feat: Automatic nest new spans with the ui life cycle function

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Features
 
 - Add enableAutoBreadcrumbTracking option (#1958)
+- Automatic nest new spans with the ui life cycle function (#1959)
 
 ### Fixes
 

Samples/iOS-Swift/iOS-Swift/ViewControllers/LoremIpsumViewController.swift

@@ -19,5 +19,4 @@ class LoremIpsumViewController: UIViewController {
             }
         }
     }
-
 }

Sources/Sentry/SentryPerformanceTracker.m

@@ -13,7 +13,7 @@
 NS_ASSUME_NONNULL_BEGIN
 
 @interface
-SentryPerformanceTracker ()
+SentryPerformanceTracker () <SentryTracerDelegate>
 
 @property (nonatomic, strong) NSMutableDictionary<SentrySpanId *, id<SentrySpan>> *spans;
 @property (nonatomic, strong) NSMutableArray<id<SentrySpan>> *activeSpanStack;
@@ -67,6 +67,10 @@ - (SentrySpanId *)startSpanWithName:(NSString *)name operation:(NSString *)opera
                                                             bindToScope:bindToScope
                                                         waitForChildren:YES
                                                   customSamplingContext:@ {}];
+
+            if ([newSpan isKindOfClass:[SentryTracer class]]) {
+                [(SentryTracer *)newSpan setDelegate:self];
+            }
         }];
     }
 
@@ -179,6 +183,13 @@ - (BOOL)isSpanAlive:(SentrySpanId *)spanId
     }
 }
 
+- (nullable id<SentrySpan>)activeSpanForTracer:(SentryTracer *)tracer
+{
+    @synchronized(self.activeSpanStack) {
+        return [self.activeSpanStack lastObject];
+    }
+}
+
 @end
 
 NS_ASSUME_NONNULL_END

Sources/Sentry/SentryTracer.m

@@ -37,7 +37,6 @@
 SentryTracer ()
 
 @property (nonatomic, strong) SentrySpan *rootSpan;
-@property (nonatomic, strong) NSMutableArray<id<SentrySpan>> *children;
 @property (nonatomic, strong) SentryHub *hub;
 @property (nonatomic) SentrySpanStatus finishStatus;
 @property (nonatomic) BOOL isWaitingForChildren;
@@ -52,6 +51,7 @@ @implementation SentryTracer {
     NSMutableDictionary<NSString *, id> *_tags;
     NSMutableDictionary<NSString *, id> *_data;
     dispatch_block_t _idleTimeoutBlock;
+    NSMutableArray<id<SentrySpan>> *_children;
 
 #if SENTRY_HAS_UIKIT
     BOOL _startTimeChanged;
@@ -120,7 +120,7 @@ - (instancetype)initWithTransactionContext:(SentryTransactionContext *)transacti
     if (self = [super init]) {
         self.rootSpan = [[SentrySpan alloc] initWithTransaction:self context:transactionContext];
         self.name = transactionContext.name;
-        self.children = [[NSMutableArray alloc] init];
+        _children = [[NSMutableArray alloc] init];
         self.hub = hub;
         self.isWaitingForChildren = NO;
         _waitForChildren = waitForChildren;
@@ -194,15 +194,33 @@ - (void)cancelIdleTimeout
     }
 }
 
+- (id<SentrySpan>)getActiveSpan
+{
+    id<SentrySpan> span;
+
+    if (self.delegate) {
+        @synchronized(_children) {
+            span = [self.delegate activeSpanForTracer:self];
+            if (span == nil || span == self || ![_children containsObject:span]) {
+                span = _rootSpan;
+            }
+        }
+    } else {
+        span = _rootSpan;
+    }
+
+    return span;
+}
+
 - (id<SentrySpan>)startChildWithOperation:(NSString *)operation
 {
-    return [_rootSpan startChildWithOperation:operation];
+    return [[self getActiveSpan] startChildWithOperation:operation];
 }
 
 - (id<SentrySpan>)startChildWithOperation:(NSString *)operation
                               description:(nullable NSString *)description
 {
-    return [_rootSpan startChildWithOperation:operation description:description];
+    return [[self getActiveSpan] startChildWithOperation:operation description:description];
 }
 
 - (id<SentrySpan>)startChildWithParentId:(SentrySpanId *)parentId
@@ -220,7 +238,7 @@ - (void)cancelIdleTimeout
     context.spanDescription = description;
 
