Rule Loading & Ranking
On application initialization:
- 1.Built-in
WidgetsRules.ossrules are loaded. Build-in rules are already precompiled and are part of the @ngx-metaui/rules - 2.
- 3.If global application rule exists the
Application.ossthen its loaded insideValueQueriedObserverand there can only be one for the entire application. - 4.On first reference to class name in the MetaUI context:
- Introspection rules are created and they are loaded from
app/rules/[EntityNamne].oss
Application code can call
Meta APIs to programmatically load rules files or register rules.
- Matching rules are applied in rank order to build the property map.
- Rules from system (default rules) have lowest rank, then introspection rules, then application rules.
- Rank is (roughly) the order of appearance in the .oss file (later == higher rank)
- When multiple rules update the same property, type and key-specific merge rules are applied:
- Maps and trait lists are merged
- visible, editable, and valid expressions are chained with AND semantics (except if override value is used -
e.g. visible=true!) - Other values are overridden