bairoliyaprem / ApiLogicServer

API Logic Server

There is widespread agreement that APIs are strategic to the business, required for mobile apps and internal / external systems integration.

The problem is that they are time-consuming and costly to develop. This reduces strategic business agility.

API Logic Server provides strategic business agility, by creating an executable server for a database, instantly.

An API Logic Server consists of 3 features:

Feature	Using	Providing
JSON:API and Swagger	SAFRS	Clients configure their own APIs to reduce network traffic
Transactional Logic	Logic Bank	Spreadsheet-like Rules are 40X more concise Compare Check Credit with legacy code
Basic Web App	Flask App Builder, fab-quickstart	Instant multi-page, multi-table web app for back-office admin, and prototyping

This declarative approach is based on standard Python tooling, and can be customized with standard approaches as described below.

Usage

Install with pip

Caution: Python install is rather more than running an installer. Use this page to Verify / Install Python. Then:

cd ~/Desktop
mkdir server
cd server
virtualenv venv
source venv/bin/activate
# windows venv\Scripts\activate
pip install ApiLogicServer

Quick Start - Create and Execute

Run the ApiLogicServer command line utility:

ApiLogicServer run  # you can also create, without execution

The db_url parameter defaults to a supplied sample database. Specify a SQLAlchemy url to use your own database.

The system operates as follows:

1. You run the ApiLogicServer utility

2. It creates a customizable api_server_project Project

3. It also runs the api_server_project, consisting of

   a. Your API, available in Swagger

   b. With underlying logic

   c. And a basic_web_app

Create (only)

You can also create the project, without execution:

ApiLogicServer create --project_name=my_api_logic_server

You may also wish to include the open_with parameter, to open an IDE or Editor on the created project. For example, PyCharm (charm) will open the project and create / initialize the venv automatically (some PyCharm configuration may be required):

ApiLogicServer create --project_name=my_api_logic_server db_url=sqlite:///nw.sqlite --open_with=charm

Execution

Once created, your api_logic_server project can be executed without creating.

With a proper virtual environment:

python api_logic_server_run.py
python ui/basic_web_app/run.py

Features

API: SAFRS JSON:API and Swagger

Your API is instantly ready to support ui and integration development, available in swagger:

Customize your API: edit api_logic_server_run.py, and see Customizing

Logic

Transactional business logic - multi-table derivations and constraints - are a significant portion of database systems, often nearly half. Procedural coding is time-consuming to develop and maintain, reducing business agility.

ApiLogicServer integrates Logic Bank, spreadsheet-like rules that reduce transaction logic by 40X. Logic is declared in Python (example below), and is:

• Extensible: logic consists of rules (see below), plus standard Python code

• Multi-table: rules like sum automate multi-table transactions

• Scalable: rules are pruned and optimized; for example, sums are processed as 1 row adjustment updates, rather than expensive SQL aggregate queries

• Manageable: develop and debug your rules in IDEs, manage it in SCS systems (such as git) using existing procedures

The following 5 rules represent the same logic as 200 lines of Python:

Declare your logic by editing: logic/logic_bank.py

Basic Web App - Flask Appbuilder

UI development takes time. That's a problem since

• Such effort may not be warranted for admin "back office" screens, and

• Agile approaches depend on getting working software soon, to drive collaboration and iteration.

ApiLogicServers therefore generate multi-page, multi-table applications as shown below:

1. Multi-page: apps include 1 page per table

2. Multi-table: pages include related_views for each related child table, and join in parent data

3. Favorite field first: first-displayed field is "name", or contains "name" (configurable)

4. Predictive joins: favorite field of each parent is shown (product name - not product id)

5. Ids last: such boring fields are not shown on lists, and at the end on other pages

Customize your app by editing: ui/basic_web_app/app/views.py

Status

Pre-Alpha / Technology Preview - just entering test.

Initially released 1/19/2021, the project is beginning to stablize. We have tested several sqlite databases, and several MySQL databases. These are both successfully creating the API and the web app.

The default Northwind project pre-creates logic, which is working with both the API and the web app.

We tracking issues in git.

Acknowledgements

Many thanks to

• Thomas Pollet, for SAFRS
• Daniel Gaspar, for Flask AppBuilder
• Achim Götz, for design collaboration

Articles

There a few articles that provide some orientation to Logic Bank and Flask App Builder. These technologies are automatically created when you use ApiLogicServer:

• Extensible Rules - defining new rule types, using Python
• Declarative - exploring multi-statement declarative technology
• Automate Business Logic With Logic Bank - general introduction, discussions of extensibility, manageability and scalability
• Agile Design Automation With Logic Bank - focuses on automation, design flexibility and agile iterations
• Instant Web Apps

Change Log

1.02.00 - Many:

1. Renamed logic/rules_bank to logic/logic_bank

2. Improved error handling on introspection failures

3. Building backrefs for relationships (with disambiguation)

4. Project creation defaults to copy (vs git clone)

5. Rules are pre-populated for the default (Northwind) database

1.01.02 - --host option, from_git supports local directory, hello world example

1.01.01 - Preliminary fixes for MySQL - acknowledgements (and thanks!) to Thomas Pollet

1.01.00 - use_model option, to use existing (manually repaired) model -- see Troubleshooting

1.0.9 - Run command

1.0.8 - Fix windows bug, options to specify clone-from and open-with

1.0.7 - Initial Version