/*
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* jQuery File Upload Plugin GAE Go Example 3.1.0
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* https://github.com/blueimp/jQuery-File-Upload
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*
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* Copyright 2011, Sebastian Tschan
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* https://blueimp.net
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*
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* Licensed under the MIT license:
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* http://www.opensource.org/licenses/MIT
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*/
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package app
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import (
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"appengine"
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"appengine/blobstore"
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"appengine/image"
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"appengine/taskqueue"
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"bytes"
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"encoding/json"
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"fmt"
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"io"
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"log"
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"mime/multipart"
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"net/http"
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"net/url"
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"regexp"
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"strings"
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"time"
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)
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const (
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WEBSITE = "http://blueimp.github.io/jQuery-File-Upload/"
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MIN_FILE_SIZE = 1 // bytes
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MAX_FILE_SIZE = 5000000 // bytes
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IMAGE_TYPES = "image/(gif|p?jpeg|(x-)?png)"
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ACCEPT_FILE_TYPES = IMAGE_TYPES
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EXPIRATION_TIME = 300 // seconds
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THUMBNAIL_PARAM = "=s80"
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)
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var (
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imageTypes = regexp.MustCompile(IMAGE_TYPES)
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acceptFileTypes = regexp.MustCompile(ACCEPT_FILE_TYPES)
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)
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type FileInfo struct {
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Key appengine.BlobKey `json:"-"`
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Url string `json:"url,omitempty"`
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ThumbnailUrl string `json:"thumbnailUrl,omitempty"`
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Name string `json:"name"`
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Type string `json:"type"`
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Size int64 `json:"size"`
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Error string `json:"error,omitempty"`
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DeleteUrl string `json:"deleteUrl,omitempty"`
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DeleteType string `json:"deleteType,omitempty"`
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}
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func (fi *FileInfo) ValidateType() (valid bool) {
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if acceptFileTypes.MatchString(fi.Type) {
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return true
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}
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fi.Error = "Filetype not allowed"
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return false
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}
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func (fi *FileInfo) ValidateSize() (valid bool) {
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if fi.Size < MIN_FILE_SIZE {
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fi.Error = "File is too small"
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} else if fi.Size > MAX_FILE_SIZE {
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fi.Error = "File is too big"
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} else {
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return true
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}
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return false
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}
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func (fi *FileInfo) CreateUrls(r *http.Request, c appengine.Context) {
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u := &url.URL{
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Scheme: r.URL.Scheme,
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Host: appengine.DefaultVersionHostname(c),
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Path: "/",
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}
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uString := u.String()
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fi.Url = uString + escape(string(fi.Key)) + "/" +
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escape(string(fi.Name))
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fi.DeleteUrl = fi.Url + "?delete=true"
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fi.DeleteType = "DELETE"
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if imageTypes.MatchString(fi.Type) {
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servingUrl, err := image.ServingURL(
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c,
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fi.Key,
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&image.ServingURLOptions{
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Secure: strings.HasSuffix(u.Scheme, "s"),
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Size: 0,
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Crop: false,
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},
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)
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check(err)
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fi.ThumbnailUrl = servingUrl.String() + THUMBNAIL_PARAM
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}
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}
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func check(err error) {
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if err != nil {
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panic(err)
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}
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}
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func escape(s string) string {
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return strings.Replace(url.QueryEscape(s), "+", "%20", -1)
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}
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func delayedDelete(c appengine.Context, fi *FileInfo) {
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if key := string(fi.Key); key != "" {
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task := &taskqueue.Task{
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Path: "/" + escape(key) + "/-",
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Method: "DELETE",
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Delay: time.Duration(EXPIRATION_TIME) * time.Second,
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}
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taskqueue.Add(c, task, "")
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}
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}
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func handleUpload(r *http.Request, p *multipart.Part) (fi *FileInfo) {
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fi = &FileInfo{
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Name: p.FileName(),
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Type: p.Header.Get("Content-Type"),
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}
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if !fi.ValidateType() {
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return
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}
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defer func() {
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if rec := recover(); rec != nil {
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log.Println(rec)
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fi.Error = rec.(error).Error()
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}
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}()
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lr := &io.LimitedReader{R: p, N: MAX_FILE_SIZE + 1}
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context := appengine.NewContext(r)
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w, err := blobstore.Create(context, fi.Type)
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defer func() {
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w.Close()
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fi.Size = MAX_FILE_SIZE + 1 - lr.N
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fi.Key, err = w.Key()
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check(err)
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if !fi.ValidateSize() {
