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YAML and JSON Support for 2Pack (PackOut / PackIn)

The 2Pack packaging system (PackOut / PackIn) has historically only supported XML as its serialization format. This feature adds JSON and YAML as peer export/import formats, giving users the choice of a more human-readable and version-control-friendly output.

What Changed​

AspectBeforeAfter
Export formatsXML onlyXML, JSON, or YAML
Import detectionLooks for PackOut.xmlAuto-detects PackOut.xml, PackOut.json, or PackOut.yaml
Process parameterNoneNew Export Format parameter on PackOut process
Default formatN/AXML (unchanged — backward compatible)

Architecture​

A new IPackSerializer interface decouples PackOut from the SAX/XML pipeline, enabling pluggable serialization backends:

  • SAXPackSerializer — Adapter wrapping the existing XML path. Zero behavior change; all existing XML output is produced through this adapter.
  • JacksonPackSerializer (base) + JsonPackSerializer + YamlPackSerializer — Jackson-based serializers that convert pack events to nested JSON/YAML structures using _children arrays for nested elements.
  • DataPackInReader — Replays JSON/YAML as SAX events into the existing PackInHandler, so all import handler logic works unchanged regardless of the source format.
  • All ElementHandler implementations have been refactored to use IPackSerializer instead of TransformerHandler, but their behavior remains identical for XML exports.

Exporting a Package in JSON or YAML​

  1. Run the PackOut process as usual.
  2. In the new Export Format parameter, select:
    • X — XML (default, backward compatible)
    • J — JSON
    • Y — YAML
  3. The process generates the corresponding file (PackOut.xml, PackOut.json, or PackOut.yaml) in the package directory.

Importing a Package​

No configuration is needed. PackIn auto-detects the format by probing for PackOut.json, PackOut.yaml, and PackOut.xml in that order. If the package was exported in JSON or YAML, DataPackInReader routes it through the same PackInHandler used by XML imports.

The PipoDictionaryService (OSGi bundle auto-install) also follows the same probing order when importing dictionary files.

Migration​

A database migration creates:

  • AD_Reference 200286 ("2Pack Export Format") with list values X / J / Y.
  • AD_Element and AD_Process_Para ExportFormat2Pack on the AD_PackOut process (ID 50004).

Dependencies​

jackson-dataformat-yaml and snakeyaml have been added to the target platform, OSGi manifest imports, and all relevant launch configurations.