4.自定义io.Writer渲染
最后更新于：2022-04-02 04:46:39
自定义io.Writer渲染
(index.html同模板渲染终端index.html保持不变)
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 main
import (
// "os"
"fmt"
"html/template"
"io"
"net/http"
)
var myTemplate *template.Template
type 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)
p.output += "*"
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:"Murphy",age:"28"}
resultWriter := &Result{}
io.WriteString(resultWriter, "hello world\r\n")
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("./index.html")
http.HandleFunc("/user/info", userInfo)
err := http.ListenAndServe("0.0.0.0:8880", nil)
if err != nil {
fmt.Println("http listen failed")
}
}
~~~
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：
$ go run main.go
~~~
called by template
called by template
called by template
called by template
called by template
called by template
render data: hello world
*
';
hello,*Murphy* *{Murphy 28}*
* ~~~