Flash Messages aren't appearing on page
Question
I'm creating a currency converter using python and flask, and trying to flash error messages for invalid inputs. The form automatically routes to the error checks upon submission. I have been manipulating the inputs to purposely raise errors and a KeyError is showing in my browser, but not flashing on my page.
These are the checks I'm trying to do:
def check_valid_code():
converting_from = (request.form['converting_from']).upper()
converting_to = (request.form['converting_to']).upper()
c= CurrencyCodes()
try:
c.get_symbol(converting_from)
except KeyError:
flash("{converting_from} is not a valid currency code!")
try:
c.get_symbol(converting_to)
except KeyError:
flash("{converting_to} is not a valid currency code!")
def check_valid_number():
amount = request.form['amount']
if amount.isnumeric() == True:
amount= float(amount)
return amount
else:
flash("Not a valid amount.")
My base.html (using Bootstrap) where the messages should appear:
<body>
<div class="container" style="min-height:100% width:80%">
<div class="col-sm-4">
{% with errors = get_flashed_messages(category_filter=["danger"]) %}
{% if errors %}
{%- for message in errors %}
<div class="alert alert-danger alert-dismissible fade show" role="alert">
<span>{{ message }}</span>
<button type="button" class="close" data-dismiss="alert" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
</div>
{% endfor -%}
{% endif %}
{% endwith %}
</div>
{% block content %}
{% endblock %}
</div>
</body>
1 answers
solution1
0 2020-11-24 21:26:17
You should use render_template library from Flask and your code looks like this:
from flask import Flask, render_template
def check_valid_code():
converting_from = (request.form['converting_from']).upper()
converting_to = (request.form['converting_to']).upper()
c= CurrencyCodes()
try:
c.get_symbol(converting_from)
except KeyError:
message = "{converting_from} is not a valid currency code!"
try:
c.get_symbol(converting_to)
except KeyError:
message = "{converting_to} is not a valid currency code!"
return render_template('base.html',message=message)
def check_valid_number():
amount = request.form['amount']
if amount.isnumeric() == True:
amount= float(amount)
return amount
else:
message = "Not a valid amount."
return render_template('base.html',message=message)
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