Getting Started with Interoperability On Python

Welcome to the guide on getting started with Interoperability Embedded Python. This document will walk you through the initial steps to set up and begin using Python in your interoperability projects.

Prerequisites

Before you begin, ensure you have the following:

• A working installation of InterSystems IRIS with Embedded Python configured
• Basic knowledge of Python programming

Setting Up the Virtual Environment

To begin, you will need to set up a virtual environment for your Python project. A virtual environment is a self-contained directory that contains a Python installation for a particular version of Python, as well as any additional packages you may need for your project.

To create a virtual environment, run the following command in your terminal:

python -m venv .venv

This will create a new directory called .venv in your project directory, which will contain the Python interpreter and any packages you install.

Next, activate the virtual environment by running the following command:

For Unix or MacOS:

source .venv/bin/activate

For Windows:

.venv\Scripts\activate

You should now see the name of your virtual environment in your terminal prompt, indicating that the virtual environment is active.

Installing Required Packages

With your virtual environment activated, you can now install any required packages for your project. To install a package, use the pip command followed by the package name. For example, to install the iris-pex-embedded-python package, run the following command:

pip install iris-pex-embedded-python

Init the application using the following command:

iop --init

This will install the package and any dependencies it requires.

Hello World

Now that you have set up your virtual environment and installed the required packages, you are ready to create your first Interoperability production using Python.

Create a Business Operation

For this, we will create an BusinessOperation that will take a message as input and will return a message as output. In between, it will just print "Hello World" in the logs.

To do this, let's create a new folder named hello_world.

mkdir hello_world

In this folder, create a new file named bo.py.

This file will contain the code of our business operation.

from iop import BusinessOperation

class MyBo(BusinessOperation):
    def on_message(self, request):
        self.log_info("Hello World")

Let's explain this code.

First, we import the BusinessOperation class from the iop module.

Then, we create a class named MyBo that inherits from BusinessOperation.

Finally, we override the on_message method. This method will be called when a message is received by the business operation.

Import this Business Operation in the framework

Now, we need to add this business operation to what we call a production.

To do this, we will create a new file in the hello_world folder, named settings.py.

Every project starts at it's root folder by a file named settings.py.

This file contains two main settings:

• CLASSES : it contains the classes that will be used in the project.
• PRODUCTIONS : it contains the name of the production that will be used in the project.

from hello_world.bo import MyBo

CLASSES = {
    "MyIRIS.MyBo": MyBo
}

PRODUCTIONS = [
        {
            'MyIRIS.Production': {
                "@TestingEnabled": "true",
                "Item": [
                    {
                        "@Name": "Instance.Of.MyBo",
                        "@ClassName": "MyIRIS.MyBo",
                    }
                ]
            }
        } 
    ]

In this file, we import our MyBo class named in iris MyIRIS.MyBo, and we add it to the CLASSES dictionnary.

Then, we add a new production to the PRODUCTIONS list. This production will contain our MyBo class instance named Instance.Of.MyBo.

With the iop command, we can now create the production in IRIS.

iop --migrate /path/to/hello_world/settings.py

This command will create the production in IRIS and add the MyBo class to it.

More information about registering components can be found here.