diff options
Diffstat (limited to 'platform/darwin/src/MGLVectorStyleLayer.h')
| -rw-r--r-- | platform/darwin/src/MGLVectorStyleLayer.h | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/platform/darwin/src/MGLVectorStyleLayer.h b/platform/darwin/src/MGLVectorStyleLayer.h index 50e56d8643..d33494c3e4 100644 --- a/platform/darwin/src/MGLVectorStyleLayer.h +++ b/platform/darwin/src/MGLVectorStyleLayer.h @@ -59,7 +59,10 @@ NS_ASSUME_NONNULL_BEGIN <li><code>NSContainsPredicateOperatorType</code> (<code>CONTAINS</code>)</li> </ul> - To test whether a feature has or lacks a specific attribute, compare the attribute to `NULL` or `NIL`. Predicates created using the `+[NSPredicate predicateWithValue:]` method are also supported. String operators and custom operators are not supported. + To test whether a feature has or lacks a specific attribute, compare the + attribute to `NULL` or `NIL`. Predicates created using the + `+[NSPredicate predicateWithValue:]` method are also supported. String + operators and custom operators are not supported. For details about the predicate format string syntax, consult the “Predicate Format String Syntax” chapter of the @@ -130,8 +133,19 @@ NS_ASSUME_NONNULL_BEGIN style attributes and also `hyphen-minus` and `tag:subtag`. However, you must use `%K` in the format string to represent these variables: `@"%K == 'LineString'", @"$type"`. - - <!--EXAMPLE: MGLVectorStyleLayer.predicate--> + + ### Example + + To filter the layer to include only the features whose `index` attribute is 5 + or 10 and whose `ele` attribute is at least 1,500, you could create an + `NSCompoundPredicate` along these lines: + + ```swift + let layer = MGLLineStyleLayer(identifier: "contour", source: terrain) + layer.sourceLayerIdentifier = "contours" + layer.predicate = NSPredicate(format: "(index == 5 || index == 10) && ele >= 1500.0") + mapView.style.addLayer(layer) + ``` */ @property (nonatomic, nullable) NSPredicate *predicate; |