example_test.go

package reflectutils_test

import (
	"encoding/json"
	"fmt"

	. "github.com/sunfmin/reflectutils"
)

// By given these structs
func ExampleSet_0init() {
	type Person struct {
		Name        string
		Score       float64
		Gender      int
		Company     *Company
		Departments []*Department
		Projects    []Project
		Phones      map[string]string
		Languages   map[string]Language
	}

	type Language struct {
		Code string
		Name string
	}

	type Company struct {
		Name   string
		Phone  *Phone
		Phone2 **Phone
	}

	type Department struct {
		Id   int
		Name string
	}

	type Project struct {
		Id      string
		Name    string
		Members []*Person
	}

	type Phone struct {
		Number string
	}
}

// For How to set simple field
func ExampleSet_1setfield() {
	var p *Person
	Set(&p, "Name", "Felix")
	Set(&p, "Score", 66.88)
	Set(&p, "Gender", 1)
	printJsonV(p)
	fmt.Println(MustGet(&p, "Score"))
	// Output:
	// {
	// 	"Name": "Felix",
	// 	"Score": 66.88,
	// 	"Gender": 1,
	// 	"Company": null,
	// 	"Departments": null,
	// 	"Projects": null,
	// 	"Phones": null,
	// 	"Languages": null
	// }
	// 66.88
}

// For how to set a struct property
func ExampleSet_2setstructproperty() {
	p := &Person{}
	Set(p, ".Company.Name", "The Plant")
	Set(p, ".Company.Phone.Number", "911")
	printJsonV(p)
	fmt.Println(MustGet(&p, ".Company.Phone.Number"))

	// Output:
	// {
	// 	"Name": "",
	// 	"Score": 0,
	// 	"Gender": 0,
	// 	"Company": {
	// 		"Name": "The Plant",
	// 		"Phone": {
	// 			"Number": "911"
	// 		}
	// 	},
	// 	"Departments": null,
	// 	"Projects": null,
	// 	"Phones": null,
	// 	"Languages": null
	// }
	// 911
}

// For how to set slice and it's property
func ExampleSet_3setsliceproperty() {
	var p *Person
	Set(&p, "Departments[0].Id", 1)
	Set(&p, "Departments[0].Name", "High Tech")
	Set(&p, "Projects[0].Name", "UIBuilder")
	// if you jump the index for an array, It will put nil in between
	// So there will be no index out of range error.
	Set(&p, "Departments[3].Id", 1)
	Set(&p, "Departments[3].Name", "High Tech")
	printJsonV(p)

	fmt.Println(MustGet(&p, "Departments[3].Name"))
	fmt.Println(MustGet(&p, "Departments[4].Name"))
	fmt.Println(MustGet(&p, "Projects[0].Name"))

	// Output:
	// {
	// 	"Name": "",
	// 	"Score": 0,
	// 	"Gender": 0,
	// 	"Company": null,
	// 	"Departments": [
	// 		{
	// 			"Id": 1,
	// 			"Name": "High Tech"
	// 		},
	// 		null,
	// 		null,
	// 		{
	// 			"Id": 1,
	// 			"Name": "High Tech"
	// 		}
	// 	],
	// 	"Projects": [
	// 		{
	// 			"Id": "",
	// 			"Name": "UIBuilder",
	// 			"Members": null
	// 		}
	// 	],
	// 	"Phones": null,
	// 	"Languages": null
	// }
	// High Tech
	// <nil>
	// UIBuilder
}

// For how to set map property
func ExampleSet_4setmapproperty() {
	var p *Person
	Set(&p, "Languages.en_US.Name", "United States")
	Set(&p, "Languages.en_US.Code", "en_US")
	Set(&p, "Languages.zh_CN.Name", "China")
	Set(&p, "Languages.zh_CN.Code", "zh_CN")

	printJsonV(p)
	fmt.Println(MustGet(&p, "Languages.zh_CN.Code"))

	// Output:
	// {
	// 	"Name": "",
	// 	"Score": 0,
	// 	"Gender": 0,
	// 	"Company": null,
	// 	"Departments": null,
	// 	"Projects": null,
	// 	"Phones": null,
	// 	"Languages": {
	// 		"en_US": {
	// 			"Code": "en_US",
	// 			"Name": "United States"
	// 		},
	// 		"zh_CN": {
	// 			"Code": "zh_CN",
	// 			"Name": "China"
	// 		}
	// 	}
	// }
	// zh_CN
}

// You can do whatever deeper you like
func ExampleSet_5setdeeper() {
	var p *Person
	Set(&p, "Projects[0].Members[0].Company.Phone.Number", "911")

	printJsonV(p)
	fmt.Println(MustGet(&p, "Projects[0].Members[0].Company.Phone.Number"))
	// Output:
	// {
	// 	"Name": "",
	// 	"Score": 0,
	// 	"Gender": 0,
	// 	"Company": null,
	// 	"Departments": null,
	// 	"Projects": [
	// 		{
	// 			"Id": "",
	// 			"Name": "",
	// 			"Members": [
	// 				{
	// 					"Name": "",
	// 					"Score": 0,
	// 					"Gender": 0,
	// 					"Company": {
	// 						"Name": "",
	// 						"Phone": {
	// 							"Number": "911"
	// 						}
	// 					},
	// 					"Departments": null,
	// 					"Projects": null,
	// 					"Phones": null,
	// 					"Languages": null
	// 				}
	// 			]
	// 		}
	// 	],
	// 	"Phones": null,
	// 	"Languages": null
	// }
	// 911
}

