Custom Handlers¶

You can easily create your own custom handlers by extending the BasePythonChangeHandler class.

Creating a Handler¶

You only need to implement the handleJsonBatch method. This method receives a list of ChangeEvent objects.

from typing import List
from pydbzengine import ChangeEvent, BasePythonChangeHandler

class MyCustomHandler(BasePythonChangeHandler):
    def handleJsonBatch(self, records: List[ChangeEvent]):
        print(f"Received batch of {len(records)} records")
        for record in records:
            # Access event data
            dest = record.destination()
            key = record.key()
            value = record.value()

            # Implement your logic here (e.g., push to Kafka, call API, etc.)
            print(f"Processing event for {dest}")

The ChangeEvent Object¶

The ChangeEvent object mimics the Debezium event model and provides the following Python methods to access event payload elements:

destination() -> str: Returns the destination topic or table name (e.g. inventory.customers).
key() -> str: Returns the JSON string representing the event's primary key(s) (e.g. '{"id": 1001}').
value() -> str: Returns the JSON string representing the CDC event payload (e.g. contains before, after, op, and source elements).
partition() -> int: Returns the partition number the event belongs to.