Mastering Flask Web Development - Second Edition

The get_flashed_messages() function

The get_flashed_messages() function returns a list of all the messages passed through the flash() function in Flask. The flash function is a simple function that queues messages—which consist of Python tuples of (category, message) phrases—for the get_flashed_messages function to consume, as shown in the following code:

{% with messages = get_flashed_messages(with_categories=true) %}    {% if messages %}        {% for category, message in messages %}        <div class="alert alert-{{ category }} alert-dismissible"                      role="alert">        <button type="button" class="close" data-dismiss="alert" aria-      label="Close"><span aria-hidden="true">&times;</span></button>            {{ message }}        </div>        {% endfor %}    {% endif %}{% endwith %}

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