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Flash

Overview

Flask natively provides flash and get_flashed_messages to set and get respectively feedback messages between requests to the user.

In the same context, it can be necessary to pass some data between request. Usually, to retain some data from one place to another, example from a form submission to a response page, flash_data and get_flashed_data will allow you to set data between request.

---

Usage

flash_data

version: 1.3.0

Similar to flask.flash, flash_data allows to hold data between request. Only one flash_data can be set at a time.

from assembly import Assembly, flash_data, get_flashed_data

class Index(Assembly):

  def post(self):
    """
    This will set the data to be retrieved back
    """
    data = {}
    flash_data(data)
    return redirect(self.index)

  def index(self):
    flashed_data = get_flashed_data()
    if flashed_data:
      ...

get_flashed_data

version: 1.3.0

Retrieve the data that was saved via flash_data. It will also remove

from assembly import Assembly, flash_data, get_flashed_data

class Index(Assembly):

  def index(self):
    """
    Retrieve data from flashed
    It will 
    """
    flashed_data = get_flashed_data()
    if flashed_data:
      ...

  def post(self):
    data = {}
    flash_data(data)
    return redirect(self.index)

flash

Flask native

flash to set a message

from assembly import Assembly
from flask import flash

class Index(Assembly):
  def index(self):
    flash("Welcome!")

  def with_category(self):
    flash("Hello", "info")
    flash("Something wrong!", "error")
    flash("You are about to do something bad", "warning")
    flash("Congratulations", "success")

get_flashed_messages

Flask native

get_flashed_messages to retrieved the messages. Usually in the template

{% with messages = get_flashed_messages(with_categories=true) %}
  {% if messages %}
    <ul class=flashes>
    {% for category, message in messages %}
      <li class="{{ category }}">{{ message }}</li>
    {% endfor %}
    </ul>
  {% endif %}
{% endwith %}

Filter Messages

{% with errors = get_flashed_messages(category_filter=["error"]) %}
{% if errors %}
<div class="alert-message block-message error">
  <a class="close" href="#">×</a>
  <ul>
    {%- for msg in errors %}
    <li>{{ msg }}</li>
    {% endfor -%}
  </ul>
</div>
{% endif %}
{% endwith %}