how to show bootstrap modal on rendering the same

Question

I have created a web application using flask and bootstrap. In this application, after putting the inputs and clicking the submit button I want to show the output or result in the same page in a bootstrap modal. But I could not redirect it properly. If there is any solution to it tell me. It will be very helpful. Thanks in advance. The codes are given below.

home.html

 <div class="container" align="left">
  <div class="panel panel-default" style="border:none;border-radius: 10px;">
    <div class="panel-body panel1">
        <form method="POST" action="/predict">
            <div class="row">
                <div class="col-sm-6"> 
                    <div class="form-group d2">
                        <label for="NewYork"><p class="p2">New York</p></label>
                        <input type="text" class="i1" name="NewYork"><br><br>
                        <small id="NYHelp" class="form-text text-muted s1">Enter 1 if the state selected is New York else enter 0</small>
                    </div>
                    <div class="form-group d2">
                        <label for="california"><p class="p2">California</p></label>
                        <input type="text" class="i1" name="California"><br><br>
                        <small id="CaliforniaHelp" class="form-text text-muted s1">Enter 1 if the state selected is New York else enter 0</small>
                    </div>
                    <div class="form-group d2">
                        <label for="Florida"><p class="p2">Florida</p></label>
                        <input type="text" class="i1" name="Florida"><br><br>
                        <small id="FloridaHelp" class="form-text text-muted s1">Enter 1 if the state selected is New York else enter 0</small>
                    </div>
                </div>
                <div class="col-sm-6">
                    <div class="form-group d2">
                        <label for="RnD_Spend"><p class="p2">RnD_Spend</p></label>
                        <input type="text" class="i1" name="RnD_Spend"><br><br>
                        <small id="RndSpendHelp" class="form-text text-muted s1">Enter RnD Spendings in US Dollar</small>
                    </div>
                    <div class="form-group d2">
                        <label for="Admin_Spend"><p class="p2">Admin_Spend</p></label>
                        <input type="text" class="i1" name="Admin_Spend"><br><br>
                        <small id="AdminSpendHelp" class="form-text text-muted s1">Enter Adminstration Spendings in US Dollar</small>
                    </div>
                    <div class="form-group d2">
                        <label for="Market_Spend"><p class="p2">Market_Spend</p></label>
                        <input type="text" class="i1" name="Market_Spend"><br><br>
                        <small id="MarketSpendHelp" class="form-text text-muted s1">Enter Market Spendings in US Dollar</small>
                    </div>
                </div>
            </div>
            <div class="row" align="right"><input class="btn btn1" type= "submit" value="Submit" data-toggle="modal" data-target="#myModal"></div>
        </form>
    </div>
 </div>
</div>

<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true">
 <div class="modal-dialog modal-dialog-centered" role="document">
  <div class="modal-content">
   <div class="modal-header">
    <h5 class="modal-title" id="exampleModalLongTitle">Modal title</h5>
    <button type="button" class="close" data-dismiss="modal" aria-label="Close">
      <span aria-hidden="true">&times;</span>
    </button>
   </div>
   <div class="modal-body">
    ...
   </div>
   <div class="modal-footer">
    <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
   </div>
  </div>
 </div>
</div>

app.py

 @app.route("/predict",methods=['GET', 'POST'])
 def predict():
   NewYork = float(request.form['NewYork'])
   California = float(request.form['California'])
   Florida = float(request.form['Florida'])
   RnD_Spend= float(request.form['RnD_Spend'])
   Admin_Spend= float(request.form['Admin_Spend'])
   Market_Spend = float(request.form['Market_Spend'])
   pred_args =[NewYork, California, Florida, RnD_Spend, Admin_Spend, Market_Spend]
   pred_args_arr = np.array(pred_args)
   pred_args_arr = pred_args_arr.reshape(1, -1)
   mul_reg = open("multiple_linear_model.pkl", "rb")
   ml_model = joblib.load(mul_reg)
   model_prediction = ml_model.predict(pred_args_arr)
   model_prediction = round(float(model_prediction), 2)
   return render_template('home.html', prediction = model_prediction)

Answer 1

I would say that it is usually not a good practice to redirect a user after form submission to the same page but with a modal shown (it is just not a good user experience), and I would recommend doing this through the use of AJAX.

Anyway, you can pass a flag that tells the HTML template renderer if it needs to show the modal. Something like this:

return render_template(
  'home.html',
  prediction=model_prediction,
  show_predictions_modal=True  // This is our flag
)

Then conditionally render your modal in the template:

{% if show_predictions_modal %}
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true">
 <div class="modal-dialog modal-dialog-centered" role="document">
  <div class="modal-content">
   <div class="modal-header">
    <h5 class="modal-title" id="exampleModalLongTitle">Modal title</h5>
    <button type="button" class="close" data-dismiss="modal" aria-label="Close">
      <span aria-hidden="true">&times;</span>
    </button>
   </div>
   <div class="modal-body">
    ...
   </div>
   <div class="modal-footer">
    <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
   </div>
  </div>
 </div>
</div>
{% endif %}