golang基础-模板渲染（终端、浏览器）、渲染输出文件、自定义io.Writer渲染

来源：互联网发布：linux root用户编辑：程序博客网时间：2024/05/23 12:16

- - 模板渲染终端
  - 模板渲染浏览器输出
  - 模板渲染存储文件
  - 自定义ioWriter渲染

模板渲染终端

1）替换 {{.字段名}}

demo.go

package mainimport (    "fmt"    "os"    "text/template")type Person struct {    Name string    age  string}func main() {    t, err := template.ParseFiles("e:/golang/go_pro/src/safly/index.html")    if err != nil {        fmt.Println("parse file err:", err)        return    }    p := Person{Name: "Mary", age: "31"}    if err := t.Execute(os.Stdout, p); err != nil {        fmt.Println("There was an error:", err.Error())    }}

index.html

<html><head>    <title>    </title></head><body>    <p>        <!--p代表当前对象-->        hello,{{.Name}}        {{.}}    </p></body></html>

然后在终端就可以渲染输出如下：

PS E:\golang\go_pro\src\safly> go run demo.go<html><head>    <title>    </title></head><body>    <p>        <!--p代表当前对象-->        hello,Mary        {Mary 31}    </p></body></html>PS E:\golang\go_pro\src\safly>

模板渲染浏览器输出

index.html保持不变

package mainimport (    "fmt"    "html/template"    // "io"    "net/http")var myTemplate *template.Templatetype Person struct {    Name string    age  string}func userInfo(w http.ResponseWriter,r *http.Request) {    p := Person{Name:"safly",age:"30"}    myTemplate.Execute(w,p)}func initTemplate(fileName string) (err error){    myTemplate,err  = template.ParseFiles(fileName)    if err != nil{        fmt.Println("parse file err:",err)        return    }    return}/*func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {    DefaultServeMux.HandleFunc(pattern, handler)}*/func main() {    initTemplate("e:/golang/go_pro/src/safly/index.html")    http.HandleFunc("/user/info", userInfo)    err := http.ListenAndServe("0.0.0.0:8880", nil)    if err != nil {        fmt.Println("http listen failed")    }}

这里写图片描述

模板渲染存储文件

这里写图片描述

package mainimport (    "os"    "fmt"    "html/template"    // "io"    "net/http")var myTemplate *template.Templatetype Person struct {    Name string    age  string}func userInfo(w http.ResponseWriter,r *http.Request) {    p := Person{Name:"safly",age:"30"}    myTemplate.Execute(os.Stdout,p)    file,err := os.OpenFile("demo.dat", os.O_CREATE|os.O_WRONLY, 0755)    if err != nil {        fmt.Println("open failed err:", err)        return    }    myTemplate.Execute(file,p)}func initTemplate(fileName string) (err error){    myTemplate,err  = template.ParseFiles(fileName)    if err != nil{        fmt.Println("parse file err:",err)        return    }    return}/*func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {    DefaultServeMux.HandleFunc(pattern, handler)}*/func main() {    initTemplate("e:/golang/go_pro/src/safly/index.html")    http.HandleFunc("/user/info", userInfo)    err := http.ListenAndServe("0.0.0.0:8880", nil)    if err != nil {        fmt.Println("http listen failed")    }}

然后demo.dat就被渲染输出内容了：

这里写图片描述

自定义io.Writer渲染

我们看下myTemplate.Execute源码

func (t *Template) Execute(wr io.Writer, data interface{}) error {    if err := t.escape(); err != nil {        return err    }    return t.text.Execute(wr, data)}

type Writer interface {    Write(p []byte) (n int, err error)}

所以我们实现Writer接口方法Write就可以自定义了

package mainimport (    // "os"    "fmt"    "html/template"    "io"    "net/http")var myTemplate *template.Templatetype Person struct {    Name string    age  string}type Result struct {    output string}/*自定义实现接口type Writer interface {    Write(p []byte) (n int, err error)}*/func (p *Result) Write(b []byte) (n int, err error) {    fmt.Println("called by template")    p.output += string(b)    return len(b), nil}/*func WriteString(w Writer, s string) (n int, err error) {    if sw, ok := w.(stringWriter); ok {        return sw.WriteString(s)    }    return w.Write([]byte(s))}*/func userInfo(w http.ResponseWriter,r *http.Request) {    p := Person{Name:"safly",age:"30"}    resultWriter := &Result{}    io.WriteString(resultWriter, "hello world")    myTemplate.Execute(resultWriter,p)    fmt.Println("render data:",resultWriter.output)}func initTemplate(fileName string) (err error){    myTemplate,err  = template.ParseFiles(fileName)    if err != nil{        fmt.Println("parse file err:",err)        return    }    return}/*func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {    DefaultServeMux.HandleFunc(pattern, handler)}*/func main() {    initTemplate("e:/golang/go_pro/src/safly/index.html")    http.HandleFunc("/user/info", userInfo)    err := http.ListenAndServe("0.0.0.0:8880", nil)    if err != nil {        fmt.Println("http listen failed")    }}

我们在浏览器中输入http://localhost:8880/user/info
然后在终端就会渲染出如下内容：

PS E:\golang\go_pro\src\safly> go run demo.gocalled by templatecalled by templatecalled by templatecalled by templatecalled by templatecalled by templaterender data: hello world<html><head>    <title>    </title></head><body>    <p>        hello,safly        {safly 30}    </p></body></html>

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