Error Views

When an exception is raised in view, an 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 build 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'