Relational Filter

[apstanisic]

Relational Filter

[wwwhttpru]

My solution to the problem was the following:
add in filter.dart

  const Filter.child(String value, Filter filter)
      : value = filter,
        comparison = value;

and
change toMapEntry method

  MapEntry<String, Object?> toMapEntry(String field) {
    // If value is a list of non filters
    if (value is List<Map<String, Filter>>) {
      if (comparison == '_or' || comparison == '_and') {
        return MapEntry(
          comparison,
          convertFilterList(value! as List<Map<String, Filter>>),
        );
      }
    }

    if (value != null && value is Filter) {
      final filter = value! as Filter;
      final childMap = filter.toMapEntry(comparison);
      return MapEntry(field, {
        childMap.key: childMap.value,
      });
    }

    return MapEntry(field, {comparison: value});
  }

[wwwhttpru]

Вот пример реализации в коде

final f = Filters(
      <String, Filter>{
        'author': Filter.child(
          'name',
          Filter.eq('Rijk van Zanten'),
        ),
      },
    );

result: f.toMap();

{author: {name: {_eq: Rijk van Zanten}}}

[apstanisic]

Maybe we can change Map<String, Filter> data; to Map<String, object>

directus-dart/lib/src/data_classes/filters.dart

Line 29 in 17ce3c8

Map<String, Filter> data;

Only problem is that with that way we lose some type safety, but user could then pass simple JSON.
Do you think it's to verbose having to type Filter.xxx for every comparison?

[wwwhttpru]

I have used my own class before and I don't think it's very safe.

abstract class ApiFilter {
  ApiFilter._();

  static Map<String, Object?> filterItem(
    String superFiled,
    Object items,
  ) {
    return <String, Object?>{
      superFiled: items,
    };
  }

  static Map<String, Object?> filterItems(List<Map<String, Object?>> items) {
    final map = <String, Object?>{};
    for (final item in items) {
      map.addAll(item);
    }
    return map;
  }

  /// Равно
  static const String eq = '_eq';

  /// Не равно
  static const String neq = '_neq';

  /// Меньше
  static const String lt = '_lt';

  /// Меньше или равно
  static const String lte = '_lte';
  ...
}

I don't see any difficulty in writing Filter.xxx
I am ready to consider different implementations, but I would like to do so that would not spoil the current api

[apstanisic]

Yeah, if you can create PR without breaking change, that would be awesome

[apstanisic]

Closed in #37