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Migration Guide — From 0.20.x to 0.21.03

This guide explains how to migrate existing applications from DaaS-IoT 0.20.x to version 0.21.03.

The focus is on concrete code-level changes, based on real examples, and on behavioral differences that directly affect application logic.

Overview

Version 0.21.03 introduces several breaking changes affecting:

  • Event handler interfaces
  • DDO construction and handling
  • Identifier and timestamp management
  • Runtime responsibilities

Applications built for 0.20.x must be adapted to function correctly on 0.21.03.

1. Event Handler API Changes

What Changed

Event callback method names have been standardized.

Before (0.20.x)

def dinAcceptedEvent(self, din):
    ...

def ddoReceivedEvent(self, payload_size, typeset, din):
    ...

After (0.21.03)

def dinAccepted(self, din):
    ...

def ddoReceived(self, payload_size, typeset, din):
    ...

Impact

  • Old handler method names are no longer invoked
  • Applications must rename event callbacks to match the new API

2. DDO Origin and Timestamp Handling

What Changed

In version 0.21.03:

  • DDO origin is automatically assigned by the runtime
  • Applications can no longer manually set the origin or timestamp

Before (0.20.x)

ddo = pydaasiot.DDO()
ddo.setOrigin(origin_din)
ddo.setTypeset(typeset)

After (0.21.03)

ddo = pydaasiot.DDO()
ddo.setTypeset(typeset)

Impact

  • Calls to setOrigin() must be removed
  • Timestamp handling is no longer exposed at application level
  • This guarantees consistency with synchronization and routing

3. Payload Handling Changes

What Changed

Payload extraction is now handled through the runtime rather than directly through the DDO object.

Before (0.20.x)

raw = ddo.payload_text()

After (0.21.03)

payload = node.ddoPayloadAsString(ddo)

Impact

  • Direct payload access methods on the DDO object should no longer be used
  • Runtime-managed access ensures safe decoding and consistency

4. Node Initialization and Configuration

What Changed

  • Configuration files are now optional
  • Nodes can be initialized with minimal parameters

Before (0.20.x)

node = pydaasiot.DaasWrapper(config_path, handler)

After (0.21.03)

node = pydaasiot.DaasWrapper(None, handler)

Impact

  • Existing configuration files may need to be reviewed
  • Applications relying on stored configuration must verify compatibility

5. DDO Construction and Sending

What Stayed the Same

The basic workflow for sending a DDO remains unchanged:

ddo = pydaasiot.DDO()
ddo.setTypeset(typeset)
ddo.allocatePayload(len(payload))
ddo.appendPayloadData(payload)
node.push(target_din, ddo)

What Changed

  • No origin or timestamp assignment
  • Payload-less DDOs are now supported

6. Runtime Execution Model

What Stayed the Same

The core execution model remains:

node.doPerform(pydaasiot.performs_mode_t.PERFORM_CORE_THREAD)

New Considerations

  • Synchronization is now mandatory before bidirectional communication
  • Some operations (e.g. locate) require active core execution

Applications using a threadless core must ensure periodic execution.

7. Known Migration Pitfalls

  • Old event names not triggered
    Ensure all event callbacks use the updated naming.

  • Manual origin or timestamp assignment
    These calls must be removed.

  • Self-targeted messaging
    Sending DDOs to the local node DIN is not supported in 0.21.03.

  • Discovery timing on low-end devices
    Initial discovery may require retries.

Summary Checklist

Before running on 0.21.03, verify that your application:

  • Uses updated event handler method names
  • Does not manually set DDO origin or timestamp
  • Uses runtime helpers for payload extraction
  • Handles mandatory synchronization implicitly
  • Does not rely on self-targeted messaging

Warning

This migration is mandatory. Applications built for 0.20.x will not work correctly on version 0.21.03 without the changes described above.