CODEWITHSUNDEEP
pythonhttpflaskhttpresponse
Deekshith Anand
Deekshith Anand

Reputation: 2662

Return custom http code after redirection in flask

there I am new to the flask. The scenario: I am trying to redirect to a certain route after submitting the form. So I am using flask redirect for this along with code parameter.

@topics_bp.route('/create_topic/',methods =['GET','POST'] )
def create_topic():
    if request.method == 'GET':
        #send the form for create topic!
        formData = TopicForm()
        return render_template('create-topic.html',form = formData)
    if request.method == 'POST':
        # check the post method and redirect
        
        return redirect(url_for('topic.topics'),code=201)

Basically , I want to return HTTP code 201 for a record created and then redirect to the intended route. But if I do like this, it simply returns a redirection page. Every time I need to click manually. Redirection page

Is there any workaround to return 201 code and redirect automatically? Thanks in advance!

Upvotes: 1

Views: 986

Answers (1)

Martijn Pieters
Martijn Pieters

Reputation: 1121176

I want to return HTTP code 201 for a record created and then redirect to the intended route.

That's not something you can do with HTTP. A redirect is itself a specific HTTP 30x status code:

In HTTP, redirection is triggered by a server sending a special redirect response to a request. Redirect responses have status codes that start with 3, and a Location header holding the URL to redirect to.

Either you return a 201 status code or you return one of the HTTP redirection status codes. You can't do both.

The flask.redirect() function generates a valid 30x response (with the required Location header), and the documentation for the function states what redirect status codes are supported:

Supported codes are 301, 302, 303, 305, 307, and 308. 300 is not supported because it’s not a real redirect and 304 because it’s the answer for a request with a request with defined If-Modified-Since headers.

The function doesn't enforce this, however; the status code is not validated.

You need to distinguish between a browser and other clients here. A 201 Created response is something you typically return from a REST API to a client that expects simple JSON or XML interactions at a programmable level. Redirects, on the other hand, are more typically used in a frontend, in the presentation layer.

If you are coding a HTML-based front-end, just return a redirect. Humans don't read response codes, they read rendered HTML pages. They don't care and don't need to know the exact HTTP codes used to make the browser do the right thing. Given that your route also includes a form, you are almost certainly building a site for humans and not for programmatic clients.

If you are building a REST API, then return a 201 response, and document that the API client will have to make a new request based on the Location header you included, or on something in the body of the response. A HTML browser will not follow the Location header on 201 responses however.

I then would not use the redirect() function for this, even if it does allow you to use 201 as the status code, because it always produces a (simple) HTML body containing the text you see in your browser about an automatic redirect.

Upvotes: 5

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