[Django middleware for AJAX messages] Middleware for JSON responses. It adds to each JSON response array with messages from django.contrib.messages framework. It allows handle messages on a page with javascript. Django 1.10. #tags: django, python, ajax

messages.html

<div id="messages">
    {% for message in messages %}
        <div {% if message.tags %}class="alert alert-dismissable alert-{{ message.tags }}"{% endif %}>
            <a class="close" data-dismiss="alert" href="#">&times;</a>
            {{ message }}
        </div>
    {% endfor %}
</div>

middleware.py

from django.contrib import messages
import simplejson
from .utils import get_message_dict


class AjaxMessaging(object):
    """
    Middlware for JSON responses. It adds to each JSON response array with
    messages from django.contrib.messages framework.
    It allows handle messages on a page with javascript
    """

    def __init__(self, get_response):
        self.get_response = get_response
        # One-time configuration and initialization.

    def __call__(self, request):
        response = self.get_response(request)

        if request.is_ajax():
            if response['Content-Type'] in ["application/javascript",
                                            "application/json"]:
                try:
                    content = simplejson.loads(response.content)
                    assert isinstance(content, dict)
                except (ValueError, AssertionError):
                    return response

                content['django_messages'] = [get_message_dict(message) for
                                              message in
                                              messages.get_messages(request)]

                response.content = simplejson.dumps(content)
        return response

script.js

$(document).ready(function() {
    function addMessage(text, extra_tags) {
        var message = $(`
            <div class="alert alert-dismissable alert-${extra_tags}">\n
                <a class="close" data-dismiss="alert" href="#">&times;</a>\n
                    ${text}\n
            </div>`).hide();
        $("#messages").append(message);
        message.fadeIn(500);

        setTimeout(function() {
            message.fadeOut(500, function() {
                message.remove();
            });
        }, 3000);
    }

    $(document).ajaxComplete(function (e, xhr, settings) {
        var contentType = xhr.getResponseHeader("Content-Type");
        if (contentType == "application/javascript" || contentType == "application/json") {
            var json = $.evalJSON(xhr.responseText);
            $.each(json.django_messages, function (i, item) {
                addMessage(item.text, item.tags);
            });

        }
    }).ajaxError(function (e, xhr, settings, exception) {
        addMessage("There was an error processing your request, please try again.", "error");
    })

});