On Tuesday, January 13, 2026 at 2:37:15 PM UTC+9 Chromestatus wrote:
*Contact emails* [email protected] *Specification* https://www.w3.org/TR/2011/WD-html5-20110113/dnd.html#dom-datatransfer-dropeffect *Summary* The HTML5 Drag and Drop API allows web applications to handle drag-and-drop operations through a series of events: `dragstart`, `dragenter`, `dragover`, `dragleave`, `drop`, and `dragend`. During these events, the [`dataTransfer.dropEffect`]( https://www.w3.org/TR/2011/WD-html5-20110113/dnd.html#dom-datatransfer-dropeffect) property indicates which operation (copy, move, link, or none) should be performed. According to the [HTML5 specification]( https://www.w3.org/TR/2011/WD-html5-20110113/dnd.html#dndevents), the `dropEffect` value set by web applications during the last `dragover` event should be preserved and available in the subsequent `drop` event. However, Chromium-based browsers were overwriting the web application's `dropEffect` value with the browser's own negotiated operation before the `drop` event fired, breaking specification compliance and limiting developer control over drag-and-drop behavior. That spec link is quite outdated; it points to the 2011 snapshot. I'm curious if the spec has been updated since then. https://html.spec.whatwg.org/multipage/dnd.html#dom-datatransfer-dropeffect *Blink component* Blink>DataTransfer <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EDataTransfer%22> *Web Feature ID* draganddrop <https://webstatus.dev/features/draganddrop> *Motivation* The current behavior: - Violates the HTML5 specification: Contradicts the standardized behavior defined in the HTML5 Drag and Drop API - Breaks developer control: Removes the ability for web applications to manage their own drag-and-drop operations - Creates unpredictable UX: The operation indicated during drag (via cursor feedback) may not match what's available in the drop handler - Forces workarounds: Developers must store `dropEffect` values in global variables or custom data attributes rather than using the standard API - Limits functionality: Makes it impossible to build spec-compliant file managers, code editors, and other applications requiring sophisticated drag-and-drop *Initial public proposal* *No information provided* *Search tags* draganddrop <http:///features#tags:draganddrop>, dropEffect <http:///features#tags:dropEffect> *TAG review* *No information provided* *TAG review status* Not applicable *Risks* *Interoperability and Compatibility* *No information provided* *Gecko*: Shipped/Shipping *WebKit*: No signal ( https://github.com/WebKit/standards-positions/issues/596) *Web developers*: Strongly positive ( https://issues.chromium.org/issues/40068941) 42 upvotes on the associated Chromium issue *Other signals*: *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? None *Debuggability* No new functionality needed for debuggability *Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?* Yes This is a blink level change independent of platform implementation. *Is this feature fully tested by web-platform-tests <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?* Yes There are few manual WPTs like https://wpt.live/html/editing/dnd/drop/025.html which cover this feature. Chromium has internal web tests / unit tests as well for this feature. *Flag name on about://flags* *No information provided* *Finch feature name* PreserveDropEffect *Rollout plan* Will ship enabled for all users *Requires code in //chrome?* False *Tracking bug* https://issues.chromium.org/issues/40068941 *Estimated milestones* Shipping on desktop146 Shipping on Android146 Shipping on WebView146 *Anticipated spec changes* Open questions about a feature may be a source of future web compat or interop issues. Please list open issues (e.g. links to known github issues in the project for the feature specification) whose resolution may introduce web compat/interop risk (e.g., changing to naming or structure of the API in a non-backward-compatible way). *No information provided* *Link to entry on the Chrome Platform Status* https://chromestatus.com/feature/5140028068069376?gate=6545001561587712 This intent message was generated by Chrome Platform Status <https://chromestatus.com>. -- 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 [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/679e28df-607d-45ed-95ca-beee006f9eb9n%40chromium.org.