     SentrySpan *child = [[SentrySpan alloc] initWithTransaction:self context:context];
-    @synchronized(self.children) {
+    @synchronized(_children) {
         [_children addObject:child];
     }
 
@@ -298,6 +316,11 @@ - (BOOL)isFinished
     return self.rootSpan.isFinished;
 }
 
+- (NSArray<id<SentrySpan>> *)children
+{
+    return [_children copy];
+}
+
 - (void)setDataValue:(nullable id)value forKey:(NSString *)key
 {
     @synchronized(_data) {

Sources/Sentry/include/SentryTracer.h

@@ -4,10 +4,20 @@
 NS_ASSUME_NONNULL_BEGIN
 
 @class SentryHub, SentryTransactionContext, SentryTraceHeader, SentryTraceContext,
-    SentryDispatchQueueWrapper;
+    SentryDispatchQueueWrapper, SentryTracer;
 
 static NSTimeInterval const SentryTracerDefaultTimeout = 3.0;
 
+@protocol SentryTracerDelegate
+
+/**
+ * Return the active span of given tracer.
+ * This function is used to determine which span will be used to create a new child.
+ */
+- (nullable id<SentrySpan>)activeSpanForTracer:(SentryTracer *)tracer;
+
+@end
+
 @interface SentryTracer : NSObject <SentrySpan>
 
 /**
@@ -59,6 +69,11 @@ static NSTimeInterval const SentryTracerDefaultTimeout = 3.0;
  */
 @property (nonatomic, readonly) NSArray<id<SentrySpan>> *children;
 
+/*
+ * A delegate that provides extra information for the transaction.
+ */
+@property (nullable, nonatomic, weak) id<SentryTracerDelegate> delegate;
+
 /**
  * Init a SentryTracer with given transaction context and hub and set other fields by default
  *

Tests/SentryTests/Performance/SentryTracerTests.swift

@@ -2,6 +2,15 @@ import XCTest
 
 class SentryTracerTests: XCTestCase {
 
+    private class TracerDelegate: SentryTracerDelegate {
+
+        var activeSpan: Span?
+
+        func activeSpan(for tracer: SentryTracer) -> Span? {
+            return activeSpan
+        }
+    }
+
     private class Fixture {
         let client: TestClient
         let hub: TestHub
@@ -371,6 +380,53 @@ class SentryTracerTests: XCTestCase {
         assertAppStartsSpanAdded(transaction: transaction, startType: "Cold Start", operation: fixture.appStartColdOperation, appStartMeasurement: appStartMeasurement)
     }
 
+    func test_startChildWithDelegate() {
+        let delegate = TracerDelegate()
+
+        let sut = fixture.getSut()
+        sut.delegate = delegate
+
+        let child = sut.startChild(operation: fixture.transactionOperation)
+
+        delegate.activeSpan = child
+
+        let secondChild = sut.startChild(operation: fixture.transactionOperation)
+
+        XCTAssertEqual(secondChild.context.parentSpanId, child.context.spanId)
+    }
+
+    func test_startChildWithDelegate_ActiveNotChild() {
+        let delegate = TracerDelegate()
+
+        let sut = fixture.getSut()
+        sut.delegate = delegate
+
+        delegate.activeSpan = SentryTracer(transactionContext: TransactionContext(name: fixture.transactionName, operation: fixture.transactionOperation), hub: nil)
+
+        let child = sut.startChild(operation: fixture.transactionOperation)
+
+        let secondChild = sut.startChild(operation: fixture.transactionOperation)
+
+        XCTAssertEqual(secondChild.context.parentSpanId, sut.context.spanId)
+        XCTAssertEqual(secondChild.context.parentSpanId, child.context.parentSpanId)
+    }
+
+    func test_startChildWithDelegate_SelfIsActive() {
+        let delegate = TracerDelegate()
+
+        let sut = fixture.getSut()
+        sut.delegate = delegate
+
+        delegate.activeSpan = sut
+
+        let child = sut.startChild(operation: fixture.transactionOperation)
+
+        let secondChild = sut.startChild(operation: fixture.transactionOperation)
+
+        XCTAssertEqual(secondChild.context.parentSpanId, sut.context.spanId)
+        XCTAssertEqual(secondChild.context.parentSpanId, child.context.parentSpanId)
+    }
+
     func testAddWarmAppStartMeasurement_PutOnNextAutoUITransaction() {
         let appStartMeasurement = fixture.getAppStartMeasurement(type: .warm)
         SentrySDK.setAppStartMeasurement(appStartMeasurement)