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err := blobstore.Delete(context, fi.Key)
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check(err)
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return
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}
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delayedDelete(context, fi)
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fi.CreateUrls(r, context)
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}()
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check(err)
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_, err = io.Copy(w, lr)
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return
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}
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func getFormValue(p *multipart.Part) string {
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var b bytes.Buffer
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io.CopyN(&b, p, int64(1<<20)) // Copy max: 1 MiB
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return b.String()
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}
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func handleUploads(r *http.Request) (fileInfos []*FileInfo) {
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fileInfos = make([]*FileInfo, 0)
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mr, err := r.MultipartReader()
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check(err)
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r.Form, err = url.ParseQuery(r.URL.RawQuery)
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check(err)
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part, err := mr.NextPart()
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for err == nil {
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if name := part.FormName(); name != "" {
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if part.FileName() != "" {
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fileInfos = append(fileInfos, handleUpload(r, part))
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} else {
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r.Form[name] = append(r.Form[name], getFormValue(part))
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}
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}
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part, err = mr.NextPart()
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}
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return
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}
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func get(w http.ResponseWriter, r *http.Request) {
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if r.URL.Path == "/" {
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http.Redirect(w, r, WEBSITE, http.StatusFound)
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return
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}
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parts := strings.Split(r.URL.Path, "/")
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if len(parts) == 3 {
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if key := parts[1]; key != "" {
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blobKey := appengine.BlobKey(key)
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bi, err := blobstore.Stat(appengine.NewContext(r), blobKey)
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if err == nil {
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w.Header().Add("X-Content-Type-Options", "nosniff")
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if !imageTypes.MatchString(bi.ContentType) {
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w.Header().Add("Content-Type", "application/octet-stream")
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w.Header().Add(
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"Content-Disposition",
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fmt.Sprintf("attachment; filename=\"%s\"", parts[2]),
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)
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}
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w.Header().Add(
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"Cache-Control",
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fmt.Sprintf("public,max-age=%d", EXPIRATION_TIME),
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)
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blobstore.Send(w, blobKey)
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return
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}
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}
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}
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http.Error(w, "404 Not Found", http.StatusNotFound)
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}
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func post(w http.ResponseWriter, r *http.Request) {
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result := make(map[string][]*FileInfo, 1)
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result["files"] = handleUploads(r)
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b, err := json.Marshal(result)
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check(err)
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if redirect := r.FormValue("redirect"); redirect != "" {
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if strings.Contains(redirect, "%s") {
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redirect = fmt.Sprintf(
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redirect,
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escape(string(b)),
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)
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}
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http.Redirect(w, r, redirect, http.StatusFound)
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return
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}
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w.Header().Set("Cache-Control", "no-cache")
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jsonType := "application/json"
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if strings.Index(r.Header.Get("Accept"), jsonType) != -1 {
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w.Header().Set("Content-Type", jsonType)
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}
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fmt.Fprintln(w, string(b))
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}
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func delete(w http.ResponseWriter, r *http.Request) {
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parts := strings.Split(r.URL.Path, "/")
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if len(parts) != 3 {
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return
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}
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if key := parts[1]; key != "" {
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c := appengine.NewContext(r)
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blobKey := appengine.BlobKey(key)
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err := blobstore.Delete(c, blobKey)
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check(err)
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err = image.DeleteServingURL(c, blobKey)
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check(err)
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}
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}
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func handle(w http.ResponseWriter, r *http.Request) {
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params, err := url.ParseQuery(r.URL.RawQuery)
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check(err)
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w.Header().Add("Access-Control-Allow-Origin", "*")
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w.Header().Add(
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"Access-Control-Allow-Methods",
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"OPTIONS, HEAD, GET, POST, PUT, DELETE",
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)
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w.Header().Add(
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"Access-Control-Allow-Headers",
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"Content-Type, Content-Range, Content-Disposition",
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)
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switch r.Method {
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case "OPTIONS":
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case "HEAD":
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case "GET":
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get(w, r)
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case "POST":
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if len(params["_method"]) > 0 && params["_method"][0] == "DELETE" {
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delete(w, r)
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} else {
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post(w, r)
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}
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case "DELETE":
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delete(w, r)
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default:
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http.Error(w, "501 Not Implemented", http.StatusNotImplemented)
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}
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}
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func init() {
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http.HandleFunc("/", handle)
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}
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