[FirebaseAI] Add usage of Grounding with Google Search

firebaseai/ChatExample/Models/ChatMessage.swift

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+import FirebaseAI
 import Foundation
 
 enum Participant {
@@ -22,12 +23,19 @@ enum Participant {
 struct ChatMessage: Identifiable, Equatable {
   let id = UUID().uuidString
   var message: String
+  var groundingMetadata: GroundingMetadata?
   let participant: Participant
   var pending = false
 
   static func pending(participant: Participant) -> ChatMessage {
     Self(message: "", participant: participant, pending: true)
   }
+
+  // TODO(andrewheard): Add Equatable conformance to GroundingMetadata and remove this
+  static func == (lhs: ChatMessage, rhs: ChatMessage) -> Bool {
+    lhs.id == rhs.id && lhs.message == rhs.message && lhs.participant == rhs.participant && lhs
+      .pending == rhs.pending
+  }
 }
 
 extension ChatMessage {

firebaseai/ChatExample/Screens/ConversationScreen.swift

@@ -18,15 +18,22 @@ import SwiftUI
 
 struct ConversationScreen: View {
   let firebaseService: FirebaseAI
+  let title: String
   @StateObject var viewModel: ConversationViewModel
 
   @State
   private var userPrompt = ""
 
-  init(firebaseService: FirebaseAI) {
+  init(firebaseService: FirebaseAI, title: String, searchGroundingEnabled: Bool = false) {
+    let model = firebaseService.generativeModel(
+      modelName: "gemini-2.0-flash-001",
+      tools: searchGroundingEnabled ? [.googleSearch()] : []
+    )
+    self.title = title
     self.firebaseService = firebaseService
     _viewModel =
-      StateObject(wrappedValue: ConversationViewModel(firebaseService: firebaseService))
+      StateObject(wrappedValue: ConversationViewModel(firebaseService: firebaseService,
+                                                      model: model))
   }
 
   enum FocusedField: Hashable {
@@ -88,7 +95,7 @@ struct ConversationScreen: View {
         }
       }
     }
-    .navigationTitle("Chat example")
+    .navigationTitle(title)
     .onAppear {
       focusedField = .message
     }
@@ -123,7 +130,7 @@ struct ConversationScreen_Previews: PreviewProvider {
       .firebaseAI()) // Example service init
 
     var body: some View {
-      ConversationScreen(firebaseService: FirebaseAI.firebaseAI())
+      ConversationScreen(firebaseService: FirebaseAI.firebaseAI(), title: "Chat sample")
         .onAppear {
           viewModel.messages = ChatMessage.samples
         }
@@ -132,7 +139,7 @@ struct ConversationScreen_Previews: PreviewProvider {
 
   static var previews: some View {
     NavigationStack {
-      ConversationScreen(firebaseService: FirebaseAI.firebaseAI())
+      ConversationScreen(firebaseService: FirebaseAI.firebaseAI(), title: "Chat sample")
     }
   }
 }

firebaseai/ChatExample/ViewModels/ConversationViewModel.swift

@@ -35,9 +35,15 @@ class ConversationViewModel: ObservableObject {
 
   private var chatTask: Task<Void, Never>?
 
-  init(firebaseService: FirebaseAI) {
-    model = firebaseService.generativeModel(modelName: "gemini-2.0-flash-001")
-    chat = model.startChat()
+  init(firebaseService: FirebaseAI, model: GenerativeModel? = nil) {
+    if let model {
+      self.model = model
+    } else {
+      self.model = firebaseService.generativeModel(
+        modelName: "gemini-2.0-flash-001"
+      )
+    }
+    chat = self.model.startChat()
   }
 
