Checkout shopping list shows a list of product which can be added to the basket and making checkout with their discounts
This project uses Material design with Clean architecture by means of Model-View-Presenter (MVP) with Repository pattern
as well as Dagger 2 for Dependency Injection, trying to respect SOLID principles as much as possible.
At this open-source project, it is decoupled between android and domain modules or high level layers.
This means, android is strongly coupled with the Android framework and domain is decoupled from it, and can be re-used for other purposes when
required as is purely Java based, but not framework coupled.
Inside the those modules, there are some good practices being employed, for instance:
- There is an implementation of the repository pattern with a Network datasource (it could be extended to have others if required such as InternetDataSource and so on).
Retrofit 2 is the Network library which uses OkHttp as its client, this makes calls to the API, transforming the responses to models, for this purpose and properly handling the different requests on background threads with a pool of threads which passes their use cases result and avoids to lock the UI thread.
The exchange between the different layers is as follows:
- Repository layer:
- from the models coming from a concrete data source to the Repository (repository is the responsible of managing from 1 to n datasources, in this case only network datasource)
- from the Repository to their associated Interactor (or use case)
- this Repository contains cached information for the shopping list content in RAM memory, being part of its implementation
- Interactor layer: from the Interactor, which is responsible of the business logic and communicating results to the Presenter
- Presenter layer: from the Presenter, which provides the final formatted info to a passive
Viewfrom a UI element (fragments / activities). Finally, this information would be passed through the UI thread.
- This code test uses a wide range of Material design widgets from the Design support library such as:
AppBarLayout,CoordinatorLayout,Toolbar,RecyclerViewas well as Material theme styles.
- At the main screen a list of products which can be bought with their code, name and price
- Once clicked an item, the product is added to the list, and a toast is shown if correctly added
- For checking out and seeing the total basket price, click on the FAB button, this provides a final amount with discounts on it
- The repository contains cached information (RAM) for making an easy check out of the shopping list at any time
- For removing a previous shopping list (cached one), you need to entirely close the app, then the cache is clean
- Error handling integrated for
HttporConnectionorIOissues, also empty state indicating no results when required. - A Loader is placed each time a new request is started, to indicate the user the fact that there is an action going on
- There is a small amount of Unit test cases for the most critical parts: mainly the strategy for discounts as well as repository applying of its strategy (unit tests).
- Discount 1: Applied in 2-for-1 promotions (buy two of the same product, get one free), and would like for there to be a 2-for-1 special on VOUCHER items.
- Discount 2: For bulk purchases (buying x or more of a product, the price of that product is reduced), and demands that if you buy 3 or more TSHIRT items, the price per unit should be 19.00€.
Support SDKs from 16 to 25
- Dagger 2 for Dependency Injection
- ButterKnife v6.1.0 for Views Injection
- Retrofit 2 v2.1.0 for Network requests
- OkHttp 3 v3.6.0 as client for Retrofit
- Timber v4.1.2 for logs in debug mode only
- Mockito for Mocking artifacts
- JUnit for Unit tests
References (special thanks) - those are the same I indicated at my personal blog (Insights and projects):
- Uncle Bob: The Clean Architecture by Uncle Bob
- The Repository pattern by Microsoft
- Effective Android UI by Pedro Gomez
- Android Clean Architecture by Fernando Cejas
Please read first CONTRIBUTING
Raul Hernandez Lopez,
Copyright (C) 2017 Raul Hernandez Lopez
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.