Filter List (Facet)
FacetFilterListConnector( facetFilters: [FacetFilter], selectionMode: SelectionMode, filterState: FilterState, operator: RefinementOperator, groupName: String, controller: FilterListTableController<Filter.Facet> )
About this widget
FacetFiltersList is a filtering component that displays facet filters and lets the user refine the search results by selecting them.
Compared to the RefinementList, which takes its values from the search response facets, this widget displays facet filters that you add yourself.
Examples
Instantiate a FacetFilterListConnector and launch an initial search on its Searcher.
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let searcher: SingleIndexSearcher = SingleIndexSearcher(appID: "YourApplicationID",
apiKey: "YourSearchOnlyAPIKey",
indexName: "YourIndexName")
let filterState = FilterState()
let filters: [Filter.Facet] = ["red", "blue", "green", "yellow", "black"].map {
.init(attribute: "color", stringValue: $0)
}
let filterListTableView: UITableView = .init()
let filterListController: FilterListTableController<Filter.Facet> = .init(tableView: filterListTableView)
let filterListConnector = FacetFilterListConnector(facetFilters: filters,
selectionMode: .multiple,
filterState: filterState,
operator: .and,
groupName: "Facet Filters",
controller: filterListController)
searcher.connectFilterState(filterState)
searcher.search()
Parameters
facetFilters
|
type: [FacetFilter]
default: []
Required
The facet filters to display. |
selectionMode
|
type: SelectionMode
default: .multiple
Optional
Whether a user can select |
filterState
|
type: FilterState
Required
The |
operator
|
type: RefinementOperator
Required
Whether we apply an For example if we have an |
groupName
|
type: String
Required
Filter group name. |
controller
|
type: FilterListTableController<Filter.Facet>
default: nil
Optional
Controller interfacing with a concrete filter list view. |
Low-level API
If you want to fully control the FacetFilterList components and connect them manually, you can use the following components:
Searcher: TheSearcherthat handles your searches.FilterState: The current state of the filters.FacetFilterListInteractor: The logic applied to the facet filters.FilterListController: The view that will render the facet filters.
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let searcher: SingleIndexSearcher = SingleIndexSearcher(appID: "YourApplicationID",
apiKey: "YourSearchOnlyAPIKey",
indexName: "YourIndexName")
let filterState = FilterState()
let filters: [Filter.Facet] = ["red", "blue", "green", "yellow", "black"].map {
.init(attribute: "color", stringValue: $0)
}
let filterListTableView: UITableView = .init()
let filterListController: FilterListTableController<Filter.Facet> = .init(tableView: filterListTableView)
let filterListInteractor = FacetFilterListInteractor(items: filters, selectionMode: .multiple)
filterListInteractor.connectFilterState(filterState, operator: .and, groupName: "Facet Filters")
filterListInteractor.connectController(filterListController)
searcher.connectFilterState(filterState)
searcher.search()
Customizing your view
The controllers provided by default, e.g., FilterListTableController, work well when you want to use native UIKit components with their default behavior.
If you want to use another component such as a UICollectionView, a third-party input view, or you want to introduce some custom behavior to the already provided UIKit component, you can create your own controller conforming to the FacetFilterListController protocol.
Protocol
var onClick: ((Filter.Facet) -> Void)?:
Closure to call when a filter is clicked.
func setSelectableItems(selectableItems: [SelectableItem<Filter.Facet>])
Function called when a new array of selectable facets is updated. This is the UI State of the refinement list.
func reload()
Function called when we require a reload of the list view.
Example
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class FacetFilterListTableController: NSObject, FacetFilterListController, UITableViewDataSource, UITableViewDelegate {
public var onClick: ((Filter.Facet) -> Void)?
public let tableView: UITableView
public var selectableItems: [SelectableItem<Filter.Facet>] = []
public var filterPresenter: FilterPresenter?
let cellID: String
public init(tableView: UITableView, cellID: String = "cellID") {
self.tableView = tableView
self.cellID = cellID
super.init()
tableView.dataSource = self
tableView.delegate = self
tableView.register(UITableViewCell.self, forCellReuseIdentifier: cellID)
}
// MARK: - FilterListController
public func setSelectableItems(selectableItems: [SelectableItem<Filter.Facet>]) {
self.selectableItems = selectableItems
}
public func reload() {
tableView.reloadData()
}
// MARK: - UITableViewDataSource
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return selectableItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: cellID, for: indexPath)
let filter = selectableItems[indexPath.row]
let filterPresenter = self.filterPresenter ?? DefaultPresenter.Filter.present
cell.textLabel?.text = filterPresenter(Filter(filter.item))
cell.accessoryType = filter.isSelected ? .checkmark : .none
return cell
}
// MARK: - UITableViewDelegate
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let selectableItem = selectableItems[indexPath.row]
onClick?(selectableItem.item)
}
}
