IPH has been dismissed.

In addition, since each feature might have preconditions that must be met within the time window configured for the experiment, the frontend needs to inform the backend whenever such events happen.

To ensure that it is possible to use whether a feature has been used or not as input to the algorithm to decide whether to show IPH and for tracking purposes, the frontend needs to inform whenever the feature has been used.

Lastly, some preconditions might require something to never have happened. The first time a user has an IPH available, that will typically be true, since the event just started being tracked so no interactions have been recorded yet. E.g. if a precondition is "the user has never opened the menu", and this has not been tracked before, the number of times that we have so far recorded that the user has opened the menu is 0, even if that is a common action for the user. Therefore, the framework supports requiring the IPH to have been available for a certain amount of days before being applicable. With the opening of menu scenario described above, we can configure the IPH to only be valid after the IPH has been available for at least N=14 days, before we say that the user has never opened the menu.

The backend will track all the state in-memory and flush it to disk when necessary to ensure the data is consistent across restarts of the application. The time window for how long this data is stored is configurable per IPH.

All of the local tracking of data will happen per Chrome user profile.

Developing a new In-Product Help Feature

You need to do the following things to enable your feature, all described in detail below.

Declare your feature and make it available to the feature_engagement::Tracker.
Start using the feature_engagement::Tracker class by notifying about events, and checking whether In-Product Help should be displayed.
Configure UMA.
Add a field trial configuration.

Declaring your feature

Naming

You need to create a base::Feature that represents your In-Product Help feature, that enables the whole feature to be controlled server side. The name of the constant should be of the form:

kIPH prefix
Your unique CamelCased name, for example GoatTeleportation.
Feature suffix.

The example listed above would end up as kIPHGoatTeleportationFeature.

The name member of the base::Feature struct should match the constant name, and be on the form:

IPH_ prefix
Your unique CamelCased name, for example GoatTeleportation.

Required Code Changes

There are also a few more places where the feature should be added, so overall you would have to add it to the following places:

//components/feature_engagement/public/feature_constants.cc:

To find the option that fits best for your use case, please read the section Configuring when to show in-product help below. The section explains when to use client side, server side, or a mix of client side and server side configuration, and guidance on whether the feature should be enabled or disabled by default.

For features configured only on the client side:
```
const base::Feature kIPHGoatTeleportationFeature{"IPH_GoatTeleportation",
                                                 base::FEATURE_ENABLED_BY_DEFAULT};
```
For features configured only on the server side:
```
const base::Feature kIPHGoatTeleportationFeature{"IPH_GoatTeleportation",
                                                 base::FEATURE_DISABLED_BY_DEFAULT};
```

//components/feature_engagement/public/feature_constants.h:

extern const base::Feature kIPHGoatTeleportationFeature;

//components/feature_engagement/public/feature_list.cc:
- Add to const base::Feature* kAllFeatures[].
//components/feature_engagement/public/feature_list.h:
- DEFINE_VARIATION_PARAM(kIPHGoatTeleportationFeature, "IPH_GoatTeleportation");
- VARIATION_ENTRY(kIPHGoatTeleportationFeature)

If the feature will also be used from Java, also add it to: org.chromium.components.feature_engagement.FeatureConstants as a String constant.

Required UMA Changes

To enable UMA tracking, you need to make the following changes to the metrics configuration:

Add feature to the histogram variant IPHFeatures in: //tools/metrics/histograms/metadata/feature_engagement/histograms.xml.
- The variant name must match the base::Feature name member of your feature.
Add feature to the actions file at: //tools/metrics/actions/actions.xml.
- The suffix must match the base::Feature name member with IPH_ stripped.
- Find the <action-suffix> entry at the end of the file, where the following <affected-action>s are listed:
  - InProductHelp.NotifyEvent.IPH
  - InProductHelp.NotifyUsedEvent.IPH
  - InProductHelp.ShouldTriggerHelpUI.IPH
  - InProductHelp.ShouldTriggerHelpUIResult.NotTriggered.IPH
  - InProductHelp.ShouldTriggerHelpUIResult.Triggered.IPH
  - InProductHelp.ShouldTriggerHelpUIResult.WouldHaveTriggered.IPH
- Add an alphebetically sorted entry to the list of <suffix>es like: <suffix name="GoatTeleportationFeature" label="For goat teleportation feature."/>

