Ability to load files by string or stream

[andrei-dascalu]

This is:

- [ ] a bug report
- [x] a feature request
- [ ] **not** a usage question (ask them on https://stackoverflow.com/questions/tagged/phpspreadsheet or https://gitter.im/PHPOffice/PhpSpreadsheet)

What is the expected behavior?

Allow loading by file content or passing a stream and transfer the load responsibility to the user, perhaps as an alternative to the current "by file" loading.

It would be greatly appreciated.

What is the current behavior?

Currently, in order to load an excel/ods spreadsheet, one needs to provide a full path to a local file. This is inconvenient in a number of situations.

For example, when using a filesystem abstraction that works with cloud storage systems (eg: Flysystem), there is no local file. A workaround can be to make a local copy, work with it and then delete it, but this is inconvenient/risky when using containers that have no local persistence and may have limited to no local storage (consider a long-running service in Kubernetes, you may limit per container storage and exceeding that may break the application).

Which versions of PhpSpreadsheet and PHP are affected?

PHPSpreadsheet: 1.17
PHP: 7.4

[MarkBaker]

I would love to be able to do this, I'd have done it years ago if it was possible. Unfortunately, with the exception of csv files) most spreadsheet format files are non-linear in structure, requiring the data source to be seekable, both forward and backward. While file streams support this, not all streams do.

The best that I believe I could do would be to process the stream data to a temporary file or to a stream that does support seekable, but copying to a seekable stream could be a big memory overhead

[nerdgeneration]

I would also love this feature. The writer will take a file handle, the reader has a bunch of assertFile and path checks. I disagree with the memory overhead when php://temp is an ideal solution to all the above concerns.

[toriqsetiawan]

what is the status of this feature? :)

[MarkBaker]

what is the status of this feature? :)

Unlikely

[lkmorlan]

Using PhpSpreadsheet from Drupal, I found it supports stream wrappers (protocol handlers) for some formats, such as CSV and XLS. But it does not work in XLSX. It throws "Unable to identify a reader for this file".

This appears to be caused by ZipArchive::open() not supporting stream wrappers.

It would be nice to at least get a better error message. The current error makes it sound like the file is the problem.

It might also be an improvement to prevent stream wrappers from working on any formats so that there is consistency. As it is, someone could implement and test on a few formats, everything seems to work fine, and then it breaks when someone uses a different format. However, this would be a breaking change for some users.