   func sendMessage(_ text: String, streaming: Bool = true) async {
@@ -85,7 +91,14 @@ class ConversationViewModel: ObservableObject {
           if let text = chunk.text {
             messages[messages.count - 1].message += text
           }
+
+          if let candidate = chunk.candidates.first {
+            if let groundingMetadata = candidate.groundingMetadata {
+              self.messages[self.messages.count - 1].groundingMetadata = groundingMetadata
+            }
+          }
         }
+
       } catch {
         self.error = error
         print(error.localizedDescription)
@@ -119,6 +132,12 @@ class ConversationViewModel: ObservableObject {
           // replace pending message with backend response
           messages[messages.count - 1].message = responseText
           messages[messages.count - 1].pending = false
+
+          if let candidate = response?.candidates.first {
+            if let groundingMetadata = candidate.groundingMetadata {
+              self.messages[self.messages.count - 1].groundingMetadata = groundingMetadata
+            }
+          }
         }
       } catch {
         self.error = error

firebaseai/ChatExample/Views/Grounding/GoogleSearchSuggestionView.swift

@@ -0,0 +1,79 @@
+// Copyright 2025 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import SwiftUI
+import WebKit
+
+/// A view that renders Google Search suggestions with links that allow users
+/// to view the search results in the device's default browser.
+/// This is added to the bottom of chat messages containing results grounded
+/// in Google Search.
+struct GoogleSearchSuggestionView: UIViewRepresentable {
+  let htmlString: String
+
+  // This Coordinator class will act as the web view's navigation delegate.
+  class Coordinator: NSObject, WKNavigationDelegate {
+    func webView(_ webView: WKWebView,
+                 decidePolicyFor navigationAction: WKNavigationAction,
+                 decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
+      // Check if the navigation was triggered by a user clicking a link.
+      if navigationAction.navigationType == .linkActivated {
+        if let url = navigationAction.request.url {
+          // Open the URL in the system's default browser (e.g., Safari).
+          UIApplication.shared.open(url)
+        }
+        // Cancel the navigation inside our small web view.
+        decisionHandler(.cancel)
+        return
+      }
+      // For all other navigation types (like the initial HTML load), allow it.
+      decisionHandler(.allow)
+    }
+  }
+
+  func makeCoordinator() -> Coordinator {
+    Coordinator()
+  }
+
+  func makeUIView(context: Context) -> WKWebView {
+    let webView = WKWebView()
+    webView.isOpaque = false
+    webView.backgroundColor = .clear
+    webView.scrollView.backgroundColor = .clear
+    webView.scrollView.isScrollEnabled = false
+    // Set the coordinator as the navigation delegate.
+    webView.navigationDelegate = context.coordinator
+    return webView
+  }
+
+  func updateUIView(_ uiView: WKWebView, context: Context) {
+    // The renderedContent is an HTML snippet with CSS.
+    // For it to render correctly, we wrap it in a basic HTML document structure.
+    let fullHTML = """
+    <!DOCTYPE html>
+    <html>
+    <head>
+      <meta name='viewport' content='width=device-width, initial-scale=1.0, user-scalable=no'>
+      <style>
+        body { margin: 0; padding: 0; }
+      </style>
+    </head>
+    <body>
+      \(htmlString)
+    </body>
+    </html>
+    """
+    uiView.loadHTMLString(fullHTML, baseURL: nil)
+  }
+}