Using the feature_engagement::Tracker

To retrieve the feature_engagement::Tracker you need to use your platform specific way for how to retrieve a KeyedService. For example for desktop platforms and Android, you can use the feature_engagement::TrackerFactory in //chrome/browser/feature_engagement/tracker_factory.h to retrieve it from the Profile or BrowserContext:

feature_engagement::Tracker* tracker =
    feature_engagement::TrackerFactory::GetForBrowserContext(profile);

That service can be first of all used to notify the backend about events:

tracker->NotifyEvent("your_event_name");

In addition, it can tell you whether it is a good time to trigger the help UI:

bool trigger_help_ui =
    tracker->ShouldTriggerHelpUI(feature_engagement::kIPHGoatTeleportationFeature);
if (trigger_help_ui) {
    // Show IPH UI.
}

If feature_engagement::Tracker::ShouldTriggerHelpUI returns true, you must display the In-Product Help, as it will be tracked as if you showed it. In addition you are required to inform when the feature has been dismissed:

tracker->Dismissed(feature_engagement::kIPHGoatTeleportationFeature);

Inspecting whether IPH has already been triggered for a feature

Sometimes additional tracking is required to figure out if in-product help for a particular feature should be shown, and sometimes this is costly. If the in-product help has already been shown for that feature, it might not be necessary any more to do the additional tracking of state.

To check if the triggering condition has already been fulfilled (i.e. can not currently be triggered again), you can call:

// TriggerState is { HAS_BEEN_DISPLAYED, HAS_NOT_BEEN_DISPLAYED, NOT_READY }.
Tracker::TriggerState trigger_state =
    GetTriggerState(feature_engagement::kIPHGoatTeleportationFeature);

Inspecting this state requires the Tracker to already have been initialized, else NOT_READY is always returned. See IsInitialized() and AddOnInitializedCallback(...) for how to ensure the call to this is delayed.

A note about TriggerState naming

Typically, the FeatureConfig (see below) for any particular in-product help requires the configuration for event_trigger to have a comparator value of ==0, i.e. that it is a requirement that the particular in-product help has never been shown within the search window. The values of the TriggerState enum reflects this typical usage, whereas technically, this is the correct interpretation of the states:

HAS_BEEN_DISPLAYED: event_trigger condition is NOT met and in-product help will not be displayed if Tracker is asked.
HAS_NOT_BEEN_DISPLAYED: event_trigger condition is met and in-product help might be displayed if Tracker is asked.
NOT_READY: Tracker not fully initialized yet, so it is unable to inspect the state.

Inspecting whether IPH would have been triggered for a feature

Another way to check the internal state of the Tracker is to invoke feature_engagement::Tracker::WouldTriggerHelpUI which is basically the same as invoking feature_engagement::Tracker::ShouldTriggerHelpUI, but being allowed to ignore the state. It is still required to invoke feature_engagement::Tracker::ShouldTriggerHelpUI if in-product help should be shown.

WARNING: It is not guaranteed that invoking ShouldTriggerHelpUI(...) after this would yield the same result. The state might change in-between the calls because time has passed, other events might have been triggered, and other state might have changed.

Configuring when to show in-product help

To ensure that your in-product help triggers at the right time, you need to configure what the constraints are for showing. There are two ways of doing this: (1) Using a client side configuration, or (2) using a field trial configuration. It is also possible to use a mix of both (1) and (2).

Please read both sections below to figure out what fits your use-case best.

Client side configuration

Using client side configuration is a quick and easy approach to getting your IPH configured in a consistent way.

The client side configuration enables you to check in the configuration, and this configuration lives in feature_engagement::GetClientSideFeatureConfig. The format of this configuration is the same as when using a field trial, but is written in C++ instead of JSON. See Configuration Format below for details.

A client side feature configuration is merely used as a default configuration. It is possible to override any client side feature configuration using field trial configuration. See Field trial configuration below for details.

Enabled or disabled by default

When using client side configuration, you should define your base::Feature as base::FEATURE_ENABLED_BY_DEFAULT, since otherwise you will not be able to see the IPH. If you check in a client side configuration and enable the feature by default, you are done.

