参考文档 && 引用资料

• ZetCode文档
• Pongo2Gin的Gitlab仓库
  • 实现了一个HTML渲染实例，可以把Gin默认的渲染实例替换掉
• Pongo2本体
• Github-Pongo2官方手册
• Github-Pongo2 过滤器文档

---

• 参考文档 && 引用资料
• 须知
  • 模板语句包裹符
• 模板管理
  • 模板加载
  • 模板渲染
• 语法
  • 运算操作
  • 控制结构
  • 函数/过滤器：传送门
• 示例
• 在Gin中使用Pongo2

须知

模板语句包裹符

• {% %} - 语句
• {{ }} - 会被打印到模板中的表达式
• {# #} - 注释
• # ## - 内联语句

模板管理

模板加载

从字符串中加载模板：pongo2.FromString

package main

import (
    "fmt"
    "log"

    "github.com/flosch/pongo2/v5"
)

func main() {

    tpl, err := pongo2.FromString("Hello {{ name }}!")

    if err != nil {
        log.Fatal(err)
    }

    res, err := tpl.Execute(pongo2.Context{"name": "John Doe"})

    if err != nil {
        log.Fatal(err)
    }

    fmt.Println(res)
}

从文件中加载模板：pongo2.FromFile

{{ name }} is a {{ occupation }}

package main

import (
    "fmt"
    "log"

    "github.com/flosch/pongo2/v5"
)

func main() {

    tpl, err := pongo2.FromFile("message.tpl")

    if err != nil {
        log.Fatal(err)
    }

    name, occupation := "John Doe", "gardener"
    ctx := pongo2.Context{"name": name, "occupation": occupation}

    res, err := tpl.Execute(ctx)

    if err != nil {
        log.Fatal(err)
    }

    fmt.Println(res)
}

从字节序列中加载模板：pongo2.FromBytes

从缓存中加载模板：pongo2.FromCache

相关信息

Pongo2Gin仓库文档的一句原文：
“Caching is implemented by the Pongo2 library itself.”

模板渲染

下面这些函数都接受pongo.Context参数作为模板上下文

• Execute
• ExecuteWriter
• ExecuteBytes

语法

运算操作

var (

	// Available symbols in pongo2 (within filters/tag)
	TokenSymbols = []string{

		"{{-", "-}}", "{%-", "-%}",

		"==", ">=", "<=", "&&", "||", "{{", "}}", "{%", "%}", "!=", "<>",

		"(", ")", "+", "-", "*", "<", ">", "/", "^", ",", ".", "!", "|", ":", "=", "%",
	}

	// Available keywords in pongo2
	TokenKeywords = []string{"in", "and", "or", "not", "true", "false", "as", "export"}
)

你知道我要说什么

数学运算

布尔运算

逻辑连接符号

控制结构

if-else结构

{% for todo in todos -%}
    {% if todo.Done %}
        {{- todo.Title -}}
    {% endif %}
{% endfor %}

for结构

{% for word in words -%}
    {{ word }}
{% endfor %}

传送门

length：返回数组、切片、字符串和Map的长度

func (v *Value) Len() int

Len returns the length for an array, chan, map, slice or string. Otherwise it will return 0.

{% for word in words -%}
    {{ word }} has {{ word | length }} characters
{% endfor %}

传送门

自定义过滤器

func RegisterFilter(name string, fn FilterFunction) error

RegisterFilter registers a new filter. If there's already a filter with the same name, RegisterFilter will panic. You usually want to call this function in the filter's init() function: http://golang.org/doc/effective_go.html#init

替换过滤器

func ReplaceFilter(name string, fn FilterFunction) error

ReplaceFilter replaces an already registered filter with a new implementation. Use this function with caution since it allows you to change existing filter behaviour.

示例

在net/http服务器中使用模板

package main

import (
    "net/http"

    "github.com/flosch/pongo2/v5"
)

type User struct {
    Name       string
    Occupation string
}

var tpl = pongo2.Must(pongo2.FromFile("users.html"))

func usersHandler(w http.ResponseWriter, r *http.Request) {

    users := []User{
        {Name: "John Doe", Occupation: "gardener"},
        {Name: "Roger Roe", Occupation: "driver"},
        {Name: "Peter Smith", Occupation: "teacher"},
    }

    err := tpl.ExecuteWriter(pongo2.Context{"users": users}, w)

    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
    }
}

func main() {

    http.HandleFunc("/users", usersHandler)
    http.ListenAndServe(":8080", nil)
}

在Gin中使用Pongo2

可以看看Pongo2Gin

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