Make 'decoder' and 'marshal' public

[chiaradiamarcelo]

The purpose of this PR is to make the 'decoder' and 'marshal' public so they can be extended.

A possible use case is extend the 'decoder' to unmarshal server request and make it possible to integrate the library with different servers, for example. For the same use case, making the 'marshal' function public is enough for encoding a server response.

I work for the Uyuni-project (https://github.com/uyuni-project) and in our side, we are integrating this library with Gorilla RPC(https://github.com/gorilla/rpc) to build an API gateway (https://github.com/uyuni-project/hub-xmlrpc-api).

[icholy]

@chiaradiamarcelo hey thanks for the contribution. Instead of exporting Decoder, wouldn't just exporting Marshal and Unmarshal cover the same use-case?

[chiaradiamarcelo]

@chiaradiamarcelo hey thanks for the contribution. Instead of exporting Decoder, wouldn't just exporting Marshal and Unmarshal cover the same use-case?

Hi @icholy , thanks for the reply.

Exporting 'Unmarshal' is not enough, cause it assumes that only one parameter is contained in the raw XML. I guess it's this way cause it's purpose is to unmarshal a server response, and usually it comes all in one field.
For unmarshalling a server request this has to be extended to be able to decode many parameters instead of only one.

[icholy]

@chiaradiamarcelo I think this change is out of scope for this project. You might want to check out https://github.com/alexejk/go-xmlrpc for another implementation of xmlrpc.