If you leave it disabled by default, you can still use these options to enable it:

Use demo mode described below.
Use a command line flag to manually enable the feature, e.g.:
```
chrome --enable-features=IPH_GoatTeleportationFeature
```
Use a field trial configuration to enable the feature, either using a configuration on the server side or a command line field trial configuration (advanced).

As an example for when leaving an IPH disabled by default could be helpful, imagine that your feature uses one main feature flag in addition to multiple IPH feature flags. You can still check in all the configuration locally, but leave the main feature flag and the IPHs off by default. This enables you to use a field trial to turn the IPHs on at the same time as your main feature flag. This could potentially help some features in two ways:

They do not need to guard invocations of ShouldTriggerHelpUI(...) for each IPH with their main feature flag, possibly leading to simpler code if the IPH related code is spread around in the code base.
They can control when data collection starts for the IPHs.

Field trial configuration

Using field trial configuration enables you to A/B test the IPH itself, e.g. whether it is worth it to have an IPH for a particular feature or not.

The field trial configuration support is built into Chrome and supports both local testing, and server side configuration. The configuration is written using JSON and the format is described here.

There are two things required to display an in-product help feature using this approach:

Enable the feature by any means, typically by adding your IPH feature to the enable_features list, and doing the same thing when using a server side configuration.
Specify a configuration for when to display in-product help.

To ensure you test your feature with what you are planning to ship, it is required to also configure the expected launch configuration as the main testing configuration. Basically this requires you to add a new section to //testing/variations/fieldtrial_testing_config.json for your feature. The format is described in the documentation linked above, but it will probably look something like this:

{
  "GoatTeleportationFeatureStudy": [
    {
      "platforms": ["android"],
      "experiments": [
        {
          "name": "GoatTeleportationFeatureLaunchConfig",
          "params": {
            "availability": ">=30",
            "session_rate": "<1",
            "event_used": "name:fun_event_happened;comparator:any;window:360;storage:360",
            "event_trigger": "name:fun_feature_iph_triggered;comparator:any;window:360;storage:360",
            "event_1": "name:related_fun_thing_happened;comparator:>=1;window:360;storage:360"
          },
          "enable_features": ["IPH_GoatTeleportationFeature"],
          "disable_features": []
        }
      ]
    }
  ],
  ...
}

When using a server side configuration, it is suggested to define the base::Feature as base::FEATURE_DISABLED_BY_DEFAULT, since there is no default configuration available.

Demo mode

The feature_engagement::Tracker supports a special demo mode, which enables a developer or testers to see how the UI looks like without using other more complicated configurations or even going through a particular complicated scenario.

The demo mode behaves differently than the code used in production where a client side or server side configuration is used. Instead, it has only a few rules:

Event model must be ready (happens early).
No other features must be showing at the moment.
The given feature must not have been shown before in the current session.

This basically leads to each selected IPH feature to be displayed once. The triggering condition code path must of course be triggered to display the IPH.

How to select a feature or features is described below.

Enabling all In-Product Help features in demo-mode

Go to chrome://flags
Find "In-Product Help Demo Mode" (#in-product-help-demo-mode-choice)
Select "Enabled"
Restart Chrome

Enabling a single In-Product Help feature in demo-mode

Go to chrome://flags
Find “In-Product Help Demo Mode” (#in-product-help-demo-mode-choice)
Select the feature you want with the "Enabled " prefix, for example for IPH_GoatTeleportationFeature you would select:
- Enabled IPH_GoatTeleportationFeature
Restart Chrome

Configuration Format

Each In-Product Help feature must have its own feature configuration FeatureConfig, which has 4 required configuration items that must be set, and then there can be an arbitrary number of additional preconditions (but typically on the order of 0-5).

The data types are listed below.

FeatureConfig

Format:

{
  "availability": "{Comparator}",
  "session_rate": "{Comparator}",
  "session_rate_impact": "{SessionRateImpact}",
  "blocked_by": "{BlockedBy}",
  "blocking": "{Blocking}",
  "event_used": "{EventConfig}",
  "event_trigger": "{EventConfig}",
  "event_???": "{EventConfig}",
  "tracking_only": "{Boolean}"
  "x_???": "..."
 }

Alternate format:

