Class SearchViewModel

Backing controller for a search experience, intended for use with SearchView. SearchView supports searching, with search-as-you-type for multiple search providers via ISearchSource.

Inheritance

Object

SearchViewModel

Implements

INotifyPropertyChanged

Namespace: Esri.ArcGISRuntime.Toolkit.Maui

Assembly: Esri.ArcGISRuntime.Toolkit.Maui.dll

Syntax

public class SearchViewModel : INotifyPropertyChanged

Properties

ActivePlaceholder

Gets the correct placeholder to display in the UI.

Declaration

public string ActivePlaceholder { get; }

Property Value

Type	Description
String

ActiveSource

Gets or sets the active search source, if one is selected. If there is no selection, all sources will be used for the search.

Declaration

public ISearchSource ActiveSource { get; set; }

Property Value

Type	Description
ISearchSource

CurrentQuery

Gets or sets the current query.

Declaration

public string CurrentQuery { get; set; }

Property Value

Type	Description
String

Remarks

Call UpdateSuggestions() to refresh suggestions after updating the query.

DefaultPlaceholder

Gets or sets the default placeholder to use when there is no ActiveSource or the ActiveSource does not have a placeholder defined. Consumers should always display the ActivePlaceholder in the UI, rather than accessing this property directly.

Declaration

public string DefaultPlaceholder { get; set; }

Property Value

Type	Description
String

IgnoreAreaChangesFlag

Gets or sets a value indicating whether changes to the query area should be ignored. This is used to prevent IsEligibleForRequery becoming true because the view zoomed to a result.

Declaration

public bool IgnoreAreaChangesFlag { get; set; }

Property Value

Type	Description
Boolean

Remarks

Set this value to true when the GeoView is being navigated to show results, and set to false when the navigation completes.

IsEligibleForRequery

Gets a value indicating whether spatial parameters have changed enough to justify displaying a 'Repeat Search Here' button.

Declaration

public bool IsEligibleForRequery { get; }

Property Value

Type	Description
Boolean

Remarks

'Repeat Search Here' is a common pattern in applications that return multiple search results.

IsSearchInProgress

Gets a value indicating whether a search operation is in progress.

Declaration

public bool IsSearchInProgress { get; }

Property Value

Type	Description
Boolean

IsSuggestInProgress

Gets a value indicating whether a suggestion request is in progress.

Declaration

public bool IsSuggestInProgress { get; }

Property Value

Type	Description
Boolean

IsWaiting

Gets a value indicating whether a waiting operation (search, suggestion) is in progress.

Declaration

public bool IsWaiting { get; }

Property Value

Type	Description
Boolean

Remarks

This can be used to implement activity indicator or progress bar display.

QueryArea

Gets or sets the query area to use when searching and getting suggestions. When used in conjunction with a GeoView, this property should be set every time navigation completes, to enable automatic update of the IsEligibleForRequery property.

Declaration

public Geometry.Geometry? QueryArea { get; set; }

Property Value

Type	Description
Nullable<Geometry.Geometry>

QueryCenter

Gets or sets the center point around which results should be returned.

Declaration

public MapPoint? QueryCenter { get; set; }

Property Value

Type	Description
Nullable<MapPoint>

Results

Gets the list of search results for the most-recently completed query. Clearing a search via ClearSearch() will set this collection to null.

Declaration

public IList<SearchResult> Results { get; }

Property Value

Type	Description
IList<SearchResult>

SearchMode

Gets or sets the search mode, which defaults to Automatic. This mode controls how many results are displayed when a search is performed.

Declaration

public SearchResultMode SearchMode { get; set; }

Property Value

Type	Description
SearchResultMode

SelectedResult

Gets or sets the selected search result.

Declaration

public SearchResult SelectedResult { get; set; }

Property Value

Type	Description
SearchResult

Sources

Gets or sets the list of available search sources, which can be updated dynamically.

Declaration

public IList<ISearchSource> Sources { get; set; }

Property Value

Type	Description
IList<ISearchSource>

Remarks

See ConfigureDefaultWorldGeocoder(CancellationToken) for a convenient method to populate this collection automatically.

Suggestions

Gets the list of search suggestions. This value is set after calls to UpdateSuggestions().

Declaration

public IList<SearchSuggestion> Suggestions { get; }

Property Value

Type	Description
IList<SearchSuggestion>

Methods

AcceptSuggestion(SearchSuggestion)

Initiates a search using a suggestion as the query.

Declaration

public async Task AcceptSuggestion(SearchSuggestion suggestion)

Parameters

Type	Name	Description
SearchSuggestion	suggestion	A suggestion from Suggestions to be used as basis for the search.

Returns

Type	Description
Task

Remarks

This will update CurrentQuery to match the selected suggestion.

CancelSearch()

Cancels any active search task.

Declaration

public void CancelSearch()

CancelSuggestion()

Cancels any active suggest task.

Declaration

public void CancelSuggestion()

ClearSearch()

Cancels any active search/suggest tasks, then clears all results and the current query.

Declaration

public void ClearSearch()

CommitSearch()

Submits the current query as a fresh search.

Declaration

public async Task CommitSearch()

Returns

Type	Description
Task

Remarks

The search will return results from the ActiveSource or all Sources if ActiveSource is null. Search in progress can be cancelled by calling CancelSearch().

ConfigureDefaultWorldGeocoder(CancellationToken)

Configures the viewmodel with a search source optimized for use with the Esri World Geocoder service.

Declaration

public async Task ConfigureDefaultWorldGeocoder(CancellationToken token = default(CancellationToken))

Parameters

Type	Name	Description
CancellationToken	token	Token used for cancellation.

Returns

Type	Description
Task

RepeatSearchHere()

Repeats the current search, with results confined to the area defined by QueryArea.

Declaration

public async Task RepeatSearchHere()

Returns

Type	Description
Task

Remarks

This is used to allow users to narrow down search results using a geographic constraint. This is especially useful when a search results in multiple results.

UpdateSuggestions()

Updates Suggestions for the current query.

Declaration

public async Task UpdateSuggestions()

Returns

Type	Description
Task

Events

PropertyChanged

Declaration

public event PropertyChangedEventHandler PropertyChanged

Event Type

Type	Description
PropertyChangedEventHandler

Implements

INotifyPropertyChanged