Skip empty nodes at serialization

[jrodriguez-rc]

This new option will skip all the nodes that have no content:

• Simple node values empty/null
• Structures/Arrays with no subnodes

[sbcgua]

Do you mean without filter ? https://github.com/sbcgua/ajson#predefined-filters

Also:

• structures/arrays should be ok
• but values are not. Is false empty ? Or null ? Or 0. I think not always.

[mbtools]

I would go with the most famous isEmpty implementation:
https://github.com/lodash/lodash/blob/main/src/isEmpty.ts

It's working differently now:

ajson/src/libs/zcl_ajson_filter_lib.clas.locals_imp.abap

Lines 11 to 18 in 2504b31

	method zif_ajson_filter~keep_node.
	rv_keep = boolc(
	( iv_visit = zif_ajson_filter=>visit_type-value and is_node-value is not initial ) or
	( iv_visit <> zif_ajson_filter=>visit_type-value and is_node-children > 0 ) ).
	" children = 0 on open for initially empty nodes and on close for filtered ones
	endmethod.

I changed my custom empty filter to the following which also removes null and initial numbers (zero).

    rv_keep = boolc(
      ( iv_visit = zif_ajson_filter=>visit_type-value AND
        ( is_node-type = zif_ajson_types=>node_type-string AND is_node-value IS NOT INITIAL OR
          is_node-type = zif_ajson_types=>node_type-boolean OR
          is_node-type = zif_ajson_types=>node_type-number AND is_node-value <> 0 ) ) OR
      ( iv_visit <> zif_ajson_filter=>visit_type-value AND is_node-children > 0 ) ).