feat: setFilter/getFilter for layers (#7)

* feat: setFilter/getFilter for layers

Author: KG3RK3N

src/filter/filter-parser.android.ts

@@ -0,0 +1,17 @@
+export class FilterParser {
+    static parseJson(json: any[]): com.mapbox.mapboxsdk.style.expressions.Expression {
+        const expression = com.mapbox.mapboxsdk.style.expressions.Expression.Converter.convert(JSON.stringify(json));
+        return expression;
+    }
+    static toJson(filter: com.mapbox.mapboxsdk.style.expressions.Expression): any[] {
+        if (!filter) {
+            return null;
+        }
+
+        if (!(filter instanceof com.mapbox.mapboxsdk.style.expressions.Expression)) {
+            throw new Error('Filter must be a Expression.');
+        }
+
+        return JSON.parse(filter.toString());
+    }
+}

src/filter/filter-parser.ios.ts

@@ -0,0 +1,26 @@
+export class FilterParser {
+    static parseJson(json: any[]): NSPredicate {
+        const filterStr = NSString.stringWithString(JSON.stringify(json));
+        const filterData = filterStr.dataUsingEncoding(NSUTF8StringEncoding);
+        const filterJson = NSJSONSerialization.JSONObjectWithDataOptionsError(filterData, NSJSONReadingOptions.MutableContainers);
+        const predicateFilter = (NSPredicate as any).predicateWithMGLJSONObject(filterJson);
+
+        return predicateFilter;
+    }
+
+    static toJson(filter: NSPredicate): any[] {
+        if (!filter) {
+            return null;
+        }
+
+        if (!(filter instanceof NSPredicate)) {
+            throw new Error('Filter must be a NSPredicate.');
+        }
+
+        const expressionObj = (filter as any).mgl_jsonExpressionObject;
+        const data = NSJSONSerialization.dataWithJSONObjectOptionsError(expressionObj, 0);
+        const expression: any = NSString.alloc().initWithDataEncoding(data, NSUTF8StringEncoding);
+
+        return JSON.parse(expression);
+    }
+}

src/mapbox.android.ts

@@ -8,6 +8,7 @@ import { request } from '@nativescript-community/perms';
 import { AndroidApplication, Application, Color, File, Trace, Utils, knownFolders, path } from '@nativescript/core';
 import { AndroidActivityBundleEventData, AndroidActivityEventData } from '@nativescript/core/application/application-interfaces';
 import { getImage } from '@nativescript/core/http';
+import { FilterParser } from './filter/filter-parser.android';
 import { GeoUtils } from './geo.utils';
 import {
     AddExtrusionOptions,
@@ -4282,6 +4283,14 @@ export class Layer implements LayerCommon {
     public hide(): void {
         this.instance.setProperties([new com.mapbox.mapboxsdk.style.layers.PropertyValue('visibility', 'none')]);
     }
+
+    public setFilter(filter: any[]) {
+        this.instance.setFilter(FilterParser.parseJson(filter));
+    }
+
+    public getFilter(): any[] {
+        return FilterParser.toJson(this.instance.getFilter());
+    }
 }
 
 // END

src/mapbox.common.ts

@@ -487,6 +487,8 @@ export interface LayerCommon {
     visibility(): boolean;
     show(): void;
     hide(): void;
+    setFilter(filter: any[]): void;
+    getFilter(): any[];
 }
 
 // ------------------------------------------------------------

src/mapbox.ios.ts

@@ -39,6 +39,7 @@ import {
 import { GeoUtils } from './geo.utils';
 import { iOSNativeHelper } from '@nativescript/core/utils';
 import { getImage } from '@nativescript/core/http';
+import { FilterParser } from './filter/filter-parser.ios';
 
 // Export the enums for devs not using TS
 
@@ -3561,5 +3562,19 @@ export class Layer implements LayerCommon {
     hide(): void {
         this.instance.visible = false;
     }
+
+    setFilter(filter: any[]) {
+        if (this.instance instanceof MGLVectorStyleLayer) {
+            // MGLVectorStyleLayer is the base type of many layer types. Predicates only supported on vector style layers.
+            // See https://docs.mapbox.com/ios/maps/api/6.3.0/Classes/MGLVectorStyleLayer.html
+
+            this.instance.predicate = FilterParser.parseJson(filter);
+        } else {
+            throw new Error('Set filter only support for vector layer.');
+        }
+    }
+
+    getFilter(): any[] {
+        return FilterParser.toJson(this.instance.predicate);
+    }
 }
-