CODEWITHSUNDEEP
goyaml
Pamela Kelly
Pamela Kelly

Reputation: 56

Does Golang Yaml Unmarshal Support accessing nested yaml through struct tags?

I have a simple yaml file with nested values, e.g.

name: pamela
favourites: 
  book: the-lion-the-witch-and-the-wardrobe
  movie: barbie

I can successfully unmarshal that using the gopkg.in/yaml.v2 library into the following struct:

type Person struct {
  Name string `yaml:"name"`
  Favourites *Favourites `yaml:"favourites"`
}

type Favourites struct {
  Book string `yaml:"book"`
  Movie string `yaml:"movie"`
}

Is there a way to flatten the yaml where I don't want to create the struct favourites but write the values of favourite book and movie to top level attributes.

So for example, the below does not work but is there anything like it that would allow me to read nested yaml values like this?

type Person struct {
  Name string `yaml:"name"`
  FavouriteBook `yaml:"favourites.book"`
  FavouriteMovie `yaml:"favourites.movie"`
}

Caveat: I've seen the option of implementing a custom unmarshaller. I'd like to avoid that, so my question is more - does anyone know a yaml library that already supports this?

Upvotes: 0

Views: 378

Answers (2)

flyx
flyx

Reputation: 39768

Embedding the Favourites struct is a possibility:

type Person struct {
    Favourites `yaml:"favourites"`
    Name       string `yaml:"name"`
}

type Favourites struct {
    FavouriteBook  string `yaml:"book"`
    FavouriteMovie string `yaml:"movie"`
}

Then you can do person.FavouriteBook etc.

Upvotes: 0

Jim Wright
Jim Wright

Reputation: 6058

With native Golang Unmarshal I don't believe you can do it without a custom Unmarshaller. That said, gson seems to offer that feature.

Upvotes: 0

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