Jsonschemaupdate from draft-04 to draft-07

[weblorin]

I noticed that draft-04 of the json schema specification isn't even listed on https://json-schema.org/specification/release-notes. I tried upgrading to latest version but the built-in VSCode validator wasn't fully compatible (it works but throws a warning which is annoying) . So upgrading to draft-07 is compromise. The following notes written with help of chatgpt4.1. - LSG

Subject: Specific Analysis of Migrating vector.schema.json from draft-04 to draft-07

Current Schema Features:

• The schema defines two main properties: legend (an array of string pairs) and layerStyles (an array of objects with required fields).
• The only syntax adjustment required is in the legend property:
  • In draft-04, tuple validation used "items": [{...}, {...}].
  • In draft-07, this is replaced by "prefixItems": [{...}, {...}] with "minItems": 2, "maxItems": 2 for strict length enforcement.

Are We Using New Features?

• No new draft-07 features (like if/then/else, const, or new formats) are used in this schema.
• The schema remains simple and compatible with both drafts, except for the tuple validation syntax.

Benefits of Changing from items to prefixItems with minItems and maxItems:

• Clarity: The intent is clearer—each array in legend must have exactly two strings.
• Spec Compliance: prefixItems is the recommended way to specify tuple validation in draft-07 and later, making the schema future-proof.
• Validation Strictness: Using minItems and maxItems ensures arrays are exactly the expected length, reducing the risk of malformed data.

Impact on Existing JSON Files:

• No impact. Existing files that were valid under draft-04 remain valid under draft-07, as the structure and requirements are unchanged.

Summary of Syntax Adjustments:

• Update $schema to draft-07.
• Replace array form of items with prefixItems and add minItems/maxItems for tuple validation in legend.
• No changes needed for layerStyles.