meg-django-remote-forms 1.2.1

A platform independent form serializer for Django.

# django-remote-forms

A package that allows you to serialize django forms, including fields and widgets into Python
dictionary for easy conversion into JSON and expose over API

Please go through my [djangocon US 2012 talk](http://www.slideshare.net/tarequeh/django-forms-in-a-web-api-world)
to understand the problem sphere, motivations, challenges and implementation of Remote Forms

## Sample Implementation

If you don't mind digging around a little bit to learn about different the components that might be
necessary for an implementation of django-remote-forms, check out
django Remote Admin [django-remote-admin](https://github.com/tarequeh/django-remote-admin)

## Usage

### Minimal Example

```python
from django_remote_forms.forms import RemoteForm

form = LoginForm()
remote_form = RemoteForm(form)
remote_form_dict = remote_form.as_dict()
```

Upon converting the dictionary into JSON, it looks like this:

```json
{
"is_bound": false,
"non_field_errors": [],
"errors": {},
"title": "LoginForm",
"fields": {
"username": {
"title": "CharField",
"required": true,
"label": "Username",
"initial": null,
"help_text": "This is your django username",
"error_messages": {
"required": "This field is required.",
"invalid": "Enter a valid value."
},
"widget": {
"title": "TextInput",
"is_hidden": false,
"needs_multipart_form": false,
"is_localized": false,
"is_required": true,
"attrs": {
"maxlength": "30"
},
"input_type": "text"
},
"min_length": 6,
"max_length": 30
},
"password": {
"title": "CharField",
"required": true,
"label": "Password",
"initial": null,
"help_text": "",
"error_messages": {
"required": "This field is required.",
"invalid": "Enter a valid value."
},
"widget": {
"title": "PasswordInput",
"is_hidden": false,
"needs_multipart_form": false,
"is_localized": false,
"is_required": true,
"attrs": {
"maxlength": "128"
},
"input_type": "password"
},
"min_length": 6,
"max_length": 128
}
},
"label_suffix": ":",
"prefix": null,
"csrfmiddlewaretoken": "2M3MDgfzBmkmBrJ9U0MuYUdy8vgeCCgw",
"data": {
"username": null,
"password": null
}
}
```

### An API endpoint serving remote forms

```python
from django.core.serializers.json import simplejson as json, DjangoJSONEncoder
from django.http import HttpResponse
from django.middleware.csrf import CsrfViewMiddleware
from django.views.decorators.csrf import csrf_exempt

from django_remote_forms.forms import RemoteForm

from my_awesome_project.forms import MyAwesomeForm


@csrf_exempt
def my_ajax_view(request):
csrf_middleware = CsrfViewMiddleware()

response_data = {}
if request.method == 'GET':
# Get form definition
form = MyAwesomeForm()
elif request.raw_post_data:
request.POST = json.loads(request.raw_post_data)
# Process request for CSRF
csrf_middleware.process_view(request, None, None, None)
form_data = request.POST.get('data', {})
form = MyAwesomeForm(form_data)
if form.is_valid():
form.save()

remote_form = RemoteForm(form)
# Errors in response_data['non_field_errors'] and response_data['errors']
response_data.update(remote_form.as_dict())

response = HttpResponse(
json.dumps(response_data, cls=DjangoJSONEncoder),
mimetype="application/json"
)

# Process response for CSRF
csrf_middleware.process_response(request, response)
return response
```

## djangocon Proposal

This is a bit lengthy. But if you want to know more about my motivations behind developing django-remote-forms
then read on.


>In our quest to modularize the architecture of web applications, we create self-containing backend
>systems that provide web APIs for programmatic interactions. This gives us the flexibility to
>separate different system components. A system with multiple backend components e.g. user profile
>engine, content engine, community engine, analytics engine may have a single frontend application
>that fetches data from all of these components using respective web APIs.

>With the increased availability of powerful JavaScript frameworks, such frontend applications are
>often purely JS based to decrease application footprint, increase deployment flexibility and
>separate presentation from data. The separation is very rewarding from a software engineering
>standpoint but imposes several limitations on system design. Using django to construct the API for
>arbitrary consumers comes with the limitation of not being able to utilize the powerful django form
>subsystem to drive forms on these consumers. But is there a way to overcome this restriction?

>This is not a trivial problem to solve and there are only a few assumptions we can make about the
>web API consumer. It can be a native mobile or desktop - application or browser. We advocate that
>web APIs should provide sufficient information about 'forms' so that they can be faithfully
>reproduced at the consumer end.

>Even in a API backend built using django, forms are essential for accepting, filtering, processing
>and saving data. The django form subsystem provides many useful features to accomplish these tasks.
>At the same time it facilitates the process of rendering the form elements in a browser
>environment. The concepts of form fields combined with widgets can go a long way in streamlining
>the interface to interact with data.

>We propose an architecture to serialize information about django forms (to JSON) in a framework
>independent fashion so that it can be consumed by any frontend application that renders HTML. Such
>information includes but is not limited to basic form configurations, security tokens (if
>necessary), rendering metadata and error handling instructions. We lovingly name this architecture
>django-remote-forms.

>At WiserTogether, we are in the process of building a component based architecture that strictly
>provides data endpoints for frontend applications to consume. We are working towards developing
>our frontend application for web browsers using backbone.js as MVC and handlebars as the templating
>engine. django-remote-forms helps us streamline our data input interface with the django forms
>living at the API backend.