Go筆記-template

參考

• http://gohugo.io/templates/go-templates/

邏輯

條件

Conditionals

if, else, with, or & and provide the framework for handling conditional logic in Go Templates. Like range, each statement is closed with end.

Go Templates treat the following values as false:

• false
• 0
• any array, slice, map, or string of length zero

Example 1: if

{{ if isset .Params "title" }}<h4>{{ index .Params "title" }}</h4>{{ end }}

Example 2: if … else

{{ if isset .Params "alt" }}
    {{ index .Params "alt" }}
{{else}}
    {{ index .Params "caption" }}
{{ end }}

Example 3: and & or

{{ if and (or (isset .Params "title") (isset .Params "caption")) (isset .Params "attr")}}

Example 4: with

An alternative way of writing 「if」 and then referencing the same value is to use 「with」 instead. with rebinds the context . within its scope, and skips the block if the variable is absent.

The first example above could be simplified as:

{{ with .Params.title }}<h4>{{ . }}</h4>{{ end }}

Example 5: if … else if

{{ if isset .Params "alt" }}
    {{ index .Params "alt" }}
{{ else if isset .Params "caption" }}
    {{ index .Params "caption" }}
{{ end }}

遍歷

Example 1: Using Context

{{ range array }}
    {{ . }}
{{ end }}

Example 2: Declaring value variable name

{{range $element := array}}
    {{ $element }}
{{ end }}

Example 2: Declaring key and value variable name

{{range $index, $element := array}}
    {{ $index }}
    {{ $element }}
{{ end }}

結構體

調用結構體的方法獲取值

package main

import (
	"fmt"
	"html/template"
	"log"
	"net/http"
)

type User struct {
	name string
}

func (this *User) GetName() string {
	return this.name
}

func test(w http.ResponseWriter, r *http.Request) {
	user := &User{
		name: "hello world!",
	}
	m := map[string]interface{}{
		"user": user,
	}
	t, err := template.ParseFiles("views/test.tpl")
	if err != nil {
		fmt.Println("parseFiles:", err)
		return
	}
	t.Execute(w, m)
}

func main() {
	http.HandleFunc("/", test)
	err := http.ListenAndServe(":9090", nil)
	if err != nil {
		log.Fatal("listenAndServe:", err)
	}
}

如今map中有一個user對象，想在模板中調用user.GetName()：

<div>
        {{.user.GetName}}
    </div>