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Explainer https://github.com/WICG/navigation-api/blob/main/README.md Specification https://wicg.github.io/navigation-api/ Summary The window.navigation API provides the ability to intercept and initiate navigations, as well as introspect an application's history entries. This provides a more useful alternative to window.history and window.location, specifically aimed at the needs of single-page web applications. (Note: this API was formerly known as the app history API.) Blink component Blink>History <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EHistory> TAG review https://github.com/w3ctag/design-reviews/issues/605 https://github.com/w3ctag/design-reviews/issues/717 TAG review status Issues addressed Link to origin trial feedback summary https://docs.google.com/document/d/1oDtVhNJaDyEAqsthe07wJaGNVpt-g4TLB4A0-lU2lr4/edit?usp=sharing Risks Interoperability The biggest interoperability risk with this API is that it is building on a rocky foundation. The existing session history spec does not match browsers very well, and browsers do not match each other. Since this new API layers on top of the existing model, this could cause issues. We have attempted to address this via a solid and well-tested specification for the new API, as well as ongoing efforts in whatwg/html PR #6315 <https://github.com/whatwg/html/pull/6315> and elsewhere on the HTML Standard issue tracker <https://github.com/whatwg/html/issues?q=is%3Aopen+is%3Aissue+label%3A%22topic%3A+navigation%22%2C%22topic%3A+history%22%2C%22topic%3A+browsing+context%22> to reform the foundational parts of the specification. For example, although the navigation API's new events, such as currententrychange, are fired at well-specified times, there is an existing interop problem <https://github.com/whatwg/html/issues/1792> regarding the timing of popstate vs. hashchange events, which makes it difficult to write tests for the ordering of currententrychange vs. hashchange/popstate. Working on such existing interop issues and specification problems, and then expanding the navigation API test suite to cover any such interactions, is our team's top priority after this launch. See also this tracking issue <https://github.com/WICG/navigation-api/issues/221>. Regarding whether this new API will be implemented in other browsers, we have been encouraged by the consistent and positive collaboration with Gecko engineers, which has led to several API changes and a good amount of review. (We have no signal from WebKit.) Compatibility This has been the team's main focus for the last few months, as we burned through the list of potentially-compat-impacting issues <https://github.com/WICG/navigation-api/milestone/1>. In collaboration with Gecko this led to several improvements, such as the API rename (from app history), a change <https://github.com/WICG/navigation-api/issues/111> in how replacement navigations are requested, and the addition <https://github.com/WICG/navigation-api/issues/76> of an indicator for when a download is requested. We believe the remaining issues (3 at the time of writing) are manageable: - #72 <https://github.com/WICG/navigation-api/issues/72>: this will result in firing an event more often during extreme edge case scenarios involving replacement navigations, or in less-rare-but-still-rare scenarios involving the user clearing their history. Neither case should prove problematic. - #207 <https://github.com/WICG/navigation-api/issues/207>: the most likely solution will either be leaving things as they are, or changing the timing of an event in a way that will not disturb "normal" usage of the API. Although such a timing change could be risky if this API had wide deployment, we believe that changing the timing within a milestone or three would not be problematic if it ends up being desirable. - #202 <https://github.com/WICG/navigation-api/issues/202>: this issue is about the default for how focus is managed following a navigation API-intercepted navigation. We believe the currently-chosen default is probably the best, especially given testaments on that thread from the accessibility community and from web framework authors. However we have not yet closed the issue as we haven't concluded the discussion with Gecko engineers. Similar to #207, this would probably be changeable within a few milestones if necessary, without significant impact to sites using the API. And if we did change it, early-adopter sites could easily restore the previous behavior by changing the value of an option. Signals Gecko: No signal <https://github.com/mozilla/standards-positions/issues/543>. Initial positive opinions on the issue, and continued engagement on the design, but not yet an official position. WebKit: No signal <https://lists.webkit.org/pipermail/webkit-dev/2021-September/031987.html>. Web developers: Strongly positive <https://github.com/WICG/proposals/issues/20>. The initial public proposal, as well as the issue tracker and Twitter, has had great engagement and enthusiasm from developers. Origin trial feedback was also encouraging. In addition, we have several conversations going on with frameworks, libraries, and larger websites to ensure that we're solving the problems they see with today's history API. So far reactions have been either positive, or requesting that we add additional functionality (most notably #32 <https://github.com/WICG/app-history/issues/32>). Ergonomics Although this API layers onto the same underlying model as window.history, and will have well-specified interactions with it, the exact integrations may be confusing. (For example, navigation.navigate() will behave differently from history.pushState().) We've done our best to smooth over these rough edges where possible, but have favored making the navigation API pleasant to use over making it perfectly align with window.history. Activation This feature is hard to polyfill, but developers have managed to produce something that works in many cases: frehner/appHistory <https://github.com/frehner/appHistory> is one, and virtualstate/navigation <https://github.com/virtualstate/navigation> another. We've also seen a pattern where developers have existing history/navigation wrappers (e.g. router libraries or app-specific history and navigation code) which they can adapt with a new navigation API-based backend for browsers that support it. Security We believe the security risks of this feature are minimal because of how it is scoped to same-origin contiguous history entries, and similarly only allows interception of same-origin navigations. We also need to ensure that we don't allow "trapping" the user by preventing them from using their back button; the API is designed to prevent this. See the specification's security and privacy discussion <https://wicg.github.io/navigation-api/#security-privacy> for more. WebView Application Risks Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications? This feature does not introduce any changes to existing APIs. Debuggability This feature mostly has no need for extended tooling. crbug.com/1252940 <https://bugs.chromium.org/p/chromium/issues/detail?id=1252940> tracked adding the newly-introduced events to the Event Listener Breakpoints panel. Is this feature fully tested by web-platform-tests <https://chromium.googlesource.com/chromium/src/+/master/docs/testing/web_platform_tests.md> ? Yes <https://wpt.fyi/results/navigation-api?label=master&label=experimental&aligned> . These results show a strange number of failures for Chromium. We suspect this is due to the test runner on wpt.fyi, as running the tests locally, or in a live Chrome browser, does not exhibit the issue. See web-platform-tests/wpt#33590 <https://github.com/web-platform-tests/wpt/issues/33590>. Flag name NavigationApi Requires code in //chrome? False Tracking bug https://bugs.chromium.org/p/chromium/issues/detail?id=1183545 Launch bug https://bugs.chromium.org/p/chromium/issues/detail?id=1252954 Measurement https://chromestatus.com/metrics/feature/timeline/popularity/4056 Non-OSS dependencies Does the feature depend on any code or APIs outside the Chromium open source repository and its open-source dependencies to function? No. Sample links https://gigantic-honored-octagon.glitch.me/ https://selective-heliotrope-dumpling.glitch.me/ Estimated milestones We plan to land this API in M102. Link to entry on the Chrome Platform Status https://chromestatus.com/feature/6232287446302720 Links to previous Intent discussions Intent to Prototype <https://groups.google.com/a/chromium.org/g/blink-dev/c/R1D5xYccqb0/m/8ukfzdVSAgAJ> Intent to Experiment <https://groups.google.com/a/chromium.org/g/blink-dev/c/ki__L-IiR0Q/m/rG3OgSkKBQAJ> This intent message was generated by Chrome Platform Status <https://chromestatus.com/> and then cleaned up a good bit. -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAM0wra8BD%2Bea9fSiRGyPJeAZ2KknQe6c9Xmza5BS7O94ktjXiA%40mail.gmail.com.