firebaseai/ChatExample/Views/Grounding/GroundedResponseView.swift

@@ -0,0 +1,81 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import FirebaseAI
+import SwiftUI
+
+/// A view that displays a chat message that is grounded in Google Search.
+struct GroundedResponseView: View {
+  var message: ChatMessage
+  var groundingMetadata: GroundingMetadata
+
+  var body: some View {
+    // We can only display a response grounded in Google Search if the searchEntrypoint is non-nil.
+    let isCompliant = (groundingMetadata.groundingChunks.isEmpty || groundingMetadata
+      .searchEntryPoint != nil)
+    if isCompliant {
+      HStack(alignment: .top, spacing: 8) {
+        VStack(alignment: .leading, spacing: 8) {
+          // Message text
+          ResponseTextView(message: message)
+
+          if !groundingMetadata.groundingChunks.isEmpty {
+            Divider()
+            // Source links
+            ForEach(0 ..< groundingMetadata.groundingChunks.count, id: \.self) { index in
+              if let webChunk = groundingMetadata.groundingChunks[index].web {
+                SourceLinkView(
+                  title: webChunk.title ?? "Untitled Source",
+                  uri: webChunk.uri
+                )
+              }
+            }
+          }
+          // Search suggestions
+          if let searchEntryPoint = groundingMetadata.searchEntryPoint {
+            Divider()
+            GoogleSearchSuggestionView(htmlString: searchEntryPoint.renderedContent)
+              .frame(height: 44)
+              .clipShape(RoundedRectangle(cornerRadius: 22))
+          }
+        }
+      }
+      .frame(maxWidth: .infinity, alignment: .leading)
+    }
+  }
+}
+
+/// A  view for a single, clickable source link.
+struct SourceLinkView: View {
+  let title: String
+  let uri: String?
+
+  var body: some View {
+    if let uri, let url = URL(string: uri) {
+      Link(destination: url) {
+        HStack(spacing: 4) {
+          Image(systemName: "link")
+            .font(.caption)
+            .foregroundColor(.secondary)
+          Text(title)
+            .font(.footnote)
+            .underline()
+            .lineLimit(1)
+            .multilineTextAlignment(.leading)
+        }
+      }
+      .buttonStyle(.plain)
+    }
+  }
+}

firebaseai/ChatExample/Views/MessageView.swift

@@ -14,6 +14,7 @@
 
 import MarkdownUI
 import SwiftUI
+import FirebaseAI
 
 struct RoundedCorner: Shape {
   var radius: CGFloat = .infinity
@@ -42,29 +43,43 @@ struct MessageContentView: View {
     if message.pending {
       BouncingDots()
     } else {
-      Markdown(message.message)
-        .markdownTextStyle {
-          FontFamilyVariant(.normal)
-          FontSize(.em(0.85))
-          ForegroundColor(message.participant == .system ? Color(UIColor.label) : .white)
-        }
-        .markdownBlockStyle(\.codeBlock) { configuration in
-          configuration.label
-            .relativeLineSpacing(.em(0.25))
-            .markdownTextStyle {
-              FontFamilyVariant(.monospaced)
-              FontSize(.em(0.85))
-              ForegroundColor(Color(.label))
-            }
-            .padding()
-            .background(Color(.secondarySystemBackground))
-            .clipShape(RoundedRectangle(cornerRadius: 8))
-            .markdownMargin(top: .zero, bottom: .em(0.8))
-        }
+      // Grounded Response
+      if let groundingMetadata = message.groundingMetadata {
+        GroundedResponseView(message: message, groundingMetadata: groundingMetadata)
+      } else {
+        // Non-grounded response
+        ResponseTextView(message: message)
+      }
     }
   }
 }
 
+struct ResponseTextView: View {
+  var message: ChatMessage
+
+  var body: some View {
+    Markdown(message.message)
+      .markdownTextStyle {
+        FontFamilyVariant(.normal)
+        FontSize(.em(0.85))
+        ForegroundColor(message.participant == .system ? Color(UIColor.label) : .white)
+      }
+      .markdownBlockStyle(\.codeBlock) { configuration in
+        configuration.label
+          .relativeLineSpacing(.em(0.25))
+          .markdownTextStyle {
+            FontFamilyVariant(.monospaced)
+            FontSize(.em(0.85))
+            ForegroundColor(Color(.label))
+          }
+          .padding()
+          .background(Color(.secondarySystemBackground))
+          .clipShape(RoundedRectangle(cornerRadius: 8))
+          .markdownMargin(top: .zero, bottom: .em(0.8))
+      }
+  }
+}
+
 struct MessageView: View {
   var message: ChatMessage