Privacy/Reviews/Feature Detection API

Document Overview

Feature/Product:	Feature Detection API
Projected Feature Freeze Date:	(tbd)
Product Champions:	Caitlin Galimidi, Alphan Chen, Ehsan Akhgari
Privacy Champions:	Curtis Koenig
Security Contact:	Paul Theriault
Document State:	[NEW]

Timeline:

Architectural Overview:	(date TBD)
Recommendation Meeting:	(date TBD)
Review Complete ETA:	tbd

Architecture

In this section, the product's architecture is described. Any individual components or actors are identified, their "knowledge" or what data they store is identified, and data flow between components and external entities is described.

The main objective of this feature/product is: We have a number of use cases for detecting features in the platform which are not directly detectible through the usual way of feature detection (which is |"foo" in object|) because of various reasons, such as lack of sufficient permissions, or the information not being exposed through other parts of the platform, such as the amount of memory available on the device. This information is useful for Market Place because it needs to figure out whether to offer apps that will not work for the user because of things such as lack of support for a feature, not having enough memory, etc.

Note that the initial implementation of this API will be hidden behind a privilege which will only be available to the MarketPlace app. We're hoping to expose this API to unprivileged contexts once we get more experience with it.

Important note: this is not designed to replace the usual feature detection practices on the Web. This is only intended to address the use cases which are not possible to satisfy using the conventional feature detection techniques because the APIs are hidden behind permissions that the calling code does not possess.

Design Documents: https://wiki.mozilla.org/WebAPI/Navigator.hasFeature

Components

This API gives you knowledge about two separate classes of things. For the "api" namespace as described in https://wiki.mozilla.org/WebAPI/Navigator.hasFeature#.22api.22_namespace, the information is basically directly derivable from the user agent string.

For the "hardware" namespace as described in https://wiki.mozilla.org/WebAPI/Navigator.hasFeature#.22hardware.22_namespace, the API queries the OS to detect the amount of physical memory available to the OS. The returned values are always powers of two (for example, 256MB, 512MB, 1GB, etc.)

User Data Risk Minimization

In this section, the privacy champion will identify areas of user data risk and recommendations for minimizing the risk.

Alignment with Privacy Operating Principles

In this section, the privacy champion will identify how the feature lines up with Mozilla's privacy operating principles.

See Also: Privacy/Roadmap_2011#Operating_Principles:

Principle: Transparency / No Surprises

(How the feature addresses this)

Recommendations: (what can be improved)

Principle: Real Choice

Recommendations:

Principle: Sensible Defaults

Recommendations:

Principle: Limited Data

Recommendations:

Follow-up Tasks and tracking

What	Who	Bug	Details
[NEW] Initial Overview Discussion	?		Meeting time TBD