Sample CodeiOS, iPadOS, Mac CatalystReviewed 2026-07-21View on Apple Developer

Logging symptoms associated with a medication

At a glance

Item Summary
Purpose Fetch medications and dose events from the HealthKit store, and create symptom samples to associate with them.
App architecture A Swift sample with the source-visible chain MedsSymptomsLoggingAppTabsViewHealthStoreDoseEventProviderHealthKit / HealthKitUI APIs.
Main patterns Central store, Binding-based state propagation, Actor-isolated state
Project style 23 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.

Project structure

Source bundle/
└── MedsSymptomsLoggingApp/
    ├── MedsSymptomsLoggingApp.swift
    ├── Views/
    │   ├── Charts/
    │   │   ├── MedicationChartsView+ChartsView.swift
    │   │   ├── MedicationChartsView.swift
    │   │   └── MedicationChartsView+MedicationSelectorView.swift
    │   ├── TabsView.swift
    │   └── HealthKitAuthorizationGatedView.swift
    ├── Models/
    │   ├── AnnotatedMedicationConceptModel.swift
    │   ├── DoseEventModel.swift
    │   ├── Stores/
    │   │   └── HealthStore.swift
    │   └── SymptomModel.swift
    └── Data Sources/
        ├── DoseEventProvider.swift
        └── MedicationProvider.swift

Structure observations

  • Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
  • Primary languages: Swift.
  • The verified tree contains 4 project/configuration file(s) and 27 source declaration(s).

Overall architecture

Reference code

MedsSymptomsLoggingApp/MedsSymptomsLoggingApp.swift:11 — architecture anchor

@main
struct MedsSymptomsLoggingApp: App {
    // ...
}

Interpretation

The arrows summarize the source-visible entry, role-named types or folders, and framework direction; when nodes come from structural folders, the sequence is a high-level interpretation rather than proof that every adjacent node calls the next. Ownership is claimed only where the next section cites a stored property or assignment. The diagram is intentionally limited to the dominant path into HealthKit.

Ownership and state

Ownership evidence

MedsSymptomsLoggingApp/MedsSymptomsLoggingApp.swift:15 — stored dependency or nearest verified ownership anchor

@main
struct MedsSymptomsLoggingApp: App {
    // ...
    @State var triggerMedicationsAuthorization: Bool = false
    // ...
}
Owner Object or state Relationship Mutation authority
MedsSymptomsLoggingApp Bool (triggerMedicationsAuthorization) owns wrapper-managed state App/module collaborators
MedsSymptomsLoggingApp Bool (healthDataAuthorized) owns wrapper-managed state App/module collaborators
ChartsView DateConfiguration (dateConfiguration) borrows mutable state The upstream binding owner is authoritative
ChartsView Array (chartSeries) owns value state Initialized by the owner; the binding is immutable

Composition arrows indicate a source-visible construction expression or locally owned value state; aggregation means the owner stores or receives a dependency without proving exclusive lifetime ownership.

Class and protocol design

MedsSymptomsLoggingApp/MedsSymptomsLoggingApp.swift:12 — representative type boundary

struct MedsSymptomsLoggingApp: App {
    // ...
}
Type Responsibility Depends on or conforms to
MedsSymptomsLoggingApp Application entry and top-level composition App
ChartsView User-interface presentation and input forwarding View
DateIntervalPaginationView User-interface presentation and input forwarding View
DoseEventModel Feature data or observable state Sendable, Identifiable, Equatable, Hashable
HealthStore Centralized state or persistence access Sendable
SymptomModel Feature data or observable state Sendable, Identifiable, Hashable
MedicationChartsView User-interface presentation and input forwarding View
TabsView User-interface presentation and input forwarding View
DoseEventProvider Supplies a capability or framework resource Sendable
MedicationProvider Supplies a capability or framework resource Concrete collaborators/imported frameworks

No local protocol conformance is claimed as protocol-oriented design; external framework conformances are listed only as dependencies.

Access control

Symbol Access Verified effect Likely rationale
doseEvents (MedsSymptomsLoggingApp/Data Sources/DoseEventProvider.swift:19) private(set) Read access follows the declaration; writes remain in the private scope. Inference: allow observation while reserving invariant-changing writes for the owner.
updatedDoseSampleCollection (MedsSymptomsLoggingApp/Data Sources/DoseEventProvider.swift:21) private(set) Read access follows the declaration; writes remain in the private scope. Inference: allow observation while reserving invariant-changing writes for the owner.
handleResultForLastLoggedDose (MedsSymptomsLoggingApp/Data Sources/DoseEventProvider.swift:146) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: hide an implementation step that is not part of the collaboration surface.
handleResult (MedsSymptomsLoggingApp/Data Sources/DoseEventProvider.swift:171) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: hide an implementation step that is not part of the collaboration surface.

