Go中基础模板怎么用
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1、html/template创建基础静态模板
package mainimport( "html/template" "log" "os")func main(){ tmpl,err := template.New("go-web").Parse(`Hello World!`)//先创建一个template对象 if err != nil { log.Fatalf("Parse:%v",err)//fatalf格式化字符串,打印错误 } err = tmpl.Execute(os.Stdout,nil) //调用方法Execute,两个参数:目的地,data先等于nil if err != nil{ log.Fatal("Execute: %v", err) }}go run test.go 输出:Hello World!
2、输出动态模板
package mainimport( "html/template" "log" "os")func main(){ tmpl,err := template.New("go-web").Parse(`Hello World!,{{.}}`)//先创建能够根据输入数据的不同,产生不同的效果的动态模板{{}}, "."代表跟对象"go web" if err != nil { log.Fatalf("Parse:%v",err)//fatalf格式化字符串,打印错误 } err = tmpl.Execute(os.Stdout,"go web") //调用方法Execute,两个参数:目的地,data先等于go web,此时跟对象的值是 go web if err != nil{ log.Fatal("Execute: %v", err) }}go run test.go 输出:Hello World!,go webpackage mainimport( "html/template" "log" "os")type Package struct {//自定义的传入类型Package Name string NumFuncs int NumVars int}func main(){ tmpl,err := template.New("go-web").Parse(`Hello World!,{{.}}`)//先创建能够根据输入数据的不同,产生不同的效果的动态模板{{}}, .代表跟对象 if err != nil { log.Fatalf("Parse:%v",err)//fatalf格式化字符串,打印错误 } err = tmpl.Execute(os.Stdout,&Package{ //自定义的传入类型Package Name :"go-web", NumFuncs:12, NumVars:1200, }) //调用方法Execute,两个参数:目的地,data先等于go web,此时跟对象的值是 go web if err != nil{ log.Fatal("Execute: %v", err) }}go run test.go 输出:Hello World!,{go-web 12 1200}如何将模板渲染的结果输出到stdout呢?package mainimport( "html/template" "log" "os")type Package struct { Name string NumFuncs int NumVars int}func main(){ tmpl,err := template.New("go-web").Parse(` Package name: {{.Name}} //通过反射寻找方法,字段或者函数,Name必须公开,必须首字母大写, Number of functions: {{.NumFuncs}} Number of variables: {{.NumVars}} `)//先创建能够根据输入数据的不同,产生不同的效果的动态模板{{}}, .代表跟对象 if err != nil { log.Fatalf("Parse:%v",err)//fatalf格式化字符串,打印错误 } err = tmpl.Execute(os.Stdout,&Package{ Name :"go-web", NumFuncs:12, NumVars:1200, }) //调用方法Execute,两个参数:目的地,data先等于go web,此时跟对象的值是 go web if err != nil{ log.Fatal("Execute: %v", err) }}go run test.go 输出: Package name: go-web Number of functions: 12 Number of variables: 1200
3、模板结果输出到http响应流,通过浏览器访问
package mainimport( "html/template" "log" "net/http" "fmt")type Package struct { Name string NumFuncs int NumVars int}func main(){ http.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) { tmpl,err := template.New("go-web").Parse(` Package name: {{.Name}} Number of functions: {{.NumFuncs}} Number of variables: {{.NumVars}} `)//先创建能够根据输入数据的不同,产生不同的效果的动态模板{{}}, .代表跟对象 if err != nil { fmt.Fprintf(writer,"Parse:%v",err) return } err = tmpl.Execute(writer,&Package{ Name :"go-web", NumFuncs:12, NumVars:1200, }) //调用方法Execute,两个参数:目的地,data先等于go web,此时跟对象的值是 go web if err != nil{ fmt.Fprintf(writer,"Execute:%v",err) return } }) log.Println("Starting Server....") log.Fatal(http.ListenAndServe(":4000",nil))}go run test.go 输出:2018/07/10 10:38:40 Starting Server....
