Remove a document field before saving in CouchDB?

I'm POSTing a documents to couchdb and I want to remove doc.phone field if that is null before I save.

Is that possible without using _update 开发者_如何学运维handler since I want the request to look like: POST /db

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Unfortunately, validation functions do not allow you to mutate the document. (it can only accept or reject a write)

However, if you are concerned with the url, perhaps you could use an update handler in conjunction with URL Rewrites.