Sending additional files to Kindle

[Ephemerality]

Hi there,
I'm looking for a bit of plugin advice as I'm unsure as to what the best option might be. I have a standalone application that generates Kindle X-Rays and other misc files. My ultimate goal is to have the "send to device" option also send the .asc files when it sends the book and apnx file (which I now realize is generated within the device driver itself).
I was hoping to simply save them in the same location as the book file but after much fiddling I discovered that the device driver has no method of accessing the original path of the book it is sending, so it is unable to scan for/send any additional files from that path.
My plan B ideas are either:

• Hook into the 'send to device' process before the book is copied to the temp location and save the path somewhere the driver can access (requires no configuration but is messy/unsafe/unreliable?)
• Add a setting to specify the path to the X-Ray Builder output directory and scan/send files from there (is there an option to add a folder-chooser to the plugin preferences dialog?) -- requires minor config, thus less ideal, but if it works it works...

Any thoughts?

Thanks

[kovidgoyal]

There is no really clean solution for this. The device subsystem assumes that book == single file. Changing that would require changes in the guts of calibre's devices subsystem.


The cleanest approach I can come up with is to have your plugin simply add the data to an existing azw3 file as a new record type, XRAY, see for example, the SRCS record in kindlegen produced files. Then the driver can look for this record and extract the info in it into the asc file the kindle needs when sending.

Unfortunately, this will require you to write code to modify existing mobi/azw3 files and add a record to them. That is not exactly trivial.

A more hackish solution is to create an altogether new filetype, say .xray which is basically a zip file containing the original azw3 and the xray information. Then the driver could be modified as before to extract both the xray and the azw3 files during send. The downsides to this are data duplication -- the book will be present twice in the book record and you would also need to write simple wrappers to read/write metadata from the new xray files in calibre.

Regarding your suggestions:

1) Is really not safe since the driver runs in a separate thread from the rest of calibre and is not supposed to be accessing the calibre library at all

2) You can certainly do this, plugins can have arbitrarily complex configuration. But it will be somewhat hard to use for your plugin users.

[Ephemerality]

I was afraid of that. I'd rather not make any changes to users' books but it does seem like the cleanest approach given the limitations of the device driver. The X-Ray files can also be somewhat large (1MB for A Game of Thrones, a 3MB eBook file, uncompressed at least).

I like the concept of your second idea, but the duplication is a definite downside.
I'll have to give it some more thought and decide which would make the most sense.

If I simply go with my second option, is there a generic file-chooser dialog that I can use when I set up my preferences or would I need to create a new dialog class (so the user can select the path to my program)?

Thanks for your input!

[kovidgoyal]

calibre.gui2.choose_files

[Ephemerality]

Excellent, thank you.