package middleware
import (
"fmt"
"html/template"
"net/http"
"net/url"
"os"
"path"
"path/filepath"
"strings"
"github.com/labstack/echo"
"github.com/labstack/gommon/bytes"
)
type (
// StaticConfig defines the config for Static middleware.
StaticConfig struct {
// Skipper defines a function to skip middleware.
Skipper Skipper
// Root directory from where the static content is served.
// Required.
Root string `yaml:"root"`
// Index file for serving a directory.
// Optional. Default value "index.html".
Index string `yaml:"index"`
// Enable HTML5 mode by forwarding all not-found requests to root so that
// SPA (single-page application) can handle the routing.
// Optional. Default value false.
HTML5 bool `yaml:"html5"`
// Enable directory browsing.
// Optional. Default value false.
Browse bool `yaml:"browse"`
}
)
const html = `
{{ .Name }}
{{ range .Files }}
-
{{ if .Dir }}
{{ $name := print .Name "/" }}
{{ $name }}
{{ else }}
{{ .Name }}
{{ .Size }}
{{ end }}
{{ end }}
`
var (
// DefaultStaticConfig is the default Static middleware config.
DefaultStaticConfig = StaticConfig{
Skipper: DefaultSkipper,
Index: "index.html",
}
)
// Static returns a Static middleware to serves static content from the provided
// root directory.
func Static(root string) echo.MiddlewareFunc {
c := DefaultStaticConfig
c.Root = root
return StaticWithConfig(c)
}
// StaticWithConfig returns a Static middleware with config.
// See `Static()`.
func StaticWithConfig(config StaticConfig) echo.MiddlewareFunc {
// Defaults
if config.Root == "" {
config.Root = "." // For security we want to restrict to CWD.
}
if config.Skipper == nil {
config.Skipper = DefaultStaticConfig.Skipper
}
if config.Index == "" {
config.Index = DefaultStaticConfig.Index
}
// Index template
t, err := template.New("index").Parse(html)
if err != nil {
panic(fmt.Sprintf("echo: %v", err))
}
return func(next echo.HandlerFunc) echo.HandlerFunc {
return func(c echo.Context) (err error) {
if config.Skipper(c) {
return next(c)
}
p := c.Request().URL.Path
if strings.HasSuffix(c.Path(), "*") { // When serving from a group, e.g. `/static*`.
p = c.Param("*")
}
p, err = url.PathUnescape(p)
if err != nil {
return
}
name := filepath.Join(config.Root, path.Clean("/"+p)) // "/"+ for security
fi, err := os.Stat(name)
if err != nil {
if os.IsNotExist(err) {
if err = next(c); err != nil {
if he, ok := err.(*echo.HTTPError); ok {
if config.HTML5 && he.Code == http.StatusNotFound {
return c.File(filepath.Join(config.Root, config.Index))
}
}
return
}
}
return
}
if fi.IsDir() {
index := filepath.Join(name, config.Index)
fi, err = os.Stat(index)
if err != nil {
if config.Browse {
return listDir(t, name, c.Response())
}
if os.IsNotExist(err) {
return next(c)
}
return
}
return c.File(index)
}
return c.File(name)
}
}
}
func listDir(t *template.Template, name string, res *echo.Response) (err error) {
file, err := os.Open(name)
if err != nil {
return
}
files, err := file.Readdir(-1)
if err != nil {
return
}
// Create directory index
res.Header().Set(echo.HeaderContentType, echo.MIMETextHTMLCharsetUTF8)
data := struct {
Name string
Files []interface{}
}{
Name: name,
}
for _, f := range files {
data.Files = append(data.Files, struct {
Name string
Dir bool
Size string
}{f.Name(), f.IsDir(), bytes.Format(f.Size())})
}
return t.Execute(res, data)
}