golang template

傷城~ 2022-06-08 09:41 192阅读 0赞

**关键内容:**

{ { .}} 表示当前对象 --直接输出对象 便利店数组 map 数据切片 { { range …}}{ { end}} { { with …}}…{ { end}} package main import ( "html/template" "os" ) type Friend struct { Fname string } type Person struct { UserName string Emails []string Friends []*Friend } func main() { f1 := Friend{Fname: "xiaomig"} f2 := Friend{Fname: "xiaowei"} t := template.New("fieldname example") t, _ = t.Parse(`hello { { .UserName}}! { { range .Emails}} an email { { .}} { { end}} { { with .Friends}} { { range .}} my friend name is { { .Fname}} { { end}} { { end}} `) p := Person{UserName: "Astaxie", Emails: []string{"qinzhao@qinzhao.com", "qinzhao@qinzhaocom1"}, Friends: []*Friend{&f1, &f2}} t.Execute(os.Stdout, p) }

**条件处理**  
if-else语法  
如果if else

package main
    
    import (
        "os"
        "text/template"
    )
    
    func main() {
        tEmpty := template.New("template test")
        tEmpty = template.Must(tEmpty.Parse("空 pipeline if demo: { {if ``}} 不会输出. { {end}}\n"))
        tEmpty.Execute(os.Stdout, nil)
    
        tWithValue := template.New("template test")
        tWithValue = template.Must(tWithValue.Parse("不为空的 pipeline if demo: { {if `anything`}} 我有内容，我会输出. { {end}}\n"))
        tWithValue.Execute(os.Stdout, nil)
    
        tIfElse := template.New("template test")
        tIfElse = template.Must(tIfElse.Parse("if-else demo: { {if `anything`}} if部分 { {else}} else部分.{ {end}}\n"))
        tIfElse.Execute(os.Stdout, nil)
    }
    *if里面只能是bool值

**pipelines**

{ { . | html}}

***模板变量***

$var := piple package main import ( "text/template" "fmt" "os" ) func main() { data:=`{ { with $x := "qinzhao" | printf "%q"}}{ {$x}}{ { end}} { { with $x := "output"}}{ { printf "%q" $x}}{ { end}} { { with $x := "output"}}{ {$x | printf "%q"}}{ { end}}` t:=template.New("demo04") tpl,err:=t.Parse(data) if err!=nil{ fmt.Printf("template parse failed %#v \n",err) return } tpl.Execute(os.Stdout,nil) println() }

**模板函数**

package main
    
    import (
        "fmt"
        "html/template"
        "os"
        "strings"
    )
    
    type Friend struct {
        Fname string
    }
    
    type Person struct {
        UserName string
        Emails   []string
        Friends  []*Friend
    }
    
    func EmailDealWith(args ...interface{}) string {
        ok := false
        var s string
        if len(args) == 1 {
            s, ok = args[0].(string)
        }
        if !ok {
            s = fmt.Sprint(args...)
        }
        // find the @ symbol
        substrs := strings.Split(s, "@")
        if len(substrs) != 2 {
            return s
        }
        // replace the @ by " at "
        return (substrs[0] + " at " + substrs[1])
    }
    
    func main() {
        f1 := Friend{Fname: "xiaoming"}
        f2 := Friend{Fname: "hello"}
        t := template.New("fieldname example")
        t = t.Funcs(template.FuncMap{
       "emailDeal": EmailDealWith})
        t, _ = t.Parse(`hello { {.UserName}}! { {$var:=.Emails | len}} { {$var}} { {range .Emails}} an emails { {.|emailDeal}} { {end}} { {with .Friends}} { {range .}} my friend name is { {.Fname}} { {end}} { {end}} `)
        p := Person{UserName: "qinzhao",
            Emails:  []string{
       "qinzhao@ww.com", "qinzhao@ww.com01"},
            Friends: []*Friend{&f1, &f2}}
        t.Execute(os.Stdout, p)
        println()
    }

**模板包内部已经有内置的实现函数**

var builtins = FuncMap{
        "and":      and,
        "call":     call,
        "html":     HTMLEscaper,
        "index":    index,
        "js":       JSEscaper,
        "len":      length,
        "not":      not,
        "or":       or,
        "print":    fmt.Sprint,
        "printf":   fmt.Sprintf,
        "println":  fmt.Sprintln,
        "urlquery": URLQueryEscaper,
    }

**Must操作**

package main
    
    import (
        "fmt"
        "text/template"
    )
    
    func main() {
        tOk := template.New("first")
        template.Must(tOk.Parse(" some static text /* and a comment */"))
        fmt.Println("The first one parsed OK.")
    
        template.Must(template.New("second").Parse("some static text { { .Name }}"))
        fmt.Println("The second one parsed OK.")
    
        fmt.Println("The next one ought to fail.")
        tErr := template.New("check parse error with Must")
        template.Must(tErr.Parse(" some static text { { .Name }}"))
    }

**嵌套模板**

{ { define "子模板名称"}}内容{ { end}} 通过如下方式来调用 { { template "子模板名称"}} //header.tmpl { { define "header"}} <html> <head> <title>演示信息</title> </head> <body> { { end}} //content.tmpl { { define "content"}} { { template "header"}} <h1>演示嵌套</h1> <ul> <li>嵌套使用define定义子模板</li> <li>调用使用template</li> </ul> { { template "footer"}} { { end}} //footer.tmpl { { define "footer"}} </body> </html> { { end}}

package main
    
    import (
        "fmt"
        "os"
        "text/template"
    )
    
    func main() {
        s1, _ := template.ParseFiles("header.html", "content.html", "footer.html")
        s1.ExecuteTemplate(os.Stdout, "header", nil)
        fmt.Println()
        s1.ExecuteTemplate(os.Stdout, "content", nil)
        fmt.Println()
        s1.ExecuteTemplate(os.Stdout, "footer", nil)
        fmt.Println()
        s1.Execute(os.Stdout, nil)
        println()
    }

else

eq
        Returns the boolean truth of arg1 == arg2
    ne
        Returns the boolean truth of arg1 != arg2
    lt
        Returns the boolean truth of arg1 < arg2
    le
        Returns the boolean truth of arg1 <= arg2
    gt
        Returns the boolean truth of arg1 > arg2
    ge
        Returns the boolean truth of arg1 >= arg2