Allow `createObjectURL` to retain filename from `File` (and similar) objects

What problem are you trying to solve?

We have a datastore that requires authentication to retrieve files (e.g. PDF, CSV, ZIP, PNG, or some Office suite file format) -- it has a file name, a content type, and data. We'd like to allow users to click a link (or button/...) and have the "file" corresponding to that data (which we currently retrieve in a Blob) open in their browser (or download depending on how the browser is feeling) and if at some point the browser decides to save the file (e.g. because the user asks to save a file, or because it doesn't have an internal handler) then we'd like it to favor our proposed filename instead of a blob id.

What solutions exist today?

1. We can construct a Blob or a File w/ a Blob and call createObjectURL with it.
2. We can create an anchor a with a#download with the href set the the url from createObjectURL such that users can click the anchor to get our suggested filename.
3. We can add an iframe containing our blob url

Fwiw, Microsoft had an msSaveBlob which included a defaultName field...

How would you solve it?

Change the specification for createObjectURL so that for objects that have a name (e.g. File), browsers should prefer that name over the blob when saving.

Lesen Sie zunächst die File API-Spezifikation rund um den Einstiegspunkt createObjectURL sowie die Definitionen von File, Blob und object URLs. Ermitteln Sie, wie ein vorgeschlagener Dateiname mit dem Speicherverhalten interagieren sollte, und aktualisieren Sie anschließend die Spezifikation, um diese Präferenz zu definieren, und fügen Sie Konformitätsabdeckung hinzu oder passen Sie sie an, falls die Spezifikation eine relevante Teststelle identifiziert.