Flask receiving empty forms

Question

I'm trying to get a simple form set up in Flask for my own education. I've got a login.html page with this form code:

<form action="{{ url_for('login') }}" method="post">
    <div>
        <label for="username">Username</label>
        <div>
            <input type="text" id="username" name="username" placeholder="Username">
        </div>
    </div>
    <div>
        <label for="password">Password</label>
        <div>
            <input type="password" id="password" name="password" placeholder="Password">
        </div>
    </div>
    <div >
        <input class="btn" type="submit">
    </div>
</form>

I'm using code like the following to receive it, but Flask returns an empty request.form so I can't process it.

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        request.form['username']
        ...

I really don't want to learn another library (WTForms) right now, and I'm using bootstrap so that will add to the headache. What am I not seeing here with Flask/HTML?

Solution 1

I had this problem, but it was because I forgot to assign a name attribute to my input elements and I was trying to refer access the form data by the id attribute instead

i.e.

My HTML and Python was as shown below

HTML

<input type="text" id="usernameTxtBx">

Python

request.form['usernameTxtBx']

What I have done now:

HTML

<input type="text" name="username" id="usernameTxtBx">

Python

request.form['username']

I also needed to ensure that I was using a POST request. A GET request gave me an empty dictionary in my python code.

The OP made neither of these mistakes. But this may help someone that stumbles on this thread.

Solution 2

I had that problem. Some tools like postman or some libraries or web browser sends the data in a way that flask does not identify as posted values. From my point of view this is a flask issue.

This is the workaround I followed to solve it: 1 - I sent the information using json. Have a look to this:

How to send a JSON object using html form data

2 - I instead of getting the parameters using: value = request.form["myparamname"] I used this:

json_data = request.get_json(force=True) 

value = json_data["myparamname"]

Comments

[Ignas Butėnas]

does the request reaches your view function? Maybe form has different URL in action not "/login"? Try to put just "." in action. Just interested if it really lands in the view as you expect.

[avloss]

id="usernameTxtBx" is unnecessary, as it's not reflected in the request. You can access GET and POST variables together though request.args instead of request.form which only accesses POST

[Dave C]

Thank you! WTForms seems great, but is simply overkill for my needs.