Introduction

Serve static files from a specific directory (system physical or embedded to the application) is done by the Party.HandleDir method.

HandleDir registers a handler that serves HTTP requests with the contents of a file system (physical or embedded).

  • First parameter : the route path

  • Second parameter : the file system that needs to be served

  • Third parameter : optional, the directory options.

HandleDir(requestPath string, fs http.FileSystem, opts ...DirOptions) ( []*Route)

The DirOptions structure looks like this:

type DirOptions struct {
// Defaults to "/index.html", if request path is ending with **/*/$IndexName
// then it redirects to **/*(/) which another handler is handling it,
// that another handler, called index handler, is auto-registered by the framework
// if end developer does not managed to handle it by hand.
IndexName string
// PushTargets filenames (map's value) to
// be served without additional client's requests (HTTP/2 Push)
// when a specific request path (map's key WITHOUT prefix)
// is requested and it's not a directory (it's an `IndexFile`).
//
// Example:
// "/": {
// "favicon.ico",
// "js/main.js",
// "css/main.css",
// }
PushTargets map[string][]string
// PushTargetsRegexp like `PushTargets` but accepts regexp which
// is compared against all files under a directory (recursively).
// The `IndexName` should be set.
//
// Example:
// "/": regexp.MustCompile("((.*).js|(.*).css|(.*).ico)$")
// See `iris.MatchCommonAssets` too.
PushTargetsRegexp map[string]*regexp.Regexp
// Cache to enable in-memory cache and pre-compress files.
Cache DirCacheOptions
// When files should served under compression.
Compress bool
// List the files inside the current requested directory if `IndexName` not found.
ShowList bool
// If `ShowList` is true then this function will be used instead
// of the default one to show the list of files of a current requested directory(dir).
// See `DirListRich` package-level function too.
DirList DirListFunc
// Files downloaded and saved locally.
Attachments Attachments
// Optional validator that loops through each requested resource.
AssetValidator func(ctx *context.Context, name string) bool
}

Quick Start

Let's say that you have an ./assets folder near to your executable and you want the files to be served through http://localhost:8080/static/**/* route.

app := iris.New()
app.HandleDir("/static", iris.Dir("./assets"))
app.Listen(":8080")

Now, if you want to embed the static files to be lived inside the executable build in order to not depend on a system directory you can use a tool like go-bindata to convert the files into []byte inside your program. Let's take a quick tutorial on this and how Iris helps to serve those data.

Install go-bindata:

$ go get -u github.com/go-bindata/go-bindata/v3/go-bindata

Navigate to your program directory, that the ./assets subdirectory exists and execute:

$ go-bindata -fs -prefix "assets" ./assets/...

The above creates a generated go file which contains a AssetFile() functions that returns a compatible http.FileSystem you can give to Iris to serve the files.

// [app := iris.New...]
app.HandleDir("/static", AssetFile())

Run your app:

$ go run .

The HandleDir supports all the standards, including content-range, for both physical, embedded and cached directories.

However, if you just need a handler to work with, without register a route, you can use the iris.FileServer package-level function instead.

The FileServer function returns a Handler which serves files from a specific system directory, an embedded one or a memory-cached one.

iris.FileServer(fs http.FileSystem, options DirOptions)

Usage

handler := iris.FileServer(iris.Dir("./assets"), iris.DirOptions {
ShowList: true, Compress: true, IndexName: "index.html",
})

Example

Let's create an application that users can upload one or more files and list them.

Copy-paste the contents of main.go:

package main
import (
"crypto/md5"
"fmt"
"io"
"mime/multipart"
"os"
"strconv"
"strings"
"time"
"github.com/kataras/iris/v12"
)
func init() {
os.Mkdir("./uploads", 0700)
}
func main() {
app := iris.New()
app.RegisterView(iris.HTML("./views", ".html"))
// Serve assets (e.g. javascript, css).
app.HandleDir("/public", iris.Dir("./public"))
app.Get("/", index)
app.Get("/upload", uploadView)
app.Post("/upload", upload)
app.HandleDir("/files", iris.Dir("./uploads"), iris.DirOptions{
Compress: true,
ShowList: true,
})
app.Listen(":8080")
}
func index(ctx iris.Context) {
ctx.Redirect("/upload")
}
func uploadView(ctx iris.Context) {
now := time.Now().Unix()
h := md5.New()
io.WriteString(h, strconv.FormatInt(now, 10))
token := fmt.Sprintf("%x", h.Sum(nil))
ctx.View("upload.html", token)
}
const maxSize = 10 * iris.MB
func upload(ctx iris.Context) {
ctx.SetMaxRequestBodySize(maxSize)
_, err := ctx.UploadFormFiles("./uploads", beforeSave)
if err != nil {
ctx.StopWithError(iris.StatusPayloadTooRage, err)
return
}
ctx.Redirect("/files")
}
func beforeSave(ctx iris.Context, file *multipart.FileHeader) {
ip := ctx.RemoteAddr()
ip = strings.ReplaceAll(ip, ".", "_")
ip = strings.ReplaceAll(ip, ":", "_")
file.Filename = ip + "-" + file.Filename
}

The ./views/upload.html is a simple html form, looks like that:

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Upload Files</title>
</head>
<body>
<form enctype="multipart/form-data" action="/upload" method="POST">
<input type="file" id="upload_files" name="upload_files" multiple />
<input type="hidden" name="token" value="{{.}}" />
<input type="button" value="Upload Using JS" onclick="uploadFiles()" />
<input type="submit" value="Upload by submiting the form" />
</form>
<script type="text/javascript">
function uploadFiles() {
let files = document.getElementById("upload_files").files;
let formData = new FormData();
for (var i = 0; i < files.length; i++) {
formData.append("files[]", files[i]);
}
fetch('/upload',
{
method: "POST",
body: formData
}).
then(data => window.location = "/files").
catch(e => window.alert("upload failed: file too large"));
}
</script>
</body>
</html>