feat: allow reading from and writing to php resource

[darthf1]

Hi!

Thanks for creating this fork. Migration was easy and with the types and additional features its a huge improvement over the original codebase.

I have a feature request; Is it possible to allow reading from and writing to a php resource? At least for CSV, I'm not sure if it's possible for XLSX (and other formats) as well.

I noticed the current CSV Reader already converts the filePath to a resource. Maybe it's as easy as changing

protected function openReader(string $filePath): void

to

protected function openReader(string | resource $filePath): void

and check which parameter type has passed?

As for the CSV Writer, I'm not sure if it is the same case?

final public function openToFile($outputFilePath): void

to

final public function openToFile(string | resource $outputFilePath): void

[Slamdunk]

Hi, may I ask what's your use case?

[darthf1]

Yes ofcourse,

My filesystem is abstracted using Flysystem and I'm making heavy usage of FilesystemReader::readStream and FilesystemWriter::writeStream methods.

If the reader supports streams, I can pass the result of FilesystemReader::readStream directly without additional writes to disk, and vice versa for the writer.

Also, not the least, with Flysystem I can only get the contents of the file and not the path to the file since files do not need to "live" on the current filesystem.

[Slamdunk]

Regarding the Writer, although it should be possible to write to a user-provided stream, it wouldn't work as you expect with Flysystem: FilesystemWriter::writeStream expects an already filled stream, you cannot pass to it a stream that still needs to receive the data. So at least a php://memory intermediate stream would be needed anyway and in my experience that's more of a burden rather than an help.

Regarding the Reader, only the CSV one could achieve your goal as both ODS and XLSX rely on ZipStream::open which doesn't accept a stream.
And I don't like very much to add a feature so specific to a single component.

I have a decent experience with Flysystem, streams and filesystem operations on PHP, and although bypassing the disk entirely seems good in theory I strongly suggest you to rely on physical temporary files for intermediate steps, you'll save yourself a lot of pita.

[darthf1]

And I don't like very much to add a feature so specific to a single component.

I fully agree. It should only be done if possible for all formats.

Thank you for your reply and your advice. I'll close this request for now.