Introduction.

This code was originally created by Michael "Svedrin" Ziegler (https://bitbucket.org/Svedrin/djextdirect). I made some changes so it's now compatible with ExtJS 4.x (probably ExtJS 5 too) and Django 1.6.

I also implemented some extra features:

• Improved traceback formating when on debug mode to make it more easily readeable in Chrome or Firefox. The python traceback is now a list of strings and it's easy to read in the debug tools.

• Custom errors messages can be propagated to the client without the traceback when not on debug mode. You can create custom exceptions with a special flag. This flag tels the app that the error message shoud go to the client even in production mode and without the traceback.

Instalation.

Put the djextdirect folder in you PYTHONPATH or in your project tree.

Usage.

First instantiate the provider somewhere, it could be in your views.py

from djextdirect import provider

EXT = provider.Provider(name="Ext.app.REMOTING_API", autoadd=False)

Then add the line url(r'^direct/', include(EXT.urls)) to the tuple of URLs,

like that:

from myapp.views import EXT

urlpatterns = patterns('',
                       url(r'^direct/', include(EXT.urls)),
                       # ... other urls ....
                       )

In you views, decorate your functions to expose them to the client.

You can decorate functions:

@EXT.register_method("Namespace")
def a_function(request, data):
    result = data['property1'] * data['property2']
    # etc ... etc ...
    return result

In the client you would call Namespace.a_function({property1: 10, property2: 10});

You can also use classes and staticmethods to organize your code:

class ClassToOrganizeCode(object):
    @staticmethod
    @EXT.register_method("ClassToOrganizeCode")
    def a_staticmethod(request, data):
        result = data['property1'] * data['property2']
        if result > 100:
            raise MyCustomError(result)
        else:
            return result

In the client you would call ClassToOrganizeCode.a_staticmethod({property1: 10, property2: 10});

In order to propagate error messages:

It's possible to propagate error messages to the client even in production (DEBUG=False). For that you need to define exceptions with a special flag. To flag the exception add the property visible=True to the class.

class MyCustomError(Exception):
    # This flag tels the app that the error message shoud go to the client even in production moode.
    visible = True

    def __init__(self, value=None):
        self.message = "Value is over 100, it is {}.".format(value)

    def __str__(self):
        return self.message

In the client you can use the error message to display messages to the user, in the example I log to the console, but you can open a window, or pop up a toast with the error:

ClassToOrganizeCode.a_staticmethod({property1: 10, property2: 20},
    //callback
    function(result, response, ok){
        if (ok){
            console.log(result)
        }
        else{
            console.error(response.message)
        }
    }
);

If the exception does not have the flag, in the production mode (DEBUG=False), the provider passes the message "Internal Error". In the debug mode (DEBUG=True) the provider passes the error message and the traceback for all errors.