Phase 9-D: I/O integration for JSON Schema v2

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Summary

Integrate JSON Schema v2 I/O with the existing import/export operators.

Background

Updated 2026-01-13: The approach has changed per #89 decision.

• Dataclass schemas are NOT required (pm.data + ParsedData suffices)
• Focus on converter/serializer using existing infrastructure

Current State

• core/schema.py - SchemaProp, ParsedData for pm.data access
• infra/compat.py - PME1 → PME2 migration (fix_2_0_0, fix_json_2_0_0)
• api/validation.py - JSON validation API (stub, PR feat(api): enhance pme public API with types submodule and structured modules #99)

Tasks

Import Integration

• Modify WM_OT_pm_import to use infra/compat.py migration
• Add v1/v2 format auto-detection (see validation.py W301 warning)
• Show conversion warnings to user

Export Integration

• Modify WM_OT_pm_export to support v2 format
• Add export format selection UI (v1/v2)
• Implement PMItem → JSON v2 dict conversion

Validation API (PR #99)

• Implement full validation in api/validation.py
  • Currently stub: only format detection and basic checks
  • Need: field validation, reference checking per ERROR_CODES

Serializer Module

• Create infra/serializer.py for high-level export/import
• export_v2() - Export menus to PME2 JSON dict
• import_json() - Import with auto-detection and migration

Related

• Schema v2: PME1 to PME2 converter #83 - PME1 converter (partial in infra/compat.py)
• Phase 9-X: Internal Implementation Strategy - pm.data as settings carrier #89 - pm.data strategy (CLOSED - decided: no dataclass schemas)
• feat(api): enhance pme public API with types submodule and structured modules #99 - API enhancements including validation.py stub

Files

File	Purpose
operators/io.py	Import/export operators
infra/io.py	File I/O utilities
infra/compat.py	Migration functions
api/validation.py	JSON validation (stub)

Notes

This is the main work remaining for 2.0.0 JSON Schema v2 support:

• Users can export in new v2 format
• Importing v1 files auto-converts to v2 internally
• Round-trip (export v2 → import) is fully supported
• pme.validate_json() provides pre-import validation

Out of Scope (2.0.1+)

Per #89 decision:

• Dataclass schemas (core/schemas/) - NOT needed
• Complex WM_OT state machine redesign

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Status Update (2026-01-13)

Prerequisites Completed

• ✅ Phase 9-D Post-mortem: I/O Integration Issues #88: Post-mortem issues resolved
• ✅ Phase 9-X: Internal Implementation Strategy - pm.data as settings carrier #89: pm.data strategy confirmed
• ✅ Phase 9-X: Implement uid field for PMItem #93: uid field implemented
• ✅ feat(extend): ExtendManager with direct property binding UI #98: ExtendManager (extend_target in pm.data)
• ✅ fix(property): separate prop_type from poll_cmd (9-D-1) #94: PROPERTY mode fix (prop_type separated)

Ready to Proceed

Blocking issues resolved. This is now the primary remaining work for 2.0.0 JSON Schema v2.

Dependencies

• Schema v2: Implement dataclass schemas #84 (dataclass schemas) - Can work in parallel
• Schema v2: PME1 to PME2 converter #83 (PME1 converter) - Partially done in infra/compat.py

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Update: PR #99 adds validation API stub

PR #99 introduces api/validation.py with:

• pme.validate_json() - top-level validation function
• pme.validation.validate() - detailed validation
• pme.validation.validate_file() - file-based validation
• ValidationResult, ValidationIssue types

Current implementation status: Stub

• Format detection (PME1 list, PME1 dict, PME2 with $schema)
• W301 warning for PME1 format
• Basic structure checks

Not yet implemented:

• Full field validation per ERROR_CODES
• Menu uid reference checking
• All E3xx/E4xx/E5xx error codes

This stub provides the API surface; full implementation is part of this issue's scope.