CODEWITHSUNDEEP
pythonhttp-redirectflask
F.N.B
F.N.B

Reputation: 1619

Flask: pass argument to another route

I'm making a app in what I need upload a file and work with it. I can upload successfully, but when I redirect, I can't pass the file (like a argument). The file is global objects.

@app.route('/analysis', methods = ['GET', 'POST'])
def analysis():
    if request.method == 'POST':
        file = getattr(g, 'file', None)
        file = g.file = request.files['file']
        return redirect(url_for('experiment'))
    else:
        return render_template('upload.html')

@app.route('/experiment', methods = ['GET', 'POST'])
def experiment():
    file = g.get('file', None)
    filename = secure_filename(file.filename)
    if request.method == 'POST':
        #do something with the file
        return render_template('experiment.html', data = data)
    else:
        return render_template('experiment.html')

This give this error:

AttributeError: '_RequestGlobals' object has no attribute 'get'

I'm doing wrong? Thanks!

Upvotes: 1

Views: 4297

Answers (1)

Sean Vieira
Sean Vieira

Reputation: 160063

First, g does not have a method called get, so that won't work. You are looking for getattr:

file = getattr(g, 'file', None)

Second, g is created at the beginning of each request and torn down at the end of each request. Setting g.file at the end of one request (right before it is torn down) will not make g.file available at the beginning of another.

The right way to do this is either to:

  • Store the file on the file-system (using a uuid for a name, for example) and pass the file's uuid to the other endpoint:

    @app.route("/analyze", methods=["GET", "POST"])
def analyze():
    if request.method == "POST":
        f = request.files['file']
        uuid = generate_unique_id()
        f.save("some/file/path/{}".format(uuid))
        return redirect(url_for("experiment", uuid=uuid))

@app.route("/experiment/<uuid>")
def experiment(uuid):
    with open("some/file/path/{}".format(uuid), "r") as f:
        # Do something with file here

  • Move the code from experiment into analyze

Upvotes: 8

Related Questions