| package mapstructure |
| |
| import ( |
| "fmt" |
| ) |
| |
| func ExampleDecode() { |
| type Person struct { |
| Name string |
| Age int |
| Emails []string |
| Extra map[string]string |
| } |
| |
| // This input can come from anywhere, but typically comes from |
| // something like decoding JSON where we're not quite sure of the |
| // struct initially. |
| input := map[string]interface{}{ |
| "name": "Mitchell", |
| "age": 91, |
| "emails": []string{"one", "two", "three"}, |
| "extra": map[string]string{ |
| "twitter": "mitchellh", |
| }, |
| } |
| |
| var result Person |
| err := Decode(input, &result) |
| if err != nil { |
| panic(err) |
| } |
| |
| fmt.Printf("%#v", result) |
| // Output: |
| // mapstructure.Person{Name:"Mitchell", Age:91, Emails:[]string{"one", "two", "three"}, Extra:map[string]string{"twitter":"mitchellh"}} |
| } |
| |
| func ExampleDecode_errors() { |
| type Person struct { |
| Name string |
| Age int |
| Emails []string |
| Extra map[string]string |
| } |
| |
| // This input can come from anywhere, but typically comes from |
| // something like decoding JSON where we're not quite sure of the |
| // struct initially. |
| input := map[string]interface{}{ |
| "name": 123, |
| "age": "bad value", |
| "emails": []int{1, 2, 3}, |
| } |
| |
| var result Person |
| err := Decode(input, &result) |
| if err == nil { |
| panic("should have an error") |
| } |
| |
| fmt.Println(err.Error()) |
| // Output: |
| // 5 error(s) decoding: |
| // |
| // * 'Age' expected type 'int', got unconvertible type 'string' |
| // * 'Emails[0]' expected type 'string', got unconvertible type 'int' |
| // * 'Emails[1]' expected type 'string', got unconvertible type 'int' |
| // * 'Emails[2]' expected type 'string', got unconvertible type 'int' |
| // * 'Name' expected type 'string', got unconvertible type 'int' |
| } |
| |
| func ExampleDecode_metadata() { |
| type Person struct { |
| Name string |
| Age int |
| } |
| |
| // This input can come from anywhere, but typically comes from |
| // something like decoding JSON where we're not quite sure of the |
| // struct initially. |
| input := map[string]interface{}{ |
| "name": "Mitchell", |
| "age": 91, |
| "email": "foo@bar.com", |
| } |
| |
| // For metadata, we make a more advanced DecoderConfig so we can |
| // more finely configure the decoder that is used. In this case, we |
| // just tell the decoder we want to track metadata. |
| var md Metadata |
| var result Person |
| config := &DecoderConfig{ |
| Metadata: &md, |
| Result: &result, |
| } |
| |
| decoder, err := NewDecoder(config) |
| if err != nil { |
| panic(err) |
| } |
| |
| if err := decoder.Decode(input); err != nil { |
| panic(err) |
| } |
| |
| fmt.Printf("Unused keys: %#v", md.Unused) |
| // Output: |
| // Unused keys: []string{"email"} |
| } |
| |
| func ExampleDecode_weaklyTypedInput() { |
| type Person struct { |
| Name string |
| Age int |
| Emails []string |
| } |
| |
| // This input can come from anywhere, but typically comes from |
| // something like decoding JSON, generated by a weakly typed language |
| // such as PHP. |
| input := map[string]interface{}{ |
| "name": 123, // number => string |
| "age": "42", // string => number |
| "emails": map[string]interface{}{}, // empty map => empty array |
| } |
| |
| var result Person |
| config := &DecoderConfig{ |
| WeaklyTypedInput: true, |
| Result: &result, |
| } |
| |
| decoder, err := NewDecoder(config) |
| if err != nil { |
| panic(err) |
| } |
| |
| err = decoder.Decode(input) |
| if err != nil { |
| panic(err) |
| } |
| |
| fmt.Printf("%#v", result) |
| // Output: mapstructure.Person{Name:"123", Age:42, Emails:[]string{}} |
| } |
| |
| func ExampleDecode_tags() { |
| // Note that the mapstructure tags defined in the struct type |
| // can indicate which fields the values are mapped to. |
| type Person struct { |
| Name string `mapstructure:"person_name"` |
| Age int `mapstructure:"person_age"` |
| } |
| |
| input := map[string]interface{}{ |
| "person_name": "Mitchell", |
| "person_age": 91, |
| } |
| |
| var result Person |
| err := Decode(input, &result) |
| if err != nil { |
| panic(err) |
| } |
| |
| fmt.Printf("%#v", result) |
| // Output: |
| // mapstructure.Person{Name:"Mitchell", Age:91} |
| } |
| |
| func ExampleDecode_embeddedStruct() { |
| // Squashing multiple embedded structs is allowed using the squash tag. |
| // This is demonstrated by creating a composite struct of multiple types |
| // and decoding into it. In this case, a person can carry with it both |
| // a Family and a Location, as well as their own FirstName. |
| type Family struct { |
| LastName string |
| } |
| type Location struct { |
| City string |
| } |
| type Person struct { |
| Family `mapstructure:",squash"` |
| Location `mapstructure:",squash"` |
| FirstName string |
| } |
| |
| input := map[string]interface{}{ |
| "FirstName": "Mitchell", |
| "LastName": "Hashimoto", |
| "City": "San Francisco", |
| } |
| |
| var result Person |
| err := Decode(input, &result) |
| if err != nil { |
| panic(err) |
| } |
| |
| fmt.Printf("%s %s, %s", result.FirstName, result.LastName, result.City) |
| // Output: |
| // Mitchell Hashimoto, San Francisco |
| } |