// A new way to append to an array
func ExampleSet_6appendtoarray() {
	var p *Person
	for i := 1; i < 6; i++ {
		var d *Department
		Set(&d, "Id", i)
		Set(&d, "Name", fmt.Sprintf("Department of Energy %d", i))
		Set(&p, "Departments[]", d)
	}
	printJsonV(p)
	// Output:
	// {
	// 	"Name": "",
	// 	"Score": 0,
	// 	"Gender": 0,
	// 	"Company": null,
	// 	"Departments": [
	// 		{
	// 			"Id": 1,
	// 			"Name": "Department of Energy 1"
	// 		},
	// 		{
	// 			"Id": 2,
	// 			"Name": "Department of Energy 2"
	// 		},
	// 		{
	// 			"Id": 3,
	// 			"Name": "Department of Energy 3"
	// 		},
	// 		{
	// 			"Id": 4,
	// 			"Name": "Department of Energy 4"
	// 		},
	// 		{
	// 			"Id": 5,
	// 			"Name": "Department of Energy 5"
	// 		}
	// 	],
	// 	"Projects": null,
	// 	"Phones": null,
	// 	"Languages": null
	// }
}

// You could also set []byte data to string property, and vice versa.
// And set string value to int, float
func ExampleSet_6byteandstring() {
	type Obj struct {
		ByteProperty     []byte
		StringProperty   string
		IntValue         int
		FloatValue       float64
		IntValueForBytes int
	}
	var o *Obj
	Set(&o, "ByteProperty", "hello")
	Set(&o, "StringProperty", []byte{0x46, 0x65, 0x6c, 0x69, 0x78})
	Set(&o, "IntValue", "22")
	Set(&o, "IntValueForBytes", []byte{0x32, 0x32})
	Set(&o, "FloatValue", "22.88")
	fmt.Println(string(o.ByteProperty))
	fmt.Println(o.StringProperty)
	fmt.Println(o.IntValue)
	fmt.Println(o.FloatValue)
	fmt.Println(o.IntValueForBytes)
	// Output:
	// hello
	// Felix
	// 22
	// 22.88
	// 22

}

// If you set a property that don't exists, it gives you an error.
func ExampleSet_7notexists() {
	var p *Person
	err := Set(&p, "Whatever.Not.Exists", "911")

	fmt.Println(err)
	// Output:
	// no such field
}

// Get Type of a deep nested object
func ExampleSet_8gettype() {
	type Variant struct {
		Name string
	}
	type Product struct {
		Variants []*Variant
		ByCode   map[string]*Variant
	}
	type Obj struct {
		MainProduct *Product
	}

	var o *Obj

	fmt.Println(GetType(o, "MainProduct.Variants[0].Name"))
	fmt.Println(GetType(o, "MainProduct.Variants[0]"))
	fmt.Println(GetType(o, "MainProduct.Variants"))
	fmt.Println(GetType(o, "MainProduct"))
	fmt.Println(GetType(o, "MainProduct.ByCode.abc"))
	fmt.Println(GetType(o, "MainProduct.ByCode"))
	fmt.Println(GetType(o, "x123.ByCode"))
	fmt.Println(GetType(o, "MainProduct.ByCode.abc.NotExist"))
	// Output:
	// string
	// *reflectutils_test.Variant
	// []*reflectutils_test.Variant
	// *reflectutils_test.Product
	// *reflectutils_test.Variant
	// map[string]*reflectutils_test.Variant
	// <nil>
	// <nil>
}

// ForEach slice with any
func ExampleForEach_9_0_normal() {
	var arr = []*Language{
		{"en_US", "United States"},
		{"zh_CN", "China"},
	}

	ForEach(arr, func(v any) {
		ve := v.(*Language)
		fmt.Printf("%s\n", ve.Name)
	})
	// Output:
	// United States
	// China
}

// ForEach slice with correct type
func ExampleForEach_9_1_with_type() {
	var arr = []*Language{
		{"en_US", "United States"},
		{"zh_CN", "China"},
	}

	ForEach(arr, func(v *Language) {
		fmt.Printf("%s\n", v.Name)
	})
	// Output:
	// United States
	// China
}

// ForEach map with any
func ExampleForEach_9_2_map_with_any() {
	var m = map[string]*Language{
		"en_US": {"en_US", "United States"},
		"zh_CN": {"zh_CN", "China"},
	}

	ForEach(m, func(c any, v any) {
		fmt.Printf("%s: %s\n", c.(string), v.(*Language).Name)
	})
	// Output:
	// en_US: United States
	// zh_CN: China
}

// ForEach map with any
func ExampleForEach_9_3_map_with_correct_type() {
	var m = map[string]*Language{
		"en_US": {"en_US", "United States"},
		"zh_CN": {"zh_CN", "China"},
	}

	ForEach(m, func(c string, v *Language) {
		fmt.Printf("%s: %s\n", c, v.Name)
	})
	// Output:
	// en_US: United States
	// zh_CN: China
}

func printJsonV(v interface{}) {
	j, _ := json.MarshalIndent(v, "", "\t")
	fmt.Printf("\n\n%s\n", j)
}