RD-1317: Add heatmap layer (#220)

Author: sasaprodribaba

Sources/MapTilerSDK/Commands/Style/AddLayer.swift

@@ -25,6 +25,8 @@ package struct AddLayer: MTCommand {
             return handleMTHillshadeLayer(layer)
         } else if let layer = layer as? MTCircleLayer {
             return handleMTCircleLayer(layer)
+        } else if let layer = layer as? MTHeatmapLayer {
+            return handleMTHeatmapLayer(layer)
         }
 
         return emptyReturnValue
@@ -106,6 +108,19 @@ package struct AddLayer: MTCommand {
         }
         return js
     }
+
+    private func handleMTHeatmapLayer(_ layer: MTHeatmapLayer) -> JSString {
+        guard let layerString: JSString = layer.toJSON() else {
+            return emptyReturnValue
+        }
+
+        let processed = unquoteExpressions(in: layerString)
+        var js = "\(MTBridge.mapObject).addLayer(\(processed));"
+        if let filter = layer.initialFilter {
+            js.append("\n \(MTBridge.mapObject).setFilter('\(layer.identifier)', \(filter.toJS()));")
+        }
+        return js
+    }
 }
 /// Replaces string-encoded expressions with raw JSON arrays.
 /// Ensures the style parser reads them as expressions (not strings).
@@ -126,6 +141,31 @@ fileprivate func unquoteExpressions(in json: String) -> String {
         with: "$1$2",
         options: .regularExpression
     )
+    s = s.replacingOccurrences(
+        of: #"(?s)("heatmap-color"\s*:\s*)"(\[.*?\])""#,
+        with: "$1$2",
+        options: .regularExpression
+    )
+    s = s.replacingOccurrences(
+        of: #"(?s)("heatmap-radius"\s*:\s*)"(\[.*?\])""#,
+        with: "$1$2",
+        options: .regularExpression
+    )
+    s = s.replacingOccurrences(
+        of: #"(?s)("heatmap-intensity"\s*:\s*)"(\[.*?\])""#,
+        with: "$1$2",
+        options: .regularExpression
+    )
+    s = s.replacingOccurrences(
+        of: #"(?s)("heatmap-opacity"\s*:\s*)"(\[.*?\])""#,
+        with: "$1$2",
+        options: .regularExpression
+    )
+    s = s.replacingOccurrences(
+        of: #"(?s)("heatmap-weight"\s*:\s*)"(\[.*?\])""#,
+        with: "$1$2",
+        options: .regularExpression
+    )
     // Unescape escaped quotes inside expression arrays (e.g., \"step\" -> "step")
     s = s.replacingOccurrences(of: "\\\"", with: "\"")
     return s

Sources/MapTilerSDK/Commands/Style/AddLayers.swift

@@ -30,6 +30,8 @@ package struct AddLayers: MTCommand {
                 jsString.append(handleMTHillshadeLayer(layer))
             } else if let layer = layer as? MTCircleLayer {
                 jsString.append(handleMTCircleLayer(layer))
+            } else if let layer = layer as? MTHeatmapLayer {
+                jsString.append(handleMTHeatmapLayer(layer))
             }
         }
 
@@ -107,6 +109,18 @@ package struct AddLayers: MTCommand {
         }
         return js
     }
+
+    private func handleMTHeatmapLayer(_ layer: MTHeatmapLayer) -> JSString {
+        guard let layerString: JSString = layer.toJSON() else {
+            return emptyReturnValue
+        }
+        let processed = unquoteExpressions(in: layerString)
+        var js = "\(MTBridge.mapObject).addLayer(\(processed));"
+        if let filter = layer.initialFilter {
+            js.append("\n \(MTBridge.mapObject).setFilter('\(layer.identifier)', \(filter.toJS()));")
+        }
+        return js
+    }
 }
 
 /// Replaces string-encoded expressions with raw JSON arrays.
@@ -128,6 +142,31 @@ fileprivate func unquoteExpressions(in json: String) -> String {
         with: "$1$2",
         options: .regularExpression
     )
+    s = s.replacingOccurrences(
+        of: #"(?s)("heatmap-color"\s*:\s*)"(\[.*?\])""#,
+        with: "$1$2",
+        options: .regularExpression
+    )
+    s = s.replacingOccurrences(
+        of: #"(?s)("heatmap-radius"\s*:\s*)"(\[.*?\])""#,
+        with: "$1$2",
+        options: .regularExpression
+    )
+    s = s.replacingOccurrences(
+        of: #"(?s)("heatmap-intensity"\s*:\s*)"(\[.*?\])""#,
+        with: "$1$2",
+        options: .regularExpression
+    )
+    s = s.replacingOccurrences(
+        of: #"(?s)("heatmap-opacity"\s*:\s*)"(\[.*?\])""#,
+        with: "$1$2",
+        options: .regularExpression
+    )
+    s = s.replacingOccurrences(
+        of: #"(?s)("heatmap-weight"\s*:\s*)"(\[.*?\])""#,
+        with: "$1$2",
+        options: .regularExpression
+    )
     s = s.replacingOccurrences(of: "\\\"", with: "\"")
     return s
 }

Sources/MapTilerSDK/Map/Style/Layer/Heatmap/MTHeatmapLayer+DSL.swift

@@ -0,0 +1,38 @@
+//
+// Copyright (c) 2026, MapTiler
+// All rights reserved.
+// SPDX-License-Identifier: BSD 3-Clause
+//
+//  MTHeatmapLayer+DSL.swift
+//  MapTilerSDK
+//
+
+import Foundation
+
+// DSL
+extension MTHeatmapLayer {
+    /// Adds layer to map DSL style.
+    ///
+    /// Prefer `MTStyle/addLayer(_:)` on MTMapView instead.
+    public func addToMap(_ mapView: MTMapView) {
+        Task {
+            let layer = MTHeatmapLayer(
+                identifier: self.identifier,
+                sourceIdentifier: self.sourceIdentifier,
+                maxZoom: self.maxZoom,
+                minZoom: self.minZoom,
+                sourceLayer: self.sourceLayer,
+                color: self.color,
+                intensity: self.intensity,
+                opacity: self.opacity,
+                radius: self.radius,
+                weight: self.weight,
+                visibility: self.visibility
+            )
+            layer.filterExpression = self.filterExpression
+            layer.initialFilter = self.initialFilter
+
+            try await mapView.style?.addLayer(layer)
+        }
+    }
+}