File API - where are the missing parts?

These are the existing standardized ways to deal with files locally.

*File API*

Status: Active
Support: Broad, partial,

Covers Blobs (data/mime bags), Blob URLs, Files (name, size, modified),
FileLists, FileReader (reading in blobs and files in different formats).

*HTML5 File Input*

Status: Active
Support: probably good, not tracked.

Allows to get a FileList from an input element

*HTML5 anchor download (and name)*

Status: Active
Support: All except Safari

Allows to pass a blob URL to an anchor element for download.

*What this covers*

   - Read one or many files in their entirety in one go (in python that
   would be open('foobar').read())
   - Save a completed binary string in its entirety in one go to the
   download folder (no overwrite)
   - Listen to file modifications

*What is missing*

   - Read a file incrementally (and with the ability to abort)
   - Save a file incrementally (and with the ability to abort)
   - Overwrite a file (either previously saved or opened)
   - Save as pickable destination
   - Save many files to a user pickable folder
   - Working directory

*Rationales for the missing parts*

It is difficult for web based productivity applications to compete with
native applications in terms of UX/convenience/productivity without the
missing parts.

*Incremental reading*: When dealing with large files that are undesirable
to load into JS memory whole. Current problem is: exceeding JS memory
and/or large delays.

*Incremental writing*: When dealing with writing large files whose content
is undesirable to keep in JS memory whole. When dealing with
computationally intensive data to produce. Current problem is: exceeding JS
memory and/or large delays and/or loosing data, also bad UX (click "prepare
file", click "save").

*Overwriting a file*: When working on content that should be saved to disk
overwriting the existing load/save location. Current problem: all files in
download folder named myfile.txt, myfile (1).txt, myfile (2).txt, myfile
(3).txt, myfile (N).txt etc.

MS Office
[image: Inline image 2]

[image: Inline image 3]

[image: Inline image 4]

*Save as pickable destination*: When wanting to write a file to a
destination that is somewhere else than the download folder. Current
problem is: #1 save #2 go to downloads #3 move file to where it needs to go
#4 repeat

MS Office

*[image: Inline image 5]*

*[image: Inline image 6]*

*[image: Inline image 7]*

*Save many files to a user pickable folder*: Some formats such as Collada
or OBJ refer external files (images). For file collection export/save like
that it is required to write many files in a folder. Current problem: not
possible at all.

*Working directory*: When saving/opening a file in one webapp, and then
using a different webapp. It is hard on the user to always jump around
between folders to open/save a file.


   1. There have been two now abandoned standards that covered some of this
   functionality ( and What are the successor
   standards to these?
   2. If there are no successors, why not?
   3. Are the rationales for the missing parts clear and uncontroversial?

Received on Sunday, 21 February 2016 11:32:59 UTC