FilterState class abstract interface

FilterState holds one or several filters, organized in groups. filters streams filters changes of added or removed filters, which will be applied to searches performed by the connected Searcher.

Create

The following is an example of creating and setting up a FilterState with different filters (facets, tags and numerical):

const authors = FilterGroupID('author', FilterOperator.or);
const genres = FilterGroupID('genres');
const numbers = FilterGroupID('numbers');

final filterState = FilterState()
  ..add(authors, [Filter.facet('author', 'Shakespeare')])
  ..add(genres, [Filter.tag('drama')])
  ..add(numbers, [Filter.range('rating', lowerBound: 3, upperBound: 5)])
  ..add(numbers, [Filter.comparison('price', NumericOperator.less, 50)]);

The code snippet above corresponds to the following SQL-like expression: (author:Shakespeare) AND (_tags:drama) AND (rating:3 TO 5 AND price < 50)

Update

FilterState can be updated using methods such as add, set and remove, each modification triggers a filters submission.

Running multiple modifications (atomically), and trigger a single filters submission can be done using modify method:

  filterState.modify((filters) async =>
      filters
          .add(authors, [Filter.facet('author', 'J. K. Rowling')])
          .remove(authors, [Filter.facet('author', 'Shakespeare')]));

Delete

Remove all or some filter groups using clear and clearExcept

  filterState.clear(); // removes all filter groups
  filterState.clear(authors); // clears filter group 'authors'
  filterState.clearExcept([authors]); // clears all filter groups except 'authors'

Implemented types

Disposable

Constructors

FilterState(): FilterState's factory.
factory

Properties

filters → Stream<Filters>: Filters groups stream (facet, tag, numeric and hierarchical).
no setter
hashCode → int: The hash code for this object.
no setterinherited
isDisposed → bool: Whether this Disposable has already released its resources.
no setterinherited
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

add(FilterGroupID groupID, Iterable<Filter> filters) → void: Adds filters to the provided groupID.
addHierarchical(String attribute, HierarchicalFilter hierarchicalFilter) → void: Adds hierarchicalFilter to given attribute.
clear([Iterable<FilterGroupID>? groupIDs]) → void: Clears groupIDs. If none provided, all filters will be cleared.
clearExcept(Iterable<FilterGroupID> groupIDs) → void: Clears all except groupIDs.
contains(FilterGroupID groupID, Filter filter) → bool: Checks if filter exists in groupID.
dispose() → void: Releases this Disposable resources.
inherited
modify(AsyncFiltersBuilder builder) → Future<void>: Asynchronous updates filters by applying builder to current filters value. Useful to apply multiple consecutive update operations without firing multiple filters events.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
remove(FilterGroupID groupID, Iterable<Filter> filters) → void: Removes filters from groupID.
removeHierarchical(String attribute) → void: Removes HierarchicalFilter of given attribute.
set(Map<FilterGroupID, Set<Filter>> map) → void: Overrides filters with the provided map.
snapshot() → Filters: Get current filters value.
toggle(FilterGroupID groupID, Filter filter) → void: Toggles filter in given groupID.
toString() → String: A string representation of this object.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited