Can't retrieve variable from url with Flask app after submitting search form

Question

I would like to present a new view after the user submits a search form. I made it as the same way as I do with my other views, but unfortunately this time doesn't happens anything, I can't retrieve the content from the app route. (So this question is not a duplicate of this question, the issue occurs only after submitting the form, it works perfectly in every other situation.) I write something into the form, submit it, then the url changes in the browser, but the view doesn't change anyway. I'm almost sure that it's because the ? and = in the search slug, but don't know how should I deal with them in the Python code.

Actually when I submit the form my browser redirects me to an url like this:

http://domain/.com/?search=content+from+textfield

And this is how I tried to catch the content from the search field and present a new view on the Flask's side:

@app.route('/?search=<url_content>', methods=['POST'])
def hello_url(url_content): 
return render_template("search-results.html", searchString = url_content])

I would really appreciate if somebody could show me the right way, basically I just wanna retrieve the value of <url_content> inside the hello_url function after the search button tapped.

Here's my html:

<form>
 <div class="form-group">
    <input type="search" class="form-control text-center input-lg" id="inputSearch" name="search" placeholder="search">
    </div>
     <br>
<div class="text-center"><button type="submit" class="btn btn-primary btn-lg">Search!</button></div>
</form>

Possible duplicate of [How to obtain values of parameters of get request in flask?](http://stackoverflow.com/questions/22383458/how-to-obtain-values-of-parameters-of-get-request-in-flask) — Robert Moskal, Dec 05 '15 at 15:27
@RobertMoskal That question is about the basic situation, when you present views, as I mentioned my problem occurs only after submitting the form. — sabiv, Dec 05 '15 at 15:32
I will also point out that your view function responds to `POST` yet since your form is missing an action, it is implicitly set to `GET`. Either way it is a bit odd that your looking for query string data in a `POST` method instead of form data. — Josh J, Dec 05 '15 at 16:17

davidism · Accepted Answer · 2015-12-05T16:12:17.200

You're confusing url parameters, which are captured with <variable>, with query parameters, which are accessed in request.args. Remove the query parameter from your route definition and access it in the view.

from flask import request

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/search')
def search():
    search = request.args.get('search')  # will be None if form wasn't submitted
    # do something with search
    return render_template('search.html', search=search)

index.html:

<form action="{{ url_for('search') }}">
    <input name="search"/>
    <input type="submit" value="Search"/>
</form>

score 1 · Answer 2 · edited Aug 31 '18 at 15:01

You have several mistakes. First you are incorrectly specifying the route on the server side. You can't capture or specify query parameters on the flask route. You can have something like

@app.route('/search')

Secondly you need to provide an action and method on your form. So

<form action="{{ url_for("search") }}" method="POST">

If you don't specify the method, it will be sent as a GET, and the fields will appear as query arguments. If you do a post then you can retrieve the fields like so on the server side:

request.form['inputSearch']

I introduced the /search route, but you could do the same from the root "/".

Can't retrieve variable from url with Flask app after submitting search form

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