我无法重定向到main.demo。在重定向没有发生之后，一切正常，直到数据上传。为什么呢？
编辑：app.py
from flask import Blueprint
main = Blueprint('main', __name__)
import json
import os
from flask import Flask, request,render_template,url_for,redirect
from werkzeug import secure_filename
import glob2
from uuid import uuid4
@main.route('/')
def index():
"""Main index page """
return render_template('index.html')
@main.route('/upload', methods=["GET","POST"])
def upload():
if request.method == 'POST':
form = request.form
# Create a unique "session ID" for this particular batch of uploads.
upload_key = str(uuid4())
# Is the upload using Ajax, or a direct POST by the form?
is_ajax = False
if form.get("__ajax", None) == "true":
is_ajax = True
# Target folder for these uploads.
target = "upload/{}".format(upload_key)
try:
os.mkdir(target)
except:
if is_ajax:
return ajax_response(False, "Couldn't create upload directory: {}".format(target))
else:
return "Couldn't create upload directory: {}".format(target)
print "=== Form Data ==="
for key, value in form.items():
print key, "=>", value
for upload in request.files.getlist("file"):
filename = upload.filename.rsplit("/")[0]
destination = "/".join([target, filename])
print "Accept incoming file:", filename
print "Save it to:", destination
upload.save(destination)
return redirect(url_for("main.demo"))
return render_template("upload.html")
@main.route('/demo',methods=["GET","POST"])
def demo():
if request.method == "GET":
return render_template("demo.html")
def ajax_response(status, msg):
status_code = "ok" if status else "error"
return json.dumps(dict(
status=status_code,
msg=msg,
))
def create_app():
global app
app = Flask(__name__,template_folder=os.path.join(os.path.dirname(os.path.abspath(__file__)),'templates'))
app.debug = True
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
app.register_blueprint(main)
#app.config['MAX_CONTENT_LENGTH'] = 16 * 1024 * 1024
return app
以下是我得到的一些日志：
=== Form Data ===
__ajax => true
Accept incoming file: demo.txt
Save it to: upload/XXXXXXX-XXXXXX-XXXXX-XXXXXXX/demo.txt
"POST /upload HTTP/1.1" 302 231 "http://localhost:5000/upload"
"GET /demo HTTP/1.1" 200 3624 "http://localhost:5000/upload"
它表明它正在进行演示，但最终的网址是错误的。为什么会那样？
编辑1：
是否因为页面无法刷新而无法提交表单？但它被重定向到demo()函数执行它但不是但不是render_template。或者它确实会以某种方式回到相同的功能？
编辑2：
添加此代码的更多信息是在后台使用以下JavaScript
// Constants
var MAX_UPLOAD_FILE_SIZE = 1024*1024; // 1 MB
var UPLOAD_URL = "/upload";
var NEXT_URL = "/demo";
// List of pending files to handle when the Upload button is finally clicked.
var PENDING_FILES = [];
$(document).ready(function() {
// Set up the drag/drop zone.
initDropbox();
// Set up the handler for the file input box.
$("#file-picker").on("change", function() {
handleFiles(this.files);
});
// Handle the submit button.
$("#upload-button").on("click", function(e) {
// If the user has JS disabled, none of this code is running but the
// file multi-upload input box should still work. In this case they'll
// just POST to the upload endpoint directly. However, with JS we'll do
// the POST using ajax and then redirect them ourself when done.
e.preventDefault();
doUpload();
})
});
function doUpload() {
$("#progress").show();
var $progressBar = $("#progress-bar");
// Gray out the form.
$("#upload-form :input").attr("disabled", "disabled");
// Initialize the progress bar.
