Access the document in the FileProcessor

[Malusia]

I added the mongoose document to the method call of "save" and "remove" of the FileProcessor, so you can access it and pass it to the StorageProvider.

This is a breaking change for all projects who create an own FileProcessor.

Next step is the modification of the mongoose-crate-localfs. I want to pass the the document to the path function.

In addition I want to add the ability to use a function for the option directory.

Both functions (document and path) should get a optional callback function passed, to support async behavior.

Sorry for my bad english 😝

[achingbrain]

Thanks for the PR. What problem did you encounter that led you to make these changes?

[Malusia]

Hey, I want to store files via mongoose-crate but prefix the file names or target directories by data of the model e.g. the id.

I found out it is possible to add the document to the options when I attach the new file, but I think this no good practise and is not supportet by e.g. mongoose-crate-gm.

model.attach('files', {path: 'path/to/some/file.pdf', doc: model}, function () {})

Further there was a bug in the path function, if I returned a modified path.

schema.plugin(crate, {
    storage: new CrateLocalFS({
        path: function(attachment) {
            // error occurs
            return '/some-new-path/' + path.basename(attachment.path)
        }
    }),
    fields: {
        attachments: {
            array: true
        }
    }
});

The async features are nice to set a filename e.g. in the path function by creating a hash with the content of the file like this

function checksumHelper (str, algorithm, encoding) {
    return crypto
        .createHash(algorithm || 'md5')
        .update(str, 'utf8')
        .digest(encoding || 'hex')
}

schema.plugin(crate, {
    storage: new CrateLocalFS({
        path: function(attachment, respond) {
            fs.readFile(attachment.path', function (err, data) {
                if (err) {
                    return respond(err)
                }

                respond(checksum(data, 'sha1'))
            })
        }
    }),
    fields: {
        attachments: {
            array: true
        }
    }
})

In addition it would solve the issue#10 Custom File Names and the issue#1 Future request use the document id in the path function of mongoose-crate-localfs.

[ivanseidel]

+1 for this

Defining path as a function should allow a flexible way to manage file storing. Such as prefixing it with a tenant id, model id, or even customizing namings for the file name and directory.

This should be merged...