Examples

Examples

This folder contains some example applications demonstrating different functionality of SAFRS.

Basic Use Case

mini_app.py : a small sample application The example can be started with

PYTHONPATH=. FLASK_APP=mini_app flask run

Relationships

demo_relationship.py : an extension of the mini_app.py to demonstrate relationship functionality. Ex.:

python3 demo_relationship.py 172.16.9.12

Bigger Example

The demo_pythonanywhere_com.py example is deployed here. It demonstrates different functionalities that can be used. Ex.:

python3 demo_pythonanywhere_com.py 172.16.9.12

note, you may have to install the requirements.txt dependencies

Example without SQLAlchemy Model

The demo_stateless.py example demonstrates how to create an exposed object that is not based on an SQLAlchemy instance.

GeoAlchemy2 example

demo_geoalchemy.py

Expose Existing Databases:

It is possible to expose existing databases, as an example I implemented the employees and sakila MuySQL test databases with safrs.

For this to work, I used a modified sqlacodegen to generate the sqlalchemy models sakila.py and employees.py .

The Flask webservices are created with expose_sakila.py and expose_employees.py. They can be started as usual:

$ python3 examples/expose_employees.py 172.1.1.2 5000

Exposed sakila database:

Unfortunatley, the code generated with sqlacodegen needed some manual changes before it was usable. For example, the declarative column types for INTEGER and SMALLINT didn't work so I had to create small wrappers to fix this:

def SMALLINT(_):
    return db.SMALLINT

def INTEGER(_):
    return db.INTEGER

You may run into similar problems trying to expose other schemas. These problems may be hard to solve if you're unfamiliar with SQLAlchemy. Feel free to open a github issue and I'll try to help you out.