浏览器访问:http://localhost:4000/
4、从文件中读取模板的方法
package mainimport( "html/template" "log" "net/http" "fmt")type Package struct { Name string NumFuncs int NumVars int}func main(){ http.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) { tmpl,err := template.ParseFiles("main.tmpl") if err != nil { fmt.Fprintf(writer,"ParseFiles:%v",err) return } err = tmpl.Execute(writer,&Package{ Name :"go-web", NumFuncs:14, NumVars:1200, }) //调用方法Execute,两个参数:目的地,data先等于go web,此时跟对象的值是 go web if err != nil{ fmt.Fprintf(writer,"Execute:%v",err) return } }) log.Println("Starting Server....") log.Fatal(http.ListenAndServe(":4000",nil))}然后编辑本地main.tmpl文件:➜ test pwd/Users/daixuan/qbox/test➜ test vim main.tmplPackage name: {{.Name}}Number of functions: {{.NumFuncs}}Number of variables: {{.NumVars}}go run test.go 输出:2018/07/10 10:52:56 Starting Server....
浏览器访问:http://localhost:4000/
5、http.request 如何使用模板打印出结构中我们所需要的内容
➜ test vim main.tmplMethod: {{.Method}}package mainimport( "html/template" "log" "net/http" "fmt")type Package struct { Name string NumFuncs int NumVars int}func main(){ http.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) { tmpl,err := template.ParseFiles("main.tmpl") if err != nil { fmt.Fprintf(writer,"ParseFiles:%v",err) return } err = tmpl.Execute(writer,request) //调用方法Execute,两个参数:目的地,data先等于go web,此时跟对象的值是 go web if err != nil{ fmt.Fprintf(writer,"Execute:%v",err) return } }) log.Println("Starting Server....") log.Fatal(http.ListenAndServe(":4000",nil))}go run test.go 输出:2018/07/10 11:01:28 Starting Server....
浏览器访问:http://localhost:4000/ 打印出了Method:GET
修改main.tmplMethod: {{.Method}}URL: {{.URL.Path}}
浏览器访问:http://localhost:4000/ 打印出Path: /
打印User-Agent
修改main.tmplMethod: {{.Method}}Path: {{.URL.Path}}Header: {{.Header.Get "User-Agent"}}package mainimport( "html/template" "log" "net/http" "fmt")type Package struct { Name string NumFuncs int NumVars int}func main(){ http.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) { tmpl,err := template.ParseFiles("main.tmpl") if err != nil { fmt.Fprintf(writer,"ParseFiles:%v",err) return } err = tmpl.Execute(writer,request) //调用方法Execute,两个参数:目的地,data先等于go web,此时跟对象的值是 go web if err != nil{ fmt.Fprintf(writer,"Execute:%v",err) return } }) log.Println("Starting Server....") log.Fatal(http.ListenAndServe(":4000",nil))}go run test.go 输出:2018/07/10 11:10:01 Starting Server....
浏览器访问:http://localhost:4000/
6、创建一个真正的html页面
vim main.htmlGo Web Package info:
浏览器访问:http://localhost:4000/
右键查看网页源代码:view-source:http://localhost:4000/
Go Web Package info:
7、简单应用,根据成绩判断成绩等级是A,B,C.....
首先完成从请求参数中获取成绩score的大小vim main.htmlGo Web {{.}} package mainimport( "html/template" "log" "net/http" "fmt")type Package struct { Name string NumFuncs int NumVars int}func main(){ http.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) { tmpl,err := template.ParseFiles("main.html") if err != nil { fmt.Fprintf(writer,"ParseFiles:%v",err) return } score := request.FormValue("score") err = tmpl.Execute(writer,score) if err != nil{ fmt.Fprintf(writer,"Execute:%v",err) return } }) log.Println("Starting Server....") log.Fatal(http.ListenAndServe(":4000",nil))}go run test.go 输出:2018/07/10 11:33:01 Starting Server....
