javascript in flask code example

Example 1: how to add js in flask

<script src="{{url_for('static', filename='js/modernizr-2.6.2.min.js')}}"></script>

Example 2: call javascript function flask

from flask import Flask, render_template

app = Flask(__name__)


@app.route('/', methods=['GET', 'POST'])
def upload_file():
    if request.method == 'POST':
        #verify if the file is valid
        #here invoke js to do something (for example flash("test"))
        return render_template('upload.html', flash_message="True")

    return render_template('upload.html', flash_message="False")