REST services¶

Pokie provides several mixins to help with the implementation of REST services; These mixins rely on DTO Objects and Repositories to provide the common CRUD and listing functions.

pokie.rest.RestServiceMixin¶

This mixin provides minimal CRUD functionality on top of a implementation-defined Repository; it can be used as a base implementation when prototyping services, as it enables gradual replacement of existing base behaviours with more complex implementations at a later stage in the development cycle.

The mixin provides the following methods:

Method	Result	Description
get(id_record)	DTO Record if exists, None if not	Fetch a record by primary key
delete(id_record)	None	Remove a record by primary key
insert(self, record)	primary key value	Insert a new record
update(id_record, record)	None	Update a record by primary key
exists(id_record)	True or False	Check if a record with the specified primary key exists
list(...)*	tuple(total_count, rows)	Perform a listing operation based on the specified criteria

list() uses DbGrid internally; check REST Views for more details.

To make use of this mixin, just make sure your service inherits pokie.rest.RestServiceMixin and provides a a repository property returnung a valid Repository object:

from pokie.constants import DI_DB
from rick.mixin import Injectable
from rick_db import Repository
from pokie.rest import RestServiceMixin
from my_fancy_app.dto import MyFancyRecord


class MyFancyService(Injectable, RestServiceMixin):

    @property
    def repository(self) -> Repository:
        return Repository(self.get_di().get(DI_DB), MyFancyRecord)

pokie.rest.RestService¶

RestService is the service implementation used on REST Views. It can also be used independently to build custom services - just fill record_class with your desired DTO Record class (and optionally repository_class with your custom Repository class); If no repository is specified, RestService will automatically build a generic Repository object based on record_class:

from pokie.rest import RestService
from my_fancy_app.dto import MyFancyRecord
from my_fancy_app.repository import MyFancyRepository

class MyFancyService(RestService):
    # specify DTO Record class to use
    record_class = MyFancyRecord
    # specify a custom Repository class to use
    #repository_class = MyFancyRepository

RestService can also be used to build custom services in runtime - in fact, it is what RestView does internally - it builds a generic RestService and adds it to the Service Locator:

from pokie.constants import DI_SERVICES
from pokie.rest import RestService
from pokie.http import PokieView
from my_fancy_app.dto import MyFancyRecord

class MyView(PokieView):

    def svc_custom(self) -> RestService:
        service_name = "my_custom_service_name"
        service_manager = self.di.get(DI_SERVICES)

        if not service_manager.contains(service_name):        
            # create new service object
            svc = RestService(self.di) 
            # set the DTO Record class
            svc.set_record_class(MyFancyRecord)
            # register the new service in the service manager    
            service_manager.register(service_name, svc)

            return svc

        return service_manager.get(service_name)