如何在html模板中从jinja2循环中请求

Question

so i have a feed on my website listing all the new "proposals" made recently. These are listed in a jinja2 loop in my html template. The thing is, that i have rating buttons under each proposal, and i want to be able to get the rating the user clicked on in python and then send it to the database. But i don't really know how to do that as i'm still a beginner..

So here is what i have in my html template :

            {% for proposition in propositions %}
            <div class="feed_propBox"> <!--prop Box: Begin-->
                <form method="POST" action="rate">

                    <p  id="titre" name="titre" value="{{proposition.title}}">{{ proposition.title }}</p>
                    <p  id="perso" name="perso">{{ proposition.date }}</p>
                    <p  id="content" name="content">{{ proposition.content }}</p>

                    <div class="ratingBlock">
                        <button type="submit" class="mThree ratingButton" id="m3" name="rate" value="m3">-3</button>
                        <button type="submit" class="mTwo ratingButton" id="m2" name="rate" value="m2">-2</button>
                        <button type="submit" class="mOne ratingButton" id="m1" name="rate" value="m1">-1</button>
                        <button type="submit" class="zero ratingButton" id="z" name="rate" value="z">0</button>
                        <button type="submit" class="pOne ratingButton" id="p1" name="rate" value="p1">1</button>
                        <button type="submit" class="pTwo ratingButton" id="p2" name="rate" value="p2">2</button>
                        <button type="submit" class="pThree ratingButton" id="p3" name="rate" value="p3">3</button>
                    </div>
                </form>

            </div> <!--prop Box: End-->
            {% endfor %}

In my python views.py, i have this for my feed :

@bp.route('/rate', methods=['POST','GET'])
def rate():
    if request.method == 'POST':
        note_list = ["m3", "m2", "m1", "z", "p1", "p2", "p3"]
        for i in note_list:
            titre = request.form["titre"]
            note = request.form['rate']
            if note == i:
                note = note_list.index(i)
                client.POSTS.rating.insert_one({"title" : titre, "rate" : note})
    return redirect(url_for('.proposer'))

But well, i get this error when clicking on a rating button :

Traceback (most recent call last):
  File "/Library/Python/3.7/site-packages/flask/app.py", line 2309, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Library/Python/3.7/site-packages/flask/app.py", line 2295, in wsgi_app
    response = self.handle_exception(e)
  File "/Library/Python/3.7/site-packages/flask/app.py", line 1741, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/Library/Python/3.7/site-packages/flask/_compat.py", line 35, in reraise
    raise value
  File "/Library/Python/3.7/site-packages/flask/app.py", line 2292, in wsgi_app
    response = self.full_dispatch_request()
  File "/Library/Python/3.7/site-packages/flask/app.py", line 1815, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Library/Python/3.7/site-packages/flask/app.py", line 1718, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/Library/Python/3.7/site-packages/flask/_compat.py", line 35, in reraise
    raise value
  File "/Library/Python/3.7/site-packages/flask/app.py", line 1813, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Library/Python/3.7/site-packages/flask/app.py", line 1799, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/Users/gabriel/Dropbox/Evrisops/Evrisops_Server/views/routes.py", line 252, in rate
    titre = request.form["titre"]
  File "/Library/Python/3.7/site-packages/werkzeug/datastructures.py", line 431, in __getitem__
    raise exceptions.BadRequestKeyError(key)
werkzeug.exceptions.HTTPException.wrap.<locals>.newcls: 400 Bad Request: KeyError: 'titre'

Anyways, i think the problem may only come from "title" but i have no idea how to fix that either...

BTW, do you guys know how to append a value to an array in a json document ? Using python and mongodb operator :/

Thanks alot :)

Answer 1

I think the error comes from this line :

titre = request.form["titre"]

You probably don't have a titre key in the request.form object. To debug this, I suggest to add a print request.form in the loop so you can see the structure of the object.

Moreover, if request.form["titre"] is empty, it is probably because you are setting a value attribute on a <p> element which is not allowed in HTML.

According tho this page the value attribute can't be set on a <p> element. Try to switch to an <input> element.

Answer 2

Okay, found the way to do that some time ago If it can help anyone : just use request.form.get('') instead of request.form[''] Along with an input with hidden property to get the value of the proposition.title. :)