Allow only one flask request for a particular route

I have a flask app which uses angularjs front end. I make the http request through $http service. As shown in the code below.

$http.post('/updateGraph', $scope.graphingParameters).success(function(response) {
        $scope.graphingParameters.graph = response.graph;
        $scope.listUnits = JSON.parse(response.listUnits);
        $scope.myHTML = $sce.trustAsHtml($scope.graphingParameters.graph);
        $scope.showME = true;
    })

and the updateGraph function in flask is as follows.

@app.route('/updateGraph', methods = ['POST'])
     def updateGraph():
           selectValues = request.json['selectValues']
           selectSelected = np.array(request.json['selectSelected']).tolist()
           if len(selectSelected) == 0:
                selectSelected = np.array([selectValues[1:3]]).tolist()
           fig, listUnits = plot_Stock_vs_Sales(selectSelected)
           graph = py_offline.plot(fig, include_plotlyjs=False, output_type='div', show_link=False)
           return json.dumps({ 'graph': graph, 'listUnits':listUnits.reset_index().to_json(orient='records')})

The problem is that suppose make the $http post from angular twice, The flask route is running twice. this is the code from the server.

Seconds:92 127.0.0.1 - - [12/Sep/2016 09:46:35] "POST /updateGraph HTTP/1.1" 200 - Seconds:110 127.0.0.1 - - [12/Sep/2016 09:47:02] "POST /updateGraph HTTP/1.1" 200 -

I want to either make the $http post request to only allow one request or make flask run only one route per user. Is this possible through flask? if not what would be the best approach through angular?

---

From your description of the situation, this is something that would be better solved on the client side.

I would just set a flag (define it on a global or class level) if there's a request already ongoing for that task. For example:

if (processing) {
    return;
}
processing = true;
$http.post('/updateGraph', $scope.graphingParameters).success(function(response) {
        $scope.graphingParameters.graph = response.graph;
        $scope.listUnits = JSON.parse(response.listUnits);
        $scope.myHTML = $sce.trustAsHtml($scope.graphingParameters.graph);
        $scope.showME = true;
        processing = false;
    })

This implementation can also be used to hide/disable the button or whatever triggers the request from the user so that they cannot trigger it while there's an ongoing request.

Note that I'm not very familiar with angular 1, so you might want to trigger that processing = false after the request and not only on success .

---

You could look at implementing a task or work queue using something like Redis and python-rq .

Essentially, when the route is run, rather than perform your work immediately, you queue a task (in this case, to update your graph) to run asynchronously. This way you can ensure that the graph is updated atomically, or using some other criteria of your choosing (for example only once every ten minutes).

链接地址: http://www.djcxy.com/p/71898.html

上一篇: 将HTML页面替换为通过AJAX检索的内容

下一篇: 只允许一个烧瓶请求一个特定的路线