support-semantic-search-with-core-spotlight.md

Support semantic search with Core Spotlight

Presenters: Jennifer Moore, Spotlight Engineer

Link: https://developer.apple.com/wwdc24/10131

• Framework that allows your app to donate searchable content to Spotlight

Provide content to the search index

• Donate searchable content to Spotlight that represents what people will want to search
• Index items in a way that can be retrieved from a query
• Semantic search works best on text and media
• Use system-defined attributes when possible

Creating CCSearchableItem

// Creating searchable items for donation
let item = CSSearchableItem(uniqueIdentifier: uniqueIdentifier, domainIdentifier: domainIdentifier, attributeSet: attributeSet)

Creating CCSearchableAttributeSet

// Creating searchable content for donation
let attributeSet = CSSearchableItemAttributeSet(contentType: UTType.text)
attributeSet.contentType = UTType.text.identifier

Searchable items with type

// Searchable items with text
attributeSet.title
attributeSet.textContent

// Searchable items with media
attributeSet.contentType
attributeSet.contentURL

// Searchable items with links
attributeSet.contentURL
attributeSet.relatedUniqueIdentifier

Indexing items

Batch indexing with client state

// Batch indexing with client state
let index = CSSearchableIndex(name: "SpotlightSearchSample")        
index.fetchLastClientState { state, error in         
    if state == nil {
        index.beginBatch()
        index.indexSearchableItems(items)
        index.endIndexBatch(expectedClientState: state, newClientState: newState) { error in
        }
    }
}

Avoid overwriting existing attributes

// Make it an update to avoid overwriting existing attributes
item.isUpdate = true

Configure a query

// Configure a query
let queryContext = CSUserQueryContext()
queryContext.fetchAttributes = ["title", "contentDescription"]

Ranked results

// Ranked results
queryContext.enableRankedResults = true
queryContext.maxRankedResultCount = 2

Suggestions

// Suggestions
queryContext.maxSuggestionCount = 4

Filter queries

// Filter queries
queryContext.filterQueries = ["contentTypeTree=\"public.image\""]

Query for searchable items and suggestions

// Query for searchable items and suggestions
let query = CSUserQuery(userQueryString: "windsurfing carmel", userQueryContext: queryContext)
for try await element in query.responses {
    switch(element) {
        case .item(let item):
            self.items.append(item)
            break
        case .suggestion(let suggestion):
            self.suggestions.append(suggestion)
            break
    }
}

Suggestions

// Suggestions
suggestion.localizedAttributedSuggestion

Preparing for queries

Models must be downloaded, so call this before search appears

// Preparing for queries
CSUserQuery.prepare
CSUserQuery.prepareWithProtectionClasses

Freshness signals for ranking

Set the lastUsedDate

// Set the lastUsedDate when the user interacts with the item
item.attributeSet.lastUsedDate = Date.now
item.isUpdate = true

Interactions with items and suggestions from a query

// Interactions with items and suggestions from a query
query.userEngaged(item, visibleItems: visibleItems, interaction: CSUserQuery.UserInteractionKind.select)
query.userEngaged(suggestion, visibleSuggestions: visibleSuggestions, interaction: CSUserQuery.UserInteractionKind.select)