{
  "IPH_GoatTeleportationFeature_availability": "{Comparator}",
  "IPH_GoatTeleportationFeature_session_rate": "{Comparator}",
  "IPH_GoatTeleportationFeature_session_rate_impact": "{SessionRateImpact}",
  "IPH_GoatTeleportationFeature_blocked_by": "{BlockedBy}",
  "IPH_GoatTeleportationFeature_blocking": "{Blocking}",
  "IPH_GoatTeleportationFeature_event_used": "{EventConfig}",
  "IPH_GoatTeleportationFeature_event_trigger": "{EventConfig}",
  "IPH_GoatTeleportationFeature_event_???": "{EventConfig}",
  "IPH_GoatTeleportationFeature_tracking_only": "{Boolean}"
  "IPH_GoatTeleportationFeature_x_???": "..."
 }

The FeatureConfig fields availability, session_rate, event_used and event_trigger are required, and there can be an arbitrary amount of other event_??? entries. The fields can optionally have a feature name prefix (e.g. IPH_GoatTeleportationFeature_) as well, which is sometimes required to disambiguate between param names between different IPHs if they are combined into the same field trial.

availability REQUIRED
- For how long must an in-product help experiment have been available to the end user.
- The value of the Comparator is in a number of days.
- See Comparator below for details.
session_rate REQUIRED
- How many other in-product help have been displayed within the current end user session.
- The value of the Comparator is a count of total In-Product Help displayed in the current end user session.
- See Comparator below for details.
session_rate_impact
- Which other in-product help features showing the current IPH impacts.
- By default, a feature impacts every other feature.
- Defaults to all.
- See SessionRateImpact below for details.
blocked_by
- Which other in-product help features the current IPH is blocked by.
- By default, a feature is blocked by any other feature.
- Defaults to all.
- See BlockedBy below for details.
blocking
- Which other in-product help features showing the current IPH blocks.
- By default, a feature blocks every other feature.
- Defaults to all.
- See Blocking below for details.
event_used REQUIRED
- Relates to what the in-product help wants to highlight, i.e. teach the user about and increase usage of.
- This is typically the action that the In-Product Help should stimulate usage of.
- Special UMA is tracked for this.
- See EventConfig below for details.
event_trigger REQUIRED
- Relates to the times in-product help is triggered.
- Special UMA is tracked for this.
- See EventConfig below for details.
event_???
- Similar to the other event_ items, but for all other preconditions that must have been met.
- Name must match /^event_[a-zA-Z0-9-_]+$/ and not be event_used or event_trigger.
- See EventConfig below for details.
tracking_only
- Set to true if in-product help should never trigger.
- Tracker::ShouldTriggerHelpUI(...) will always return false, but if all other conditions are met, it will still be recorded as having been shown in the internal database and through UMA.
- This is meant to be used by either local tests or for comparisons between different experiment groups.
- If you want to later transition users with this flag set to true to in fact display in-product help, you might want to use a different EventConfig::name for the event_trigger configuration than the non-tracking configuration.
- Defaults to false.
- See Boolean below for details.
x_???
- Any parameter starting with x_ is ignored by the feature engagement tracker.
- A typical use case for this would be if there are multiple experiments for the same in-product help, and you want to specify different strings to use in each of them, such as:
```
"x_promo_string": "IDS_GOATTELEPORTATION_PROMO_2"
```
- Failing to use an x_-prefix for parameters unrelated to the FeatureConfig will end up being recorded as FAILURE_UNKNOWN_KEY in the InProductHelp.Config.ParsingEvent histogram.

Examples

Trigger the IPH once every 4 months if the download_completed event has triggered at least one time and the download_home_iph_trigger (download home IPH) hasn't triggered in the last 90 days. The feature needs to have been available for more than a month and no other IPH has been shown for the current session.

The event we are trying to increase the usage of is download_home_opened and is allowed to have previously happened for the IPH to trigger.

{
  "availability": ">=30",
  "session_rate": "<1",
  "event_used": "name:download_home_opened;comparator:any;window:90;storage:360",
  "event_trigger": "name:download_home_iph_trigger;comparator:==0;window:90;storage:360",
  "event_1": "name:download_completed;comparator:>=1;window:120;storage:180"
}

Trigger the IPH once per week, up to 3 times per year as long as the user hasn't triggered shopping_list_track_price_from_menu. The IPH should be ready to trigger as long as no other IPH has been shown.

