oxygen is a library designed to create custom formatters like JSON, XML.

oxygen can be installed like any other Go library through go get:

go get github.com/gromey/oxygen

Or, if you are already using Go Modules, you may specify a version number as well:

go get github.com/gromey/oxygen@latest

After you get the library, you must generate your type using the following command:

go run github.com/gromey/oxygen/cmd/generate -n=name

In this command, you must specify a name of your new formatter. The name must contain only letters and be as simple as possible.

This command generates a package with the name specified in the generate command. The package will contain two files asserts.go and tag.go.

WARNING: DO NOT EDIT asserts.go.

tag.go will contain the base implementation of your new formatter. You need to implement three functions Parse, Encode and Decode.

Parse function gets the value of the tag and a pointer to your tag structure, here you need to parse the tag into a tag structure. If you don't use tags, just remove this method.

Encode function receives a value encoded into a byte array, if exists a tag struct and a field name, here you can do additional encoding otherwise just remove this method.

Decode function receives an encoded data, if exists a tag struct and a field name, here you must find a byte array representing a value for the current field and perform initial decoding if necessary before returning this byte array.
You can change the input data and for the next field you will receive the data in a modified form, however this will not affect the original data, since you are working with a copy of the data.