Chrome 58 Beta: IndexedDB 2.0, an improvement to iframe navigation, and immersive full screen for PWAs
Tuesday, March 21, 2017
IndexedDB 2.0
The IndexedDB 2.0 standard is now fully supported in Chrome, making it simpler to work with large data sets in the browser. IDB 2.0 features new schema management, bulk action methods, and more standardized handling of failures.
The structure of a site’s database has large performance impacts and can be difficult to change. To simplify updates, object stores and indexes can now be renamed in-place after a refactoring. Sites can also use more natural keys without worrying about a performance penalty thanks to binary keys, which allow compact representations for custom keys.
Data retrieval is easier with the getKey() and openKeyCursor() methods, which also provide better performance when only a database key is needed. The new continuePrimaryKey() cursor method makes it easier to divide large data access across transactions and page loads without worrying about duplicate primary keys. The getAll() and getAllKeys() methods allow bulk recovery of entire datasets without the need for a cursor.
An improvement to iframe navigation
Third-party content, such as advertising, that automatically redirects the page can annoy users and create security issues. Because of this, developers are able to put third-party content inside sandboxed iframes to prevent this behavior. However, in some cases this type of content needs to navigate the top-level page when clicked, like a standard advertisement.
To address this, Chrome 58 now supports the new iframe sandbox keyword allow-top-navigation-by-user-activation. This keyword gives sandboxed iframes the ability to navigate the top-level page when triggered by user interaction, while still blocking auto-redirects.
Immersive full screen for PWAs
When Progressive Web Apps (PWAs) are launched from the Android Home screen, they launch in a standalone app-like mode that hides the omnibox. This helps create an engaging user experience, and frees up screen space for content. However, for even more immersive experiences like games, video players, or other rich content, other mobile UI elements such as the system bars can still be a distraction.
Now PWAs can provide a fully immersive experience by setting display: fullscreen in their web app manifest, which hides non-app UI when the site is launched from the home screen.
A PWA launched from the home screen (left), launched from the home screen in standalone mode (middle), and launched from the home screen in fullscreen mode (right).
Other features in this release
- Workers and SharedWorkers can now be created using data: URLs, making development with Workers more secure by giving them an opaque origin.
- PointerEvents.getCoalescedEvents() allows developers to access all input events since the last time a PointerEvent was delivered, making it easier for drawing apps to create smoother curves using a precise history of points.
- Developers can now customize Chrome’s native media controls such as the download, fullscreen and remoteplayback buttons using the new ControlsList API.
- On Chrome for Android, sites installed using the improved Add to Homescreen flow will be allowed to autoplay audio and video served from origins included in the manifest’s scope without restrictions.
- On Chrome for Android, videos using the autoplay attribute will be paused when offscreen and resumed when back in view to preserve consistency across browsers.
- Sites can now access the approximate range of colors supported by Chrome and output devices using the color-gamut Media Query.
- Instead of manually resetting multiple layout properties like float and clear, sites can now add a new block-formatting context using display: flow-root.
- To improve JavaScript parsing time, SVGPoint, SVGRect, and SVGMatrix have been transferred to new interfaces outside of Geometry.
- Using removeRange(), a new Selection API function, developers can now programmatically remove a specified text Range.
- The PointerEvent.tangentialPressure and PointerEvent.twist attributes are now supported on Chrome for Mac to provide more information to stylus devices and painting apps.
- To simplify developer experience, trailing commas are now allowed in JavaScript for formal parameter and argument lists.
- The WebAudio API’s new playback AudioContextLatencyCategory enables the developer to easily make conscious tradeoffs between latency, power, and CPU efficiency.
Deprecations and interoperability improvements
- Apple-interchange-newline, Apple-converted-space, Apple-paste-as-quotation, Apple-style-span, and Apple-tab-span have been deprecated as they are non-standard CSS classes.
- usemap attributes now use case-sensitive matching rather than compatibility caseless to better align with spec.
- Sites must now use HTTPS when requesting notification permissions or creating non-persistent local notifications with the Notifications API, in accordance with Chrome's policy around powerful features.
- To better align with spec, cancelBubble is now considered an alias to stopPropagation() when set to true, and does not do anything when set to false.
- Top-level navigations to data: URLs have been deprecated to further protect users from spoofing and phishing attempts.
- An instance of HTMLEmbedElement or HTMLObjectElement can no longer be called as a function, since the legacy caller has been removed.
- To improve interoperability, Selection.addRange() now ignores an additional range if it overlaps with an existing range, rather than merging the two ranges.
- Encrypted Media Extensions transmitted over non-secure origins has been deprecated per Chrome's policy around powerful features and in compliance with the spec.
- The AudioBuffer constructor now accepts the sampleRate member of an AudioBufferOptions dictionary instead of a context argument, simplifying the interface and emphasizing that AudioBuffers can be shared between AudioContexts.
- The synchronous FileReaderSync API has been deprecated in service workers, as the service worker spec requires all types of synchronous requests to be initiated outside of a service worker.
- The motion-path, motion-offset, and motion-rotation CSS properties have been removed in favor of the new versions: offset-path, offset-distance, offset-rotate.
- When accessing Selection API properties like selectionDirection, selectionStart, and selectionEnd, Chrome will now return null when it would have thrown an InvalidStateError DOMException.
- Rather than silently clamping offset values that were too large, the Selection API’s setBaseAndExtent() now throws an IndexSizeError DOMException to better align with spec.
- Rather than silently failing for DocumentType node inputs, the Selection API’s setBaseAndExtent(), extend(), and collapse() now throw InvalidNodeTypeError DOMException to better align with spec.
- The AudioSourceNode interface has been removed as it was not part of the WebAudio spec.
- The webkitdropzone attribute has been removed as it was not widely adopted.
Posted by Victor Costan, IndexedDB Interloper