{
  "availability": ">=0",
  "session_rate": "<1",
  "event_used": "name:shopping_list_track_price_from_menu;comparator:==0;window:360;storage:360",
  "event_trigger": "name:shopping_list_menu_item_iph_triggered;comparator:==0;window:7;storage:7",
  "event_trigger_1": "name:shopping_list_menu_item_iph_triggered;comparator:<3;window:360;storage:360"
}

EventConfig

Format: name:{std::string};comparator:{COMPARATOR};window:{uint32_t};storage:{uint32_t}

The EventConfig is a semi-colon separate data structure with 4 key-value pairs, all described below:

name
- The name (unique identifier) of the event.
- Must match what is used in client side code.
- Must only contain alphanumeric, dash and underscore.
  - Specifically must match this regex: /^[a-zA-Z0-9-_]+$/
- Value client side data type: std::string
comparator
- The comparator for the event. See Comparator below.
window
- Search for this occurrences of the event within this window.
- The value must be given as a number of days.
- For value N, the following holds:
  - 0 Nothing should be counted.
  - 1 |current_day| should be counted.
  - 2+ |current_day| plus |N-1| more days should be counted.
- Value client side data type: uint32_t
storage
- Store client side data related to events for this event minimum this long.
- The value must be given as a number of days.
- For value N, the following holds:
  - 0 Nothing should be stored.
  - 1 |current_day| should be stored.
  - 2+ |current_day| plus |N-1| more days should be stored.
- The value should not exceed 10 years (3650 days).
- Value client side data type: uint32_t
- Whenever a particular event is used by multiple features, the maximum value of all storage is used as the storage window.

Examples

The user_opened_app_menu event hasn't triggered in the last two weeks. Keep existing events for 90 days.

name:user_opened_app_menu;comparator:==0;window:14;storage:90

The user_has_seen_dino event has occurred at least 5 times in the last 30 days. Keep existing events for about a year.

name:user_has_seen_dino;comparator:>=5;window:30;storage:360

The user_has_seen_wifi event has occurred at least once in the last 30 days. Keep existing events for 6 months.

name:user_has_seen_wifi;comparator:>=1;window:30;storage:180

Comparator

Format: {COMPARATOR}[value]

The following comparators are allowed:

< less than
> greater than
<= less than or equal
>= greater than or equal
== equal
!= not equal
any always true (no value allowed)

Other than any, all comparators require a value.

Examples

>=10
==0
any
<15

Boolean

Format: [true|false]

The following values are allowed:

true
false

The value must be quoted (like all the other values).

Examples

true
false
TRUE
FALSE
True
False

SessionRateImpact

Format: [all|none|comma-separated list]

all means this feature impacts every other feature regarding their session_rate calculations. This is the default.
none means that this feature does not impact any other features regarding the session_rate. This feature may therefore be shown an unlimited amount of times, without making other features go over their session_rate config.
[comma-separated list] means that this feature only impacts the particular features listed. Use the base::Feature name of the feature in the list. For features in the list, this feature will affect their session_rate conditions, and for features not in the list, this feature will not affect their session_rate calculations.
- It is NOT valid to use the feature names all or none. They must only be used alone with no comma, at which point they work as described above.

Examples

all
none
IPH_DownloadHome
IPH_DownloadPage,IPH_DownloadHome

BlockedBy

Format: [all|none|comma-separated list]

all means this feature is blocked by any other feature that is currently showing. This is the default.
none means that this feature is not blocked by any other features. This feature may therefore be shown unrestricted by the currently showing features.
[comma-separated list] means that this feature is only blocked by the particular features listed. Use the base::Feature name of the feature in the list.
- It is NOT valid to use the feature names all or none. They must only be used alone with no comma, at which point they work as described above.

Examples

all
none
IPH_DownloadHome
IPH_DownloadPage,IPH_DownloadHome

Blocking

Format: [all|none]

all means this feature blocks every other feature regarding their IsBlocked calculations. This is the default.
none means that this feature does not block any other features regarding the IsBlocked calculation.

Examples

all
none

Manual testing using field trial configurations

Usually, the options for testing IPHs provided in Configuring when to show in-product help are enough for most features. However, if you need to manually test your feature and want to test the whole flow from parsing field trial parameters to enabling your feature, the steps for this are described below.

It is possible to test the whole backend from parsing the configuration, to ensuring that help triggers at the correct time. To do that you need to provide a JSON configuration file, that is then parsed to become command line arguments for Chrome, and after that you can start Chrome and verify that it behaves correctly.