$progressBar.css({"width": "0%"});
// Collect the form data.
fd = collectFormData();
// Attach the files.
for (var i = 0, ie = PENDING_FILES.length; i < ie; i++) {
// Collect the other form data.
fd.append("file", PENDING_FILES[i]);
}
// Inform the back-end that we're doing this over ajax.
fd.append("__ajax", "true");
var xhr = $.ajax({
xhr: function() {
var xhrobj = $.ajaxSettings.xhr();
if (xhrobj.upload) {
xhrobj.upload.addEventListener("progress", function(event) {
var percent = 0;
var position = event.loaded || event.position;
var total = event.total;
if (event.lengthComputable) {
percent = Math.ceil(position / total * 100);
}
// Set the progress bar.
$progressBar.css({"width": percent + "%"});
$progressBar.text(percent + "%");
}, false)
}
return xhrobj;
},
url: UPLOAD_URL,
method: "POST",
contentType: false,
processData: false,
cache: false,
data: fd,
success: function(data) {
$progressBar.css({"width": "100%"});
data = JSON.parse(data);
// How'd it go?
if (data.status === "error") {
// Uh-oh.
window.alert(data.msg);
$("#upload-form :input").removeAttr("disabled");
return;
}
else {
// Ok! Get the UUID.
var uuid = data.msg;
//window.location = NEXT_URL + uuid;
window.location = NEXT_URL;
}
},
});
}
function collectFormData() {
// Go through all the form fields and collect their names/values.
var fd = new FormData();
$("#upload-form :input").each(function() {
var $this = $(this);
var name = $this.attr("name");
var type = $this.attr("type") || "";
var value = $this.val();
// No name = no care.
if (name === undefined) {
return;
}
// Skip the file upload box for now.
if (type === "file") {
return;
}
// Checkboxes? Only add their value if they're checked.
if (type === "checkbox" || type === "radio") {
if (!$this.is(":checked")) {
return;
}
}
fd.append(name, value);
});
return fd;
}
function handleFiles(files) {
// Add them to the pending files list.
for (var i = 0, ie = files.length; i < ie; i++) {
PENDING_FILES.push(files[i]);
}
}
function initDropbox() {
var $dropbox = $("#dropbox");
// On drag enter...
$dropbox.on("dragenter", function(e) {
e.stopPropagation();
e.preventDefault();
$(this).addClass("active");
});
// On drag over...
$dropbox.on("dragover", function(e) {
e.stopPropagation();
e.preventDefault();
});
// On drop...
$dropbox.on("drop", function(e) {
e.preventDefault();
$(this).removeClass("active");
// Get the files.
var files = e.originalEvent.dataTransfer.files;
handleFiles(files);
// Update the display to acknowledge the number of pending files.
$dropbox.text(PENDING_FILES.length + " files ready for upload!");
});
// If the files are dropped outside of the drop zone, the browser will
// redirect to show the files in the window. To avoid that we can prevent
// the 'drop' event on the document.
function stopDefault(e) {
e.stopPropagation();
e.preventDefault();
}
$(document).on("dragenter", stopDefault);
$(document).on("dragover", stopDefault);
$(document).on("drop", stopDefault);
}
我尝试集成以下链接中的功能：Flask Multiple Upload
无法理解为什么即使在点击/upload
/demo
有人可以帮我解决背景中发生的事情吗？
答案 0 :(得分：2)
简而言之，我的猜测是您错误地期望对XHR请求做出更改，以更改浏览器的地址。
以下是我认为正在发生的更详细的解释：
doUpload()调用Javascript函数doUpload()向UPLOAD_URL（POST /upload）发出XHR（ajax）请求upload()调用Python函数，成功上传后会生成“302 Found”重定向响应 / demo demo() Python函数呈现一些HTML，它作为“200 OK”响应返回success函数被触发并尝试将HTML解析为JSON JSON.parse(data)，这将失败我对您的浏览器，Javascript库，HTML模板和用户交互做了一些假设，但我认为这是您提供的代码中最可能的解释。
我的建议是首先尝试用以下内容替换return redirect(url_for("main.demo"))：
if is_ajax:
return ajax_response(True, upload_key)
else:
return redirect(url_for("main.demo"))
在这种情况下，成功上传后window.location = NEXT_URL将在doUpload()内执行，这将更改浏览器中的地址。