How can I pass arguments into redirect(url_for()) of Flask?

Question

I'm trying to understand how best to redirect and pass arguments using Flask

Below is my code, I'm finding that x and y are not making it into the template.

Is my syntax correct? Am I missing something basic? I am able to render the template, but I want to redirect to the url /found, rather than just returning the template for find.html

@app.route('/found')
def found(email,listOfObjects):
  return render_template("found.html",
      keys=email,obj=listOfObjects)

@app.route('/find', methods=['GET','POST'])
def find():
    if request.method == 'POST':
        x = 3
        y = 4
        return redirect(url_for('found',keys=x,obj=y))

    return render_template("find.html")

score 111 · Accepted Answer · edited Dec 24 '22 at 21:49

111

The redirect is fine, the problem is with the found route. You have several ways to pass values to an endpoint: either as part of the path, in URL parameters (for GET requests), or request body (for POST requests).

In other words, your code should look as follows:

@app.route('/found/<email>/<listOfObjects>')
def found(email, listOfObjects):
  return render_template("found.html",
      keys=email, obj=listOfObjects)

Alternatively:

@app.route('/found')
def found():
  return render_template("found.html",
      keys=request.args.get('email'), obj=request.args.get('listOfObjects'))

Also, your redirection should provide request parameters, not template parameters:

return redirect(url_for('found', email=x, listOfObjects=y))

edited Dec 24 '22 at 21:49

starball

20,030
7
43
238

answered Nov 16 '14 at 13:27

Adam Byrtek

12,011
2
32
32

7

If this is what you were looking for then feel free to upvote and/or accept the answer. – Adam Byrtek Nov 16 '14 at 19:58
3

Using redirect(url_for()) can an object be passed as a parameter? – tw1742 May 07 '16 at 04:02
1

I can't see why it should be like this. We can already do `defaults={. . .}` why can't we just chuck in a few arguments? – Luke Apr 28 '17 at 10:33
1

I have the same question as @tw1742. I am attempting to do exactly this but with a pandas dataframe and it doesn't seem to work. anyone know how to pass complex objects like dataframes? – greenteam May 30 '19 at 19:40
i think you can only pass serializable objects, as JSON objects, and there is a size limit that if exceeded the request gets ignored by the browsers @greenteam – BHA Bilel Jul 03 '20 at 23:04

How can I pass arguments into redirect(url_for()) of Flask?

1 Answers1

Linked