flat

README

flat

Take a golang map and flatten it or unfatten a map with delimited key.

This work inspired by the nodejs flat package

Method

Flatten

Flatten given map, returns a map one level deep.

in := map[string]interface{}{
    "a": "b",
    "c": map[string]interface{}{
        "d": "e",
        "f": "g",
    },
    "z": [2, 1.4567],
}

out, err := flat.Flatten(in, nil)
// out = map[string]interface{}{
//     "a": "b",
//     "c.d": "e",
//     "c.f": "g",
//     "z.0": 2,
//     "z.1": 1.4567,
// }

Unflatten

Since there is flatten, flat should have unfatten.

in := map[string]interface{}{
    "foo.bar": map[string]interface{}{"t": 123},
    "foo":     map[string]interface{}{"k": 456},
}

out, err := flat.Unflatten(in, nil)
// out = map[string]interface{}{
//     "foo": map[string]interface{}{
//         "bar": map[string]interface{}{
//             "t": 123,
//         },
//         "k": 456,
//     },
// }

Options

Delimiter

Use a custom delimiter for flattening/unflattening your objects. Default value is ..

in := map[string]interface{}{
   "hello": map[string]interface{}{
       "world": map[string]interface{}{
           "again": "good morning",
        }
    },
}

out, err := flat.Flatten(in, &flat.Options{
    Delimiter: ":",
})
// out = map[string]interface{}{
//     "hello:world:again": "good morning",
// }

Safe

When Safe is true, fatten will preserve arrays and their contents. Default Safe value is false.

in := map[string]interface{}{
    "hello": map[string]interface{}{
        "world": []interface{}{
            "one",
            "two",
        }
   },
}

out, err := flat.Flatten(in, &flat.Options{
    Delimiter: ".",
    Safe:      true,
})
// out = map[string]interface{}{
//     "hello.world": []interface{}{"one", "two"},
// }

MaxDepth

MaxDepth is the maximum number of nested objects to flatten. MaxDepth can be any integer number. MaxDepth = 0 means no limit.

Default MaxDepth value is 0.

in := map[string]interface{}{
    "hello": map[string]interface{}{
        "world": []interface{}{
            "again": "good morning",
        }
   },
}

out, err := flat.Flatten(in, &flat.Options{
    Delimiter: ".",
    MaxDepth:  2,
})
// out = map[string]interface{}{
//     "hello.world": map[string]interface{}{"again": "good morning"},
// }

Todos

• Safe option for Unflatten
• Overwrite

Documentation

Overview

Package flat flattens a nested Golang map into a one level deep map. Flat also supports unflatten, turn a one level map into nested one.

You can flatten a Go map

in = map[string]interface{}{
    "foo": map[string]interface{}{
        "bar": map[string]interface{}{
            "t": 123,
        },
        "k": 456,
    },
}

out, err := flat.Flatten(in, nil)
// out = map[string]interface{}{
//     "foo.bar.t": 123,
//     "foo.k": 456,
// }

and a reverse with unflatten

in = map[string]interface{}{
    "foo.bar.t": 123,
    "foo.k": 456,
}
out, err := flat.Unflatten(in, nil)
// out = map[string]interface{}{
//     "foo": map[string]interface{}{
//         "bar": map[string]interface{}{
//             "t": 123,
//         },
//         "k": 456,
//     },
// }

Index

• func Flatten(nested map[string]interface{}, opts *Options) (m map[string]interface{}, err error)
• func Unflatten(flat map[string]interface{}, opts *Options) (nested map[string]interface{}, err error)
• type Options

Functions

func Flatten

func Flatten(nested map[string]interface{}, opts *Options) (m map[string]interface{}, err error)

Flatten the map, it returns a map one level deep regardless of how nested the original map was. By default, the flatten has Delimiter = ".", and no limitation of MaxDepth

func Unflatten

func Unflatten(flat map[string]interface{}, opts *Options) (nested map[string]interface{}, err error)

Unflatten the map, it returns a nested map of a map By default, the flatten has Delimiter = "."

Types

type Options

type Options struct {
	Prefix    string
	Delimiter string
	Safe      bool
	MaxDepth  int
}

Options the flatten options. By default: Delimiter = "."