[ios] added debug code, switch string to expression

3 files changed, 36 insertions, 13 deletions

diff --git a/platform/darwin/src/MGLShapeSource.h b/platform/darwin/src/MGLShapeSource.h
index 967fb94544..94e443b549 100644
--- a/platform/darwin/src/MGLShapeSource.h
+++ b/platform/darwin/src/MGLShapeSource.h
@@ -42,14 +42,20 @@ FOUNDATION_EXTERN MGL_EXPORT const MGLShapeSourceOption MGLShapeSourceOptionClus
 FOUNDATION_EXTERN MGL_EXPORT const MGLShapeSourceOption MGLShapeSourceOptionClusterRadius;
 
 /**
- An `NSDictionary` object where the key is an `NSString`. The dictionary key will be the attribute feature attribute key. The resulting attribute value is aggregated from the clustered points. The dictionary value is an `NSArray` consisting of a reduce operator and a map expression.
+ An `NSDictionary` object where the key is an `NSString`. The dictionary key will
+ be the attribute feature attribute key. The resulting attribute value is
+ aggregated from the clustered points. The dictionary value is an `NSArray`
+ consisting of two objects.
 
- The reduce operator is any `NSExpression` function that accepts at least two operands. You can use one of the following:
+ The first object determines how the attributes are accumulated from the cluster
+ points. You can use one of the following:
 
- * An `NSString` containing a single function, such as `sum` or `max`.
- * An `NSExpression` that takes two expression arguments: `featureAccumulated` and another valid expression.
+ * An `[NSExpression expressionForConstantValue:]` containing a single function string, such as `sum:` or `max:`, which takes at least two operands.
+ * An `NSExpression` that takes two expression arguments: `featureAccumulated` and
+ another valid expression.
 
- The map expression is an `NSExpression` that produces the value of a single point within the cluster.
+ The second object in the array is an `NSExpression` that produces the value of a
+ single point within the cluster.
 
  This option corresponds to the
  <a href="https://www.mapbox.com/mapbox-gl-style-spec/#sources-geojson-clusterProperties"><code>clusterProperties</code></a>
diff --git a/platform/darwin/src/MGLShapeSource.mm b/platform/darwin/src/MGLShapeSource.mm
index 00641c4a93..8bf0a3d3e5 100644
--- a/platform/darwin/src/MGLShapeSource.mm
+++ b/platform/darwin/src/MGLShapeSource.mm
@@ -108,20 +108,20 @@ mbgl::style::GeoJSONOptions MGLGeoJSONOptionsFromDictionary(NSDictionary<MGLShap
             }
 
             // reduceExpression could be either a string of operator, or a valid NSExpression
-            NSString *reduceOperator = expressionsArray[0];
+            if (![expressionsArray.firstObject isKindOfClass:[NSExpression class]]) {
+                [NSException raise:NSInvalidArgumentException
+                format:@"MGLShapeSourceOptionClusterProperties array value requires two expression objects."];
+            }
+            NSExpression *reduceOperator = expressionsArray[0];
             NSExpression *reduceExpression;
-            if ([reduceOperator isKindOfClass:[NSString class]]) {
+            if (reduceOperator.expressionType == NSConstantValueExpressionType) {
                 // If reduceOperator is a string, prepare a full NSExpression before parsing
-                NSString *reduceString = [NSString stringWithFormat:@"%@({ $featureAccumulated, %@})", reduceOperator, key];
+                NSString *reduceString = [NSString stringWithFormat:@"%@({ $featureAccumulated, %@})", reduceOperator.constantValue, key];
                 reduceExpression =  [NSExpression expressionWithFormat:reduceString];
             } else {
                 reduceExpression = expressionsArray[0];
             }
 
-            if (![reduceExpression isKindOfClass:[NSExpression class]]) {
-                [NSException raise:NSInvalidArgumentException
-                            format:@"MGLShapeSourceOptionClusterProperties member value shall contain a valid reduceExpression."];
-            }
             auto reduce = MGLClusterPropertyFromNSExpression(reduceExpression);
             if (!reduce) {
                 [NSException raise:NSInvalidArgumentException
@@ -132,7 +132,7 @@ mbgl::style::GeoJSONOptions MGLGeoJSONOptionsFromDictionary(NSDictionary<MGLShap
             NSExpression *mapExpression = expressionsArray[1];
             if (![mapExpression isKindOfClass:[NSExpression class]]) {
                 [NSException raise:NSInvalidArgumentException
-                            format:@"MGLShapeSourceOptionClusterProperties member value shall contain a valid mapExpression."];
+                            format:@"MGLShapeSourceOptionClusterProperties member value must contain a valid NSExpression."];
             }
             auto map = MGLClusterPropertyFromNSExpression(mapExpression);
             if (!map) {
diff --git a/platform/ios/app/MBXViewController.m b/platform/ios/app/MBXViewController.m
index 82a68e074a..cead3b4339 100644
--- a/platform/ios/app/MBXViewController.m
+++ b/platform/ios/app/MBXViewController.m
@@ -2202,6 +2202,23 @@ CLLocationCoordinate2D randomWorldCoordinate() {
     // that a device with an English-language locale is already effectively
     // using locale-based country labels.
     _localizingLabels = [[self bestLanguageForUser] isEqualToString:@"en"];
+
+    NSURL *url = [NSURL URLWithString:@"https://www.mapbox.com/mapbox-gl-js/assets/earthquakes.geojson"];
+
+    NSExpression *reduceExpression1 =  [NSExpression expressionWithFormat:@"sum:"];
+
+    NSExpression *mapExpression1 = [NSExpression expressionForKeyPath:@"mag"];
+    NSArray *expressArray1 = @[reduceExpression1, mapExpression1];
+
+    MGLShapeSource *source = [[MGLShapeSource alloc] initWithIdentifier:@"earthquakes" URL:url options:@{
+    MGLShapeSourceOptionClustered: @(YES),
+    MGLShapeSourceOptionClusterRadius: @(15),
+    MGLShapeSourceOptionClusterProperties: @{@"sumVal" : expressArray1 }}];
+    [mapView.style addSource:source];
+    MGLSymbolStyleLayer *clusterLayer = [[MGLSymbolStyleLayer alloc] initWithIdentifier:@"clusteredPortsNumbers" source:source];
+    clusterLayer.text = [NSExpression expressionWithFormat:@"CAST(sumVal, 'NSString')"];
+    [self.mapView.style addLayer:clusterLayer];
+
 }
 
 - (BOOL)mapView:(MGLMapView *)mapView shouldChangeFromCamera:(MGLMapCamera *)oldCamera toCamera:(MGLMapCamera *)newCamera {