Implement 'top tags' feature.

Examples/Reminders/ReminderForm.swift

@@ -57,7 +57,7 @@ struct ReminderFormView: View {
       }
       .popover(isPresented: $isPresentingTagsPopover) {
         NavigationStack {
-          TagsPopover(selectedTags: $selectedTags)
+          TagsView(selectedTags: $selectedTags)
         }
       }
 
@@ -185,45 +185,6 @@ extension Optional {
   }
 }
 
-struct TagsPopover: View {
-  @SharedReader(.fetchAll(sql: #"SELECT * FROM "tags" ORDER BY "name" ASC"#))
-  var availableTags: [Tag]
-
-  @Binding var selectedTags: [Tag]
-
-  @Environment(\.dismiss) var dismiss
-
-  var body: some View {
-    List {
-      let selectedTagIDs = Set(selectedTags.map(\.id))
-      ForEach(availableTags, id: \.id) { tag in
-        let tagIsSelected = selectedTagIDs.contains(tag.id)
-        Button {
-          if tagIsSelected {
-            selectedTags.removeAll(where: { $0.id == tag.id })
-          } else {
-            selectedTags.append(tag)
-          }
-        } label: {
-          HStack {
-            if tagIsSelected {
-              Image.init(systemName: "checkmark")
-            }
-            Text(tag.name)
-          }
-        }
-        .tint(tagIsSelected ? .blue : .black)
-      }
-    }
-    .toolbar {
-      ToolbarItem {
-        Button("Done") { dismiss() }
-      }
-    }
-    .navigationTitle(Text("Tags"))
-  }
-}
-
 #Preview {
   let (remindersList, reminder) = try! prepareDependencies {
     $0.defaultDatabase = try Reminders.appDatabase(inMemory: true)

Examples/Reminders/Schema.swift

@@ -215,10 +215,15 @@ func appDatabase(inMemory: Bool = false) throws -> any DatabaseWriter {
       _ = try Tag(name: "kids").inserted(self)
       _ = try Tag(name: "someday").inserted(self)
       _ = try Tag(name: "optional").inserted(self)
+      _ = try Tag(name: "social").inserted(self)
+      _ = try Tag(name: "night").inserted(self)
+      _ = try Tag(name: "adulting").inserted(self)
       _ = try ReminderTag(reminderID: 1, tagID: 3).inserted(self)
       _ = try ReminderTag(reminderID: 1, tagID: 4).inserted(self)
+      _ = try ReminderTag(reminderID: 1, tagID: 7).inserted(self)
       _ = try ReminderTag(reminderID: 2, tagID: 3).inserted(self)
       _ = try ReminderTag(reminderID: 2, tagID: 4).inserted(self)
+      _ = try ReminderTag(reminderID: 3, tagID: 7).inserted(self)
       _ = try ReminderTag(reminderID: 4, tagID: 1).inserted(self)
       _ = try ReminderTag(reminderID: 4, tagID: 2).inserted(self)
     }

Examples/Reminders/TagsForm.swift

@@ -0,0 +1,111 @@
+import SharingGRDB
+import SwiftUI
+
+struct TagsView: View {
+  @SharedReader(.fetch(Tags())) var tags = Tags.Value()
+  @Binding var selectedTags: [Tag]
+
+  @Environment(\.dismiss) var dismiss
+
+  var body: some View {
+    Form {
+      let selectedTagIDs = Set(selectedTags.map(\.id))
+      if !tags.top.isEmpty {
+        Section {
+          ForEach(tags.top, id: \.id) { tag in
+            TagView(
+              isSelected: selectedTagIDs.contains(tag.id),
+              selectedTags: $selectedTags,
+              tag: tag
+            )
+          }
+        } header: {
+          Text("Top tags")
+        }
+      }
+      if !tags.rest.isEmpty {
+        Section {
+          ForEach(tags.rest, id: \.id) { tag in
+            TagView(
+              isSelected: selectedTagIDs.contains(tag.id),
+              selectedTags: $selectedTags,
+              tag: tag
+            )
+          }
+        }
+      }
+    }
+    .toolbar {
+      ToolbarItem {
+        Button("Done") { dismiss() }
+      }
+    }
+    .navigationTitle(Text("Tags"))
+  }
+
+  struct Tags: FetchKeyRequest {
+    func fetch(_ db: Database) throws -> Value {
+      let top = try Tag.fetchAll(
+        db,
+        sql: """
+          SELECT "tags".*, count("reminders"."id")
+          FROM "tags"
+          LEFT JOIN "remindersTags" 
+            ON "tags"."id" = "remindersTags"."tagID"
+          LEFT JOIN "reminders" 
+            ON "remindersTags"."reminderID" = "reminders"."id"
+          GROUP BY "tags"."id"
+          HAVING count("reminders"."id") > 0
+          ORDER BY count("reminders"."id") DESC, "name"
+          LIMIT 3
+          """)
+      let rest = try Tag.fetchAll(
+        db,
+        SQLRequest(literal: """
+          SELECT "tags".*
+          FROM "tags"
+          WHERE "id" NOT IN \(top.compactMap(\.id))
+          ORDER BY "name"
+          """)
+      )
+      return Value(rest: rest, top: top)
+    }
+    struct Value {
+      var rest: [Tag] = []
+      var top: [Tag] = []
+    }
+  }
+}
+
+private struct TagView: View {
+  let isSelected: Bool
+  @Binding var selectedTags: [Tag]
+  let tag: Tag
+
+  var body: some View {
+    Button {
+      if isSelected {
+        selectedTags.removeAll(where: { $0.id == tag.id })
+      } else {
+        selectedTags.append(tag)
+      }
+    } label: {
+      HStack {
+        if isSelected {
+          Image.init(systemName: "checkmark")
+        }
+        Text(tag.name)
+      }
+    }
+    .tint(isSelected ? .blue : .black)
+  }
+}
+
+#Preview {
+  @Previewable @State var tags: [Tag] = []
+  let _ = prepareDependencies {
+    $0.defaultDatabase = try! Reminders.appDatabase(inMemory: true)
+  }
+
+  TagsView(selectedTags: $tags)
+}