[ios, macos] Add aftermarket function to 'has' operator.

2 files changed, 36 insertions, 10 deletions

diff --git a/platform/darwin/src/NSExpression+MGLAdditions.mm b/platform/darwin/src/NSExpression+MGLAdditions.mm
index 4f5739aaa1..a5676529fc 100644
--- a/platform/darwin/src/NSExpression+MGLAdditions.mm
+++ b/platform/darwin/src/NSExpression+MGLAdditions.mm
@@ -61,6 +61,7 @@
     INSTALL_METHOD(mgl_interpolate:withCurveType:parameters:stops:);
     INSTALL_METHOD(mgl_step:from:stops:);
     INSTALL_METHOD(mgl_coalesce:);
+    INSTALL_METHOD(mgl_hasProperty:properties:);
     
     // Install functions that resemble control structures, taking arbitrary
     // numbers of arguments. Vararg aftermarket functions need to be declared
@@ -110,6 +111,15 @@
 }
 
 /**
+ A placeholder for a method that evaluates a coalesce expression.
+ */
+- (id)mgl_hasProperty:(id)element properties:(id)properties {
+    [NSException raise:NSInvalidArgumentException
+                format:@"Has expressions lack underlying Objective-C implementations."];
+    return nil;
+}
+
+/**
  A placeholder for a method that evaluates an expression based on an arbitrary
  number of variable names and assigned expressions.
  */
@@ -586,7 +596,8 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
             NSArray *subexpressions = MGLSubexpressionsWithJSONObjects(argumentObjects);
             NSExpression *operand = argumentObjects.count > 1 ? subexpressions[1] : [NSExpression expressionWithFormat:@"self"];
             NSExpression *property = subexpressions.firstObject;
-            return [NSExpression expressionWithFormat:@"FUNCTION(%@, 'mgl_has:', %@)", operand, property];
+            
+            return [NSExpression expressionForFunction:@"mgl_hasProperty:properties:" arguments:@[property, operand]];
         } else if ([op isEqualToString:@"interpolate"]) {
             NSArray *interpolationOptions = argumentObjects.firstObject;
             NSString *curveType = interpolationOptions.firstObject;
@@ -837,12 +848,9 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
                 return @[@"to-string", self.operand.mgl_jsonExpressionObject];
             } else if ([function isEqualToString:@"noindex:"]) {
                 return self.arguments.firstObject.mgl_jsonExpressionObject;
-            } else if ([function isEqualToString:@"mgl_has:"]) {
-                NSMutableArray *expressionObject = [NSMutableArray arrayWithObjects:@"has", self.arguments[0].mgl_jsonExpressionObject, nil];
-                if (self.operand.expressionType != NSEvaluatedObjectExpressionType) {
-                    [expressionObject addObject:self.operand.mgl_jsonExpressionObject];
-                }
-                return expressionObject;
+            } else if ([function isEqualToString:@"mgl_hasProperty:properties:"] ||
+                       [function isEqualToString:@"mgl_has:"]) {
+                return self.mgl_jsonHasExpressionObject;
             } else if ([function isEqualToString:@"mgl_interpolate:withCurveType:parameters:stops:"]
                        || [function isEqualToString:@"mgl_interpolateWithCurveType:parameters:stops:"]) {
                 return self.mgl_jsonInterpolationExpressionObject;
@@ -1066,4 +1074,17 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
     return expressionObject;
 }
 
+- (id)mgl_jsonHasExpressionObject {
+    BOOL isAftermarketFunction = [self.function isEqualToString:@"mgl_hasProperty:properties:"];
+    NSExpression *operand = isAftermarketFunction ? self.arguments[1] : self.operand;
+
+    NSMutableArray *expressionObject = [NSMutableArray arrayWithObjects:@"has", self.arguments[0].mgl_jsonExpressionObject, nil];
+    if (operand.expressionType != NSEvaluatedObjectExpressionType) {
+        [expressionObject addObject:operand.mgl_jsonExpressionObject];
+    }
+    return expressionObject;
+    
+    return expressionObject;
+}
+
 @end
diff --git a/platform/darwin/test/MGLExpressionTests.mm b/platform/darwin/test/MGLExpressionTests.mm
index 20209f305e..9c6a454943 100644
--- a/platform/darwin/test/MGLExpressionTests.mm
+++ b/platform/darwin/test/MGLExpressionTests.mm
@@ -718,19 +718,24 @@ using namespace std::string_literals;
         XCTAssertEqualObjects([NSExpression mgl_expressionWithJSONObject:jsonExpression], expression);
     }
     {
-        NSExpression *expression = [NSExpression expressionWithFormat:@"FUNCTION(self, 'mgl_has:', 'x')"];
+        NSExpression *expression = [NSExpression expressionForFunction:@"mgl_hasProperty:properties:" arguments:@[[NSExpression expressionForConstantValue:@"x"],
+                                                                                                                 [NSExpression expressionForEvaluatedObject]]];
+        NSExpression *compatibilityExpression = [NSExpression expressionWithFormat:@"FUNCTION(self, 'mgl_has:', 'x')"];
         NSArray *jsonExpression = @[@"has", @"x"];
         XCTAssertEqualObjects(expression.mgl_jsonExpressionObject, jsonExpression);
+        XCTAssertEqualObjects(compatibilityExpression.mgl_jsonExpressionObject, jsonExpression);
         XCTAssertEqualObjects([NSExpression mgl_expressionWithJSONObject:jsonExpression], expression);
     }
     {
-        NSExpression *expression = [NSExpression expressionWithFormat:@"FUNCTION(%@, 'mgl_has:', 'x')", [NSExpression expressionForConstantValue:@{@"x": MGLConstantExpression(@0)}]];
+        NSExpression *expression = [NSExpression expressionForFunction:@"mgl_hasProperty:properties:" arguments:@[[NSExpression expressionForConstantValue:@"x"],
+                                                                                                                  [NSExpression expressionForConstantValue:@{@"x": MGLConstantExpression(@0)}]]];
         NSArray *jsonExpression = @[@"has", @"x",  @[@"literal", @{@"x": @0}]];
         XCTAssertEqualObjects(expression.mgl_jsonExpressionObject, jsonExpression);
         XCTAssertEqualObjects([NSExpression mgl_expressionWithJSONObject:jsonExpression], expression);
     }
     {
-        NSExpression *expression = [NSExpression expressionWithFormat:@"FUNCTION($mgl_featureProperties, 'mgl_has:', 'x')"];
+        NSExpression *expression = [NSExpression expressionForFunction:@"mgl_hasProperty:properties:" arguments:@[[NSExpression expressionForConstantValue:@"x"],
+                                                                                                                  [NSExpression expressionForVariable:@"mgl_featureProperties"]]];
         NSArray *jsonExpression = @[@"has", @"x", @[@"properties"]];
         XCTAssertEqualObjects(expression.mgl_jsonExpressionObject, jsonExpression);
         XCTAssertEqualObjects([NSExpression mