Using JQuery/AJAX to call a function and use it's value in a Flask template

Question

I have a flask app and want to update a value in a template periodically. This value will come from a Flask route. For example my views are defined like so:

from . import main
from flask import render_template


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


@main.route('/price')
def price():
    return 5

Now my index.html:

<html>
<body>

<p id="p1">Replace this text</p>

<script>
  setInterval(function(){
    document.getElementById("p1").innerHTML = "some value";
  }, 5000);
</script>

<p>The paragraph above was changed by a script.</p>

</body>
</html>

How can I call the /price route from within the js and then use the returned value in id=p1?

score 3 · Accepted Answer · answered Jul 23 '17 at 09:24

I think, it is better to return a structured response (json/xml) from views.

So, my first suggestion is about your 'price' view:

views

@app.route('/price')
def price():
    # obtain jsonify from Flask: from flask import jsonify
    # you may change the output/format as you need
    return jsonify({'value': 5})

Using jquery (which simplifies AJAX calls),

index.html

<html>
<body>

<p id="p1">Replace this text</p>

<script>
  setInterval(function(){
    $.get('/price',function(data) {
        // here, we have the data object returned by 'price' endpoint
        // you can access its attributes as a regular JSON object
        document.getElementById("p1").innerHTML = data.value;
    });
  }, 5000);
</script>

<p>The paragraph above was changed by a script.</p>

</body>
</html>

Using JQuery/AJAX to call a function and use it's value in a Flask template

1 Answers1