Error Views

When an exception is raised in view, a URL is not available or a view raised a Forbidden error, a Lona error view is called. Lona error views behave like normal Lona views and use the same API.

Lona has error views for 403, 404 and 500 errors built-in that use overrideable templates. To customize your Lona application you can override the templates or the entire views.

Custom Templates

Lona uses settings.ERROR_403_TEMPLATE which is set to lona/403.html by default. You can reset this value or provide a template under this path.

403 templates get the lona.errors.ForbiddenError passed in their template context.

403 Errors

<!--  templates/lona/403.html -->

<h1>403</h1>
<p>Forbidden</p>

404 Errors

Lona uses settings.ERROR_404_TEMPLATE which is set to lona/404.html by default. You can reset this value or provide a template under this path.

<!--  templates/lona/404.html -->

<h1>404</h1>
<p>Not Found</p>

500 Errors

Lona uses settings.ERROR_500_TEMPLATE which is set to lona/500.html by default. You can reset this value or provide a template under this path.

500 templates get the python exception passed in their template context.

<!--  templates/lona/500.html -->

<h1>500</h1>
<p>Internal Error</p>

Custom Views

403 Errors

# views/error_403.py

from lona import LonaView


class Error403View(LonaView):
    def handle_request(self, request, exception):
        return {
            'template': 'lona/403.html',
            'request': request,
        }

# settings.py

ERROR_403_VIEW = 'views/error_403.py::Error403View'

404 Errors

# views/error_403.py

from lona import LonaView


class Error404View(LonaView):
    def handle_request(self, request):
        return {
            'template': 'lona/404.html',
            'request': request,
        }

# settings.py

ERROR_404_VIEW = 'views/error_404.py::Error403View'

500 Errors

# views/error_500.py

from lona import LonaView


class Error500View(LonaView):
    def handle_request(self, request, exception):
        return {
            'template': 'lona/500.html',
            'request': request,
            'exception': exception,
        }

# settings.py

ERROR_404_VIEW = 'views/error_500.py::Error403View'