Golang向Templates 插入对象的值

Go对象能够插入到template中，而后把对象的值表如今template中，你能够一层层的分解这个对象，去找他的子字段，当前对象用'.'来表示，因此当当前对象是一个string的时候，你能够用{{.}}。这个包默认使用fmt包来把插入的对象转成string

插入某个对象字段的值，咱们在字段名字前面加上一个'.'前缀就能够了，例如咱们定义一个struct

type Person struct {
        Name      string
        Age       int
        Emails     []string
        Jobs       []*Jobs
}

咱们能够经过

The name is {{.Name}}.
The age is {{.Age}}.

来插入Person对象，Name和Age的值。
咱们能够经过range来遍历一个数组或者其余列表，若是咱们要遍历Person的Email对象，咱们能够

{{range .Emails}}
        ...
{{end}}

上面的Job是这么定义的

type Job struct {
    Employer string
    Role     string
}

咱们想访问Person的job，咱们能够经过{{range .Jobs}}，经过 {{with ...}} ... {{end}} 能够把Jobs切换为当前对象，那么{{.}}就表明的是Jobs

{{with .Jobs}}
    {{range .}}
        An employer is {{.Employer}}
        and the role is {{.Role}}
    {{end}}
{{end}}

你能够用这个来处理任何字段，不单单是数据类型。说了这么多没用的，仍是上代码吧，从代码就能够很清楚的看出tempalte的用法

package main

import (
    "fmt"
    "html/template"
    "os"
)

type Person struct {
    Name   string
    Age    int
    Emails []string
    Jobs   []*Job
}

type Job struct {
    Employer string
    Role     string
}

const templ = `The name is {{.Name}}.
The age is {{.Age}}.
{{range .Emails}}
        An email is {{.}}
{{end}}

{{with .Jobs}}
    {{range .}}
        An employer is {{.Employer}}
        and the role is {{.Role}}
    {{end}}
{{end}}
`

func main() {
    job1 := Job{Employer: "Monash", Role: "Honorary"}
    job2 := Job{Employer: "Box Hill", Role: "Head of HE"}

    person := Person{
        Name:   "jan",
        Age:    50,
        Emails: []string{"jan@newmarch.name", "jan.newmarch@gmail.com"},
        Jobs:   []*Job{&job1, &job2},
    }

    t := template.New("Person template")
    t, err := t.Parse(templ)
    checkError(err)

    err = t.Execute(os.Stdout, person)
    checkError(err)
}

func checkError(err error) {
    if err != nil {
        fmt.Println("Fatal error ", err.Error())
        os.Exit(1)
    }
}

程序输出：

The name is jan.
The age is 50.

        An email is jan@newmarch.name

        An email is jan.newmarch@gmail.com



    
        An employer is Monash
        and the role is Honorary
    
        An employer is Box Hill
        and the role is Head of HE