Extending core block blueprints

[ovenum]

Description

When extending Kirbys core image block it’s not possible to limit the ratio options.

testBlocks:
  type: blocks
  fieldsets:
    image:
      extends: blocks/image
      fields:
        ratio:
          options:
            1/1: "1:1"
            16/9: "16:9"
            7/5: "7:5"

Expected behavior

The only options for the ratio should be the ones passed from the blueprint. (1/1, 16/9, 7/5)

As described in the cook book recipe Modifying blocks types and custom blocks / Extending existing fields it should be possible to limit the options.

Your setup

Kirby Version
3.7.2.1

Additional context

The difference between the example given in cook book recipe and the one above is the use of an non-associative array for the level options in the recipe and a associative array for ratio options.

[…]
fieldsets: 
  heading:
    extends: blocks/heading
    fields:
      level:
        # non-associative array, does overwrite the core block options
        options:
          - h2
          - h3
  image:
    extends: blocks/image
    fields:
      ratio:
        # associative array, does not overwrite the core block options
        options:
          1/1: "1:1"
          16/9: "16:9"
          7/5: "7:5"   

This is probably the only possible behaviour? Kirby/Cms/Blueprint,php:210 is merging the core blocks blueprint settings with the extension by calling A::merge($mixin, $props, A::MERGE_REPLACE). With A::MERGE_REPLACE only non-associative arrays will be replaced, so it’s not possible to remove keys from an associative array and that’s what you want 99.9% of the time when using extends with blueprints.

Maybe the cook book recipe should make a note of this?