defaults ======== [![CircleCI](https://circleci.com/gh/creasty/defaults/tree/master.svg?style=svg)](https://circleci.com/gh/creasty/defaults/tree/master) [![codecov](https://codecov.io/gh/creasty/defaults/branch/master/graph/badge.svg)](https://codecov.io/gh/creasty/defaults) [![GitHub release](https://img.shields.io/github/release/creasty/defaults.svg)](https://github.com/creasty/defaults/releases) [![License](https://img.shields.io/github/license/creasty/defaults.svg)](./LICENSE) Initialize structs with default values - Supports almost all kind of types - Scalar types - `int/8/16/32/64`, `uint/8/16/32/64`, `float32/64` - `uintptr`, `bool`, `string` - Complex types - `map`, `slice`, `struct` - Nested types - `map[K1]map[K2]Struct`, `[]map[K1]Struct[]` - Aliased types - `time.Duration` - e.g., `type Enum string` - Pointer types - e.g., `*SampleStruct`, `*int` - Recursively initializes fields in a struct - Dynamically sets default values by [`defaults.Setter`](./setter.go) interface - Preserves non-initial values from being reset with a default value Usage ----- ```go type Gender string type Sample struct { Name string `default:"John Smith"` Age int `default:"27"` Gender Gender `default:"m"` Slice []string `default:"[]"` SliceByJSON []int `default:"[1, 2, 3]"` // Supports JSON Map map[string]int `default:"{}"` MapByJSON map[string]int `default:"{\"foo\": 123}"` MapOfStruct map[string]OtherStruct MapOfPtrStruct map[string]*OtherStruct MapOfStructWithTag map[string]OtherStruct `default:"{\"Key1\": {\"Foo\":123}}"` Struct OtherStruct `default:"{}"` StructPtr *OtherStruct `default:"{\"Foo\": 123}"` NoTag OtherStruct // Recurses into a nested struct by default OptOut OtherStruct `default:"-"` // Opt-out } type OtherStruct struct { Hello string `default:"world"` // Tags in a nested struct also work Foo int `default:"-"` Random int `default:"-"` } // SetDefaults implements defaults.Setter interface func (s *OtherStruct) SetDefaults() { if defaults.CanUpdate(s.Random) { // Check if it's a zero value (recommended) s.Random = rand.Int() // Set a dynamic value } } ``` ```go obj := &Sample{} if err := defaults.Set(obj); err != nil { panic(err) } ```