访问:http://localhost:4000/?score=100
输出100
访问:http://localhost:4000/?score=1
输出1
符合预期
判断score是否存在
vim main.htmlGo Web {{if .}} score is {{.}} {{else}} no score {{end}} vim test.gopackage mainimport("html/template""log""net/http""fmt")type Package struct { Name string NumFuncs int NumVars int}func main(){ http.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) { tmpl,err := template.ParseFiles("main.html") if err != nil { fmt.Fprintf(writer,"ParseFiles:%v",err) return } score := request.FormValue("score") err = tmpl.Execute(writer,score) if err != nil{ fmt.Fprintf(writer,"Execute:%v",err) return } }) log.Println("Starting Server....") log.Fatal(http.ListenAndServe(":4000",nil))}go run test.go 输出:2018/07/10 11:38:10 Starting Server....
访问:http://localhost:4000/?score=100
访问:http://localhost:4000/
对数值进行比较
vim main.htmlGo Web {{if gt . 90}} A {{else if gt . 80}} B {{else if gt . 70}} C {{else if gt . 60}} D {{else}} F {{end}} 报错:Execute:template: main.html:6:13: executing "main.html" at : error calling gt: incompatible types for comparison原因是request.FormValue("score")返回的是string类型,不能与int型90比较修改返回类型vim test.gopackage mainimport("html/template""log""net/http""fmt""strconv")type Package struct { Name string NumFuncs int NumVars int}func main(){ http.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) { tmpl,err := template.ParseFiles("main.html") if err != nil { fmt.Fprintf(writer,"ParseFiles:%v",err) return } score := request.FormValue("score") num, _ := strconv.Atoi(score) err = tmpl.Execute(writer,num) if err != nil{ fmt.Fprintf(writer,"Execute:%v",err) return } }) log.Println("Starting Server....") log.Fatal(http.ListenAndServe(":4000",nil))}go run test.go 输出:2018/07/10 11:53:59 Starting Server....
访问:http://localhost:4000/?score=100 输出A
http://localhost:4000/?score=80 输出C
http://localhost:4000/?score=60 输出F
8、range改变作用域
vim main.htmlGo Web {{range $key,$value := .Header}}Method: {{$.Method}} key: {{$key}}
{{range $value}}
http://localhost:4000/
9、with改变作用域
Go Web {{with .URL}} {{.}} {{.Scheme}} {{.User}} {{.Host}} {{.Path}} {{end}} package mainimport("html/template""log""net/http""fmt")type Package struct { Name string NumFuncs int NumVars int}func main(){ http.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) { tmpl,err := template.ParseFiles("main.html") if err != nil { fmt.Fprintf(writer,"ParseFiles:%v",err) return } err = tmpl.Execute(writer,request) if err != nil{ fmt.Fprintf(writer,"Execute:%v",err) return } }) log.Println("Starting Server....") log.Fatal(http.ListenAndServe(":4000",nil))}go run test.go 输出:
访问:http://localhost:4000/1234?score=80 输出:
/1234?score=80
10、with改变作用域
web中想临时输出一些字符串,字段,怎么办?
维护一个大的结构不方便
将跟对象变成一个key类型为string,值类型为空接口的map,再在map中放入需要传入的所有对象,除此之外,还有一个好处,就是可以把map申明为一个变量,在不同的 Handler中进行传递,在最后响应的这个Handler之前,不断的将map中添加新的内容,最终模板渲染的时候,就可以使用到所有的内容
Go Web {{.Request}} {{.Score}} package mainimport("html/template""log""net/http""fmt")type Package struct { Name string NumFuncs int NumVars int}func main(){ http.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) { tmpl,err := template.ParseFiles("main.html") if err != nil { fmt.Fprintf(writer,"ParseFiles:%v",err) return } err = tmpl.Execute(writer,map[string]interface{}{ "Request": request, "Score": 97, }) if err != nil{ fmt.Fprintf(writer,"Execute:%v",err) return } }) log.Println("Starting Server....") log.Fatal(http.ListenAndServe(":4000",nil))}go run test.go 输出:2018/07/10 12:29:10 Starting Server....
http://localhost:4000/ 输出score=97 和GET方法
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