Dynamic Facet List

Shows ordered facets and facet values based on index settings and rules.

Signature

DynamicFacetListConnector(
  searcher: Searcher,
  filterState: FilterState,
  orderedFacets: [AttributedFacets],
  selections: [Attribute: Set<String>],
  selectionModeForAttribute: [Attribute: SelectionMode],
  filterGroupForAttribute: [Attribute: FilterGroupDescriptor],
  controller: DynamicFacetListController
)

Explore example code

About this widget

DynamicFacetList is a view that displays the ordered list of facets and facet values. The order of groups and facet values in each group is defined by the corresponding index settings and applied index rules. You can configure the facet merchandising through the corresponding index setting. To learn more, see Facet display.

Requirements

You must set the attributes for faceting and configure the facet order, either using the dashboard or with the API parameters attributesForFaceting and renderingContent.

You must also set the facets property of the query with Searcher.request.query.facets and provide the facet attributes you want to retrieve.

You must use InstantSearch iOS v7.12.0 or later to use Dynamic Facet List.

Examples

Instantiate a DynamicFacetListConnector, set the query facets and launch an initial search on its searcher.

Swift

let searcher = HitsSeacher(appID: "YourApplicationID",
                           apiKey: "YourSearchOnlyAPIKey",
                           indexName: "YourIndexName")
searcher.request.query.facets = ["brand", "color", "size", "country"]

let filterState = FilterState()
let dynamicFacetListController = DynamicFacetListTableViewController()

let dynamicFacetlistConnector = DynamicFacetListConnector(searcher: searcher,
                                                          filterState: filterState,
                                                          selectionModeForAttribute: [
                                                            "color": .multiple,
                                                            "country": .multiple
                                                          ],
                                                          filterGroupForAttribute: [
                                                            "brand": ("brand", .or),
                                                            "color" : ("color", .or),
                                                          ],
                                                          controller: dynamicFacetListController)

searcher.connectFilterState(filterState)
searcher.search()

Parameters

searcher · Searcher · required

The Searcher that handles your searches.

filterState · FilterState · required

The FilterState that holds your filters.

orderedFacets · [AttributedFacets] · default: []

The ordered list of attributed facets.

selections · [Attribute: Set<String>] · default: []

The mapping between a facet attribute and a set of selected facet values.

selectionModeForAttribute · [Attribute: SelectionMode] · default: [:]

The mapping between a facet attribute and a facet values selection mode. If not provided, the default selection mode is .single.

filterGroupForAttribute · [Attribute: FilterGroupDescriptor] · default: [:]

The mapping between a facet attribute and a descriptor of a filter group where the corresponding facet filters are stored in the filter state.

controller · DynamicFacetListController

DynamicFacetListController implementation to connect.

Low-level API

If you want to fully control the DynamicFacetList components and connect them manually, you can use the following components:

• Searcher: the Searcher that handles your searches.
• FilterState: the current state of the filters.
• DynamicFacetListInteractor: dynamic facet list business logic
• DynamicFacetListController: controller presenting the ordered list of facets and handling the user interaction

Swift

let searcher = HitsSearcher(appID: "YourApplicationID",
                            apiKey: "YourSearchOnlyAPIKey",
                            indexName: "YourIndexName")
searcher.request.query.facets = ["brand", "color", "size", "country"]

let filterState = FilterState()
let dynamicFacetListController = DynamicFacetListTableViewController()

let dynamicFacetListInteractor = DynamicFacetListInteractor(selectionModeForAttribute: [
                                                              "color": .multiple,
                                                              "country": .multiple
                                                            ])

dynamicFacetListInteractor.connectSearcher(searcher)
dynamicFacetListInteractor.connectFilterState(filterState, filterGroupForAttribute: [
                                                             "brand": ("brand", .or),
                                                             "color" : ("color", .or),
                                                           ])
dynamicFacetListInteractor.connectController(dynamicFacetListController)

searcher.connectFilterState(filterState)
searcher.search()

Customizing your view

UIKit

InstantSearch iOS provides the DynamicFacetListTableViewController, which is the UITableViewController subclass that implements the DynamicFacetListController protocol. If you want to use another component, such as a UICollectionView or a third-party view, or if you want to introduce some custom behavior to the already provided UIKit component, you can create your own controller conforming to the DynamicFacetListController protocol.

Protocol

func setOrderedFacets(_ orderedFacets: [AttributedFacets]) Update the list of the ordered attributed facets

func setSelections(_ selections: [Attribute: Set<String>]) Update the facet selections

var didSelect: ((Attribute, Facet) -> Void)? Closure to trigger when user selects a facet

SwiftUI

InstantSearch iOS provides the DynamicFacetListObservableController, an implementation of the DynamicFacetListController protocol adapted for usage with SwiftUI. It provides orderedFacets and selections properties with convenient toggle and isSelected functions which let you implement your own SwiftUI view.

Implementation example

Swift

struct ContentView: View {

  @ObservedObject var dynamicFacetListController: DynamicFacetListObservableController

  var body: some View {
    ScrollView {
      ForEach(dynamicFacetListController.orderedFacets, id: \.attribute) { orderedFacet in
        VStack(spacing: 0) {
          // Facet header
          ZStack {
            Color(.systemGray5)
            Text(orderedFacet.attribute.rawValue)
              .fontWeight(.semibold)
              .frame(maxWidth: .infinity, alignment: .leading)
              .padding(.horizontal, 5)
          }
          // Facet values
          ForEach(orderedFacet.facets, id: \.value) { facet in
            VStack(spacing: 0) {
              FacetRow(facet: facet,
                      isSelected: dynamicFacetListController.isSelected(facet, for: orderedFacet.attribute))
                .onTapGesture {
                  dynamicFacetListController.toggle(facet, for: orderedFacet.attribute)
                }
                .frame(minHeight: 44, idealHeight: 44, maxHeight: .infinity, alignment: .center)
                .padding(.horizontal, 5)
            }
          }
        }
      }
    }
  }
}