dcg-service

The module contains several features that provide functionality for various aspects of your application. Here is a breakdown of each feature:

1. Activity Events:

   • SqlAlchemy events are used to log user activity logs to Elasticsearch.
   • The dcg_service.core.events.py file contains more details about these events.
   • It includes SqlAlchemy model events such as before_create, after_create, before_update, and after_update.
   • The module includes an ActivityEvent class and registers the event class in the __init__.py file.
   • You can exclude specific model names from activity events by adding them to the EXCLUDE_MODEL_EVENTS list in the settings.py file.
   • You can add events to log activity by specifying them in the EVENTS list in the settings.py file.
   • The model file path can be specified using the APP_MODELS variable in the settings.py file.

2. Authentication/Permission:

   • User authentication is handled using JWT tokens.
   • You need to set the signing key and JWT algorithms in your settings file.
   • The is_authenticated function from dcg_service.core.permissions can be used as a decorator to enforce authentication on API views.

3. Service Cache:

   • The module includes a ServicePrice class that fetches service fee structure from an Elasticsearch index.
   • To retrieve service fee details, you can call ServicePrice(service_id, units).get_fee_details().
   • The get_fee_details function has an optional include_tax parameter to include/exclude tax details.
   • Additionally, you can use get_coupon_details to retrieve the total discount and coupon code.

4. Filters:

   • The module provides a Flask filter class that can be inherited to apply filters on querysets.
   • You can create a custom filter class by inheriting from Filter and implementing the add_filter method.
   • In your API views or functions, you can use the filter class by setting the filter_class attribute and calling apply() on an instance of the filter class.

5. Custom Response Handler:

   • You can change the default API response format by overriding the CustomResponse class from dcg_service.core.response.
   • The overridden class should provide a response JSON with the following structure: {"data": data, "message": message, "title": self.response.status, "code": self.response.status_code}.

6. Logger:

   • The module provides an overridden logger for better app debugging.

7. Encryption:

   • The module includes functions for encrypting and decrypting data.
   • You need to set the CIPHER_PRIVATE_KEY environment variable with a 16-character key for AES128 encryption.

8. Elastic-search DSL:

   • The module utilizes Elastic-search DSL for connecting and querying Elastic search indexes.
   • You need to set the ELASTICSEARCH_URL environment variable in your settings file.
   • The ACTIVITY_INDEX and SERVICE_CACHE_INDEX variables can be set to specify the indexes to be used for activity logs and service caching, respectively.

Elastic-search DSL

Elastic-search DSL is used to connect/query on elastic search indexes.

Must add following in your settings.py file:

ELASTICSEARCH_URL = os.environ.get('ELASTICSEARCH_URL')
ACTIVITY_INDEX = os.environ.get('ACTIVITY_INDEX', '').lower() # must be lower
SERVICE_CACHE_INDEX = os.environ.get('SERVICE_CACHE_INDEX')

Activity Events

SqlAlchemy events are used to log user activity logs to 'Elasticsearch'.

You can check dcg_service.core.events.py file for details.

Contains: SqlAlchemy model events before_create, after_create, before_update, after_update.

Activity event class,
registerd event class in __init__.py file

e.g.
def register_events():
    from . import events
    activity_events = events.ActivityEvent()
    activity_events.initialise_events()

register_events()

Add models names of your apps in settings.py to exclude from activity events.

e.g.  EXCLUDE_MODEL_EVENTS = ['Cart']

Add events to log activity.

e.g.  EVENTS = ['after_insert', 'before_update']

Add model file path.

e.g APP_MODELS = 'order_app.models'

Authentication/Permission

User authentication JWT token, set following details in your settings file.

    SIGNING_KEY = os.environ.get('SIGNING_KEY')
    JWT_ALGORITHMS = ['HS256']

Start using:

from dcg_service.core.permissions import is_authenticated

class ExampleView(views.MethodView):
"""
APIs Methods
-----------
GET: Get list.
"""
decorators = [is_authenticated]

def get(self):

Service cache

    Service price class to fetch service fee structure from `Elasticsearch` index.
    service_id: Respective service id,
    units: Units/quantity of service
    -----------------------------------------------------------------------------
    Call `ServicePrice(service_id, units).get_fee_details()` to get service fee details.
    
    For more information check file function docs.

Start using:

from dcg_service.core.services import ServicePrice
service = ServicePrice(service_id, units)
price_details = service.get_fee_details(include_tax=False)
total_discount, coupon_code = service.get_coupon_details()

Filters

Flask filter class, Inherit this class to apply filters on queryset.

e.g.

class ModelFilter(Filter):
    model = model_name
    def add_filter(self, *args, **kwargs):
        queryset = self.get_queryset()
        queryset = queryset.filter_by(**self.request_params)
        return queryset

use this filter class in your API view or function.

class APIView():
    filter_class = ModelFilter
    def get():
        queryset = self.filter_class(queryset).apply()

Custom Response handler

Change default API response, override dcg_service.core.response.CustomResponse class according to your need.

returns:

response_json = {
            "data": data,
            "message": message,
            "title": self.response.status,
            "code": self.response.status_code
        }

Logger

Logger override for maintain app debugging.

Encryption

Contain encrypt, decrypt functions for encryption.

Must add "CIPHER_PRIVATE_KEY" in your env:

key = os.environ['CIPHER_PRIVATE_KEY']  # Must Be 16 char for AES128