django-devrecargar: A Python repository from scottwoodall

django-devrecargar

During the development of a Django application, do you get tired of:

Making a change to source code
Alt-tab to your browser
Refresh
Rinse and repeat

This project aims to make you more productive by keeping you in the text editor by automatically refreshing the browser after any file modification within your Django project (even CSS, JS or HTML).

Why devrecargar over other solutions?

Python only
No browser plugins
Easier for remote workflows where you are SSH'ed into a development server making changes but viewing the site with a browser on your local PC.

Installation

pip install devrecargar

Usage

Add devrecargar to INSTALLED_APPS in settings.py

Add an entry to urls.py:

 url(r'^devrecargar/', include('devrecargar.urls', namespace='devrecargar'))

Add a javascript snippet to a base template:

  <script>{% include "devrecargar/devrecargar.js" %}</script>

Configuration

devrecargar looks for BASE_DIR within settings.py as the default directory to recursively watch for file changes. If BASE_DIR doesn't exist then you need to set DEVRECARGAR_PATHS_TO_WATCH within settings.py. This should be a list of dictionaries like so:

   DEVRECARGAR_PATHS_TO_WATCH = [{
        'path': <an absolute path you want to watch>,  # required
        'recursive': True,  # not required, default is shown here
        'patterns': ['*.html', '*.js', '*.css']  # not required, default is shown here
        'ignore_directories': True,  # not required, default is shown here
   }]

If devrecargar doesn't find either of these variables then django.core.exceptions.ImproperlyConfigured will be raised.

FAQ

How It Works

The javascript snippet makes a Server-Sent Event (SSE) request to the Django devserver. Anytime the devserver process restarts the SSE request is disconnected within the browser and it will try to automatically reconnect. SSE will send an open event after the browser re-establishes the connection to the devserver after it's been restarted. The javascript snippet listens for the open event and issues a location.reload() that refreshes the browser.

After modifying a python file the devserver restarts automatically. To get CSS, JS, HTML support we use the watchdog module to listen for any file modifications. When a watchdog modification event happens an __init__.py file within the devrecargar project is "touched" which the devserver process notices because it's a python file and restarts itself, which triggers the SSE open event to fire.

How can I keep this out of my production environment?

In the HTML template wrap the javascript snippet in a debug conditional.

  {% if debug %}<script>{% include "devrecargar/devrecargar.js" %}</script>{% endif %}

You need django.template.context_processors.debug added to TEMPLATE_CONTEXT_PROCESSORS in settings.py. If you don't have TEMPLATE_CONTEXT_PROCESSORS defined then by default Django includes it.
Be sure your IP address is listed in INTERNAL_IPS within settings.py

In urls.py only add the route if DEBUG=True

  from django.conf import settings
  from django.conf.urls import include, patterns, url
  urlpatterns = patterns()  # all your other routes
  if settings.DEBUG:
      urlpatterns += (
          url(r'^devrecargar/', include('devrecargar.urls', namespace='devrecargar')
      )

Where does the name devrecargar come from?

Recargar is Spanish for "reload".

scottwoodall/django-devrecargar