Flask:处理输入时，服务器发送事件(SSE)流功能停止 [英] Flask: Server-sent event (SSE) stream function is halted when processing input
问题描述
I'm working on a problem very similar to this one (lots of code copied from there): Displaying a progress bar for processing an input uploaded via a html form.
HTML:
<script>
function getProgress() {
var source = new EventSource("/progress");
source.onmessage = function(event) {
$('.progress-bar').css('width', event.data+'%').attr('aria-valuenow', event.data);
$('.progress-bar-label').text(event.data+'%');
// Event source closed after hitting 100%
if(event.data == 100){
source.close()
}
}
}
</script>
<body>
<div class="container">
...
<form method="POST" action="/process" enctype="multipart/form-data">
<div class="form-group">
...
<input type="file" name="file">
<input type="submit" name="upload" onclick="getProgress()" />
</div>
</form>
<div class="progress" style="width: 80%; margin: 50px;">
<div class="progress-bar progress-bar-striped active"
role="progressbar" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100" style="width: 0%">
<span class="progress-bar-label">0%</span>
</div>
</div>
</div>
</body>
app.py:
@app.route('process')
def process_inputs():
...
r.set("progress", progress)
...
@app.route('/progress')
def progress():
def progress_stream():
progress = r.get("progress")
while progress < 100:
yield "data:" + str(progress) + "\n\n"
time.sleep(1)
return Response(progress_stream(), mimetype='text/event-stream')
据我了解，progress和process_input函数应同时运行，因此progress可以在处理进行时更新进度条.但是，由于progress被暂停直到``process_input`完成为止，这是行不通的.
From my understanding, the progress and process_input functions should run simultaneously, so progress can get update the progress bar while the processing takes place. However, this doesn't work since progress is halted until ``process_input` is finished.
如何使这两个功能同时运行?我认为这将由Flask的threaded功能自动处理.
How can I get these two function to run simultaneously? I thought this would automatically be handled by Flask's threaded functionality.
推荐答案
显然是浏览器问题:使用Chrome可以按预期运行，但不能使用Firefox.看起来Firefox在等待POST请求(?)时不处理传入的SSE
Apparently it's a browser issue: with Chrome it works as intended, but not with Firefox. Looks like Firefox doesn't process incoming SSEs while waiting on the POST-request (?)
这篇关于Flask:处理输入时，服务器发送事件(SSE)流功能停止的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
