验证码中间件

Captcha中间件提供了验证码服务，他是一个 Tango 的插件。

安装

go get github.com/tango-contrib/captcha

示例

package main
import (
    "github.com/lunny/tango"
    "github.com/tango-contrib/captcha"
    "github.com/tango-contrib/renders"
)
type CaptchaAction struct {
    captcha.Captcha
    renders.Renderer
}
func (c *CaptchaAction) Get() error {
    return c.Render("captcha.html", renders.T{
        "captcha": c.CreateHtml(),
    })
}
func (c *CaptchaAction) Post() string {
    if c.Verify() {
        return "true"
    }
    return "false"
}
func main() {
    t := tango.Classic()
    t.Use(captcha.New(), renders.New())
    t.Any("/", new(CaptchaAction))
    t.Run()
}

默认的验证码是保存在内存中，并保留120秒，当然也可以自定义：

package main
import (
    "github.com/lunny/tango"
    "github.com/tango-contrib/cache"
    "github.com/tango-contrib/captcha"
    "github.com/tango-contrib/renders"
)
type CaptchaAction struct {
    captcha.Captcha
    renders.Renderer
}
func (c *CaptchaAction) Get() error {
    return c.Render("captcha.html", renders.T{
        "captcha": c.CreateHtml(),
    })
}
func (c *CaptchaAction) Post() string {
    if c.Verify() {
        return "true"
    }
    return "false"
}
func main() {
      t := tango.Classic()
    c := cache.New(cache.Options{
        Adapter: "memory",
        Interval: 120,
    })
    t.Use(renders.New(), captcha.New(captcha.Options{Caches: c}))
    t.Any("/", new(CaptchaAction))
    t.Run()
}

如果希望使用Redis或者其他来保存，也可以：

package main
import (
    "github.com/lunny/tango"
    "github.com/tango-contrib/cache"
    _ "github.com/tango-contrib/cache-redis"
    "github.com/tango-contrib/captcha"
    "github.com/tango-contrib/renders"
)
type CaptchaAction struct {
    captcha.Captcha
    renders.Renderer
}
func (c *CaptchaAction) Get() error {
    return c.Render("captcha.html", renders.T{
        "captcha": c.CreateHtml(),
    })
}
func (c *CaptchaAction) Post() string {
    if c.Verify() {
        return "true"
    }
    return "false"
}
func main() {
    t := tango.Classic()
    c := cache.New(cache.Options{
        Adapter:       "redis",
        AdapterConfig: "addr=:6379,prefix=cache:",
    })
    t.Use(renders.New(), captcha.New(captcha.Options{Caches: c}))
    t.Any("/", new(CaptchaAction))
    t.Run()
}

Go的模板如下

<!-- templates/captcha.tmpl -->
<form>
{{.captcha}}
</form>

也支持和pongo2渲染中间件一起使用：

package main
import (
    "github.com/lunny/tango"
    "github.com/tango-contrib/captcha"
    "github.com/tango-contrib/tpongo2"
)
type CaptchaAction struct {
    captcha.Captcha
    tpongo2.Renderer
}
func (c *CaptchaAction) Get() error {
    return c.Render("captcha_pongo.html", tpongo2.T{
        "captcha": c.CreateHtml(),
    })
}
func (c *CaptchaAction) Post() string {
    if c.Verify() {
        return "true"
    }
    return "false"
}
func main() {
    t := tango.Classic()
    t.Use(tpongo2.New(), captcha.New())
    t.Any("/", new(CaptchaAction))
    t.Run()
}

Pongo2的模板如下

<!-- templates/captcha.tmpl -->
<form>
{{captcha|safe}}
</form>

选项

captcha.Options 有很多可以选择的配置，当然这些配置都有缺省值：

// ...
t.Use(captcha.New(captcha.Options{
    Caches: cache, // 使用哪种Cache进行验证码数字的存储
    URLPrefix:            "/captcha/",     // URL prefix of getting captcha pictures.
    FieldIdName:        "captcha_id",     // Hidden input element ID.
    FieldCaptchaName:    "captcha",         // User input value element name in request form.
    ChallengeNums:        6,                 // Challenge number.
    Width:                240,            // Captcha image width.
    Height:                80,                // Captcha image height.
    Expiration:            600,             // Captcha expiration time in seconds.
    CachePrefix:        "captcha_",     // Cache key prefix captcha characters.
}))
// ...