Reference code

MedsSymptomsLoggingApp/Data Sources/DoseEventProvider.swift:19 — representative boundary

    private(set) var doseEvents: [DoseEventModel] = []

    private(set) var updatedDoseSampleCollection = [HKMedicationDoseEvent]()

    /// Creates a data source for providing `HKMedicationDoseEvent` samples for a provided `HKMedicationConcept`.
    init(healthStore: HKHealthStore,
         annotatedMedicationConcept: AnnotatedMedicationConcept) {
        // ...
    }

Swift declarations without a modifier are internal; explicit private, fileprivate, private(set), public, or open entries above are interpreted by language semantics. Objective-C/C samples instead rely on header and implementation boundaries, which are not equivalent to Swift lexical privacy.

Logic ownership and placement

Logic Owning type or file Placement rationale
Application entry and top-level composition MedsSymptomsLoggingApp The source’s App suffix makes this role explicit.
Feature data or observable state DoseEventModel, SymptomModel The source’s Model suffix makes this role explicit.
Supplies a capability or framework resource DoseEventProvider, MedicationProvider The source’s Provider suffix makes this role explicit.
Centralized state or persistence access HealthStore The source’s Store suffix makes this role explicit.
User-interface presentation and input forwarding ArchivedMedicationView, ChartsView, DateIntervalPaginationView, DoseEventView The source’s View suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
Central store MedsSymptomsLoggingApp/Models/Stores/HealthStore.swift:11 A store-named type centralizes feature state or persistence.
Binding-based state propagation MedsSymptomsLoggingApp/Views/Charts/MedicationChartsView+ChartsView.swift:16 A binding exposes controlled read/write access while the upstream owner remains authoritative.
Actor-isolated state MedsSymptomsLoggingApp/Data Sources/DoseEventProvider.swift:11 Actor annotations make the concurrency ownership boundary explicit.

Naming conventions

  • Types: App: MedsSymptomsLoggingApp; Model: DoseEventModel, SymptomModel; Provider: DoseEventProvider, MedicationProvider; Store: HealthStore; View: ArchivedMedicationView, ChartsView, DateIntervalPaginationView, DoseEventView, HealthKitAuthorizationGatedView.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: chartPoints, chartPoint, decrement, increment, todayView, calendarChartsView.
  • Files: MedsSymptomsLoggingApp/MedsSymptomsLoggingApp.swift, MedsSymptomsLoggingApp/Models/DoseEventModel.swift, MedsSymptomsLoggingApp/Models/Stores/HealthStore.swift, MedsSymptomsLoggingApp/Models/SymptomModel.swift, MedsSymptomsLoggingApp/Views/Charts/MedicationChartsView.swift, MedsSymptomsLoggingApp/Views/TabsView.swift.

Architecture takeaways

  • MedsSymptomsLoggingApp is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches SwiftUI, HealthKit, Charts, HealthKitUI through a deliberately small high-level chain; the detailed API graph remains inside the cited implementation files.
  • Stored-property evidence identifies lifecycle collaboration; it does not by itself prove exclusive object ownership.
  • Access-control conclusions separate verified language visibility from the likely design rationale.
  • The source does not justify labeling the design protocol-oriented.

Source map

Source file Relevant symbols
MedsSymptomsLoggingApp/MedsSymptomsLoggingApp.swift MedsSymptomsLoggingApp
MedsSymptomsLoggingApp/Views/Charts/MedicationChartsView+ChartsView.swift ChartsView, ChartSeries, ChartPoint, DateIntervalPaginationView
MedsSymptomsLoggingApp/Models/AnnotatedMedicationConceptModel.swift AnnotatedMedicationConcept
MedsSymptomsLoggingApp/Models/DoseEventModel.swift DoseEventModel
MedsSymptomsLoggingApp/Models/Stores/HealthStore.swift HealthStore
MedsSymptomsLoggingApp/Models/SymptomModel.swift SymptomModel
MedsSymptomsLoggingApp/Views/Charts/MedicationChartsView.swift MedicationChartsView, DateConfiguration
MedsSymptomsLoggingApp/Views/TabsView.swift TabsView, TabKind
MedsSymptomsLoggingApp/Data Sources/DoseEventProvider.swift DoseEventProvider
MedsSymptomsLoggingApp/Data Sources/MedicationProvider.swift MedicationProvider