Create a file which describes the configuration you are planning on testing with, and store it. In the following example, store the file DownloadStudy.json:

{
  "DownloadStudy": [
    {
      "platforms": ["android"],
      "experiments": [
        {
          "name": "DownloadExperiment",
          "params": {
            "availability": ">=30",
            "session_rate": "<1",
            "event_used": "name:download_home_opened;comparator:any;window:90;storage:360",
            "event_trigger": "name:download_home_iph_trigger;comparator:any;window:90;storage:360",
            "event_1": "name:download_completed;comparator:>=1;window:120;storage:180"
          },
          "enable_features": ["IPH_DownloadHome"],
          "disable_features": []
        }
      ]
    }
  ]
}

Use the field trial utility to convert the JSON configuration to command line arguments:
```
python ./tools/variations/fieldtrial_util.py DownloadStudy.json android shell_cmd
```

Pass the command line along to the binary you are planning on running.

Note: For Android you need to ensure that all arguments are are within one set of double quotes. In particular, for the Android target chrome_public_apk it would be:

./out/Debug/bin/chrome_public_apk run --args "--force-fieldtrials=DownloadStudy/DownloadExperiment --force-fieldtrial-params=DownloadStudy.DownloadExperiment:availability/>=30/event_1/name%3Adownload_completed;comparator%3A>=1;window%3A120;storage%3A180/event_trigger/name%3Adownload_home_iph_trigger;comparator%3Aany;window%3A90;storage%3A360/event_used/name%3Adownload_home_opened;comparator%3Aany;window%3A90;storage%3A360/session_rate/<1 --enable-features=IPH_DownloadHome<DownloadStudy"

Printf debugging

Several parts of the feature engagement tracker has some debug logging available. To see if the current checked in code covers your needs, try starting a debug build of chrome with the following command line arguments:

--vmodule=tracker_impl*=2,event_model_impl*=2,persistent_availability_store*=2,chrome_variations_configuration*=3

Development of `//components/feature_engagement`

Testing

To compile and run tests, assuming the product out directory is out/Debug, use:

ninja -C out/Debug components_unittests ;
./out/Debug/components_unittests \
  --test-launcher-filter-file=components/feature_engagement/components_unittests.filter

When adding new test suites, also remember to add the suite to the filter file: //components/feature_engagement/components_unittests.filter.

In-product Help Analysis Guideline

See this doc

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

feature_engagement

feature_engagement

README.md

Feature Engagement

Objectives

Overview

Developing a new In-Product Help Feature

Declaring your feature

Naming

Required Code Changes

Required UMA Changes

Using the feature_engagement::Tracker

Inspecting whether IPH has already been triggered for a feature

A note about TriggerState naming

Inspecting whether IPH would have been triggered for a feature

Configuring when to show in-product help

Client side configuration

Enabled or disabled by default

Field trial configuration

Demo mode

Enabling all In-Product Help features in demo-mode

Enabling a single In-Product Help feature in demo-mode

Configuration Format

FeatureConfig

EventConfig

Comparator

Boolean

SessionRateImpact

BlockedBy

Blocking

Manual testing using field trial configurations

Printf debugging

Development of `//components/feature_engagement`

Testing

In-product Help Analysis Guideline

Files

feature_engagement

Directory actions

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Directory actions

More options

Latest commit

History

feature_engagement

Folders and files

parent directory

README.md

Feature Engagement

Objectives

Overview

Developing a new In-Product Help Feature

Declaring your feature

Naming

Required Code Changes

Required UMA Changes

Using the feature_engagement::Tracker

Inspecting whether IPH has already been triggered for a feature

A note about TriggerState naming

Inspecting whether IPH would have been triggered for a feature

Configuring when to show in-product help

Client side configuration

Enabled or disabled by default

Field trial configuration

Demo mode

Enabling all In-Product Help features in demo-mode

Enabling a single In-Product Help feature in demo-mode

Configuration Format

FeatureConfig

EventConfig

Comparator

Boolean

SessionRateImpact

BlockedBy

Blocking

Manual testing using field trial configurations

Printf debugging

Development of //components/feature_engagement

Testing

In-product Help Analysis Guideline

Development of `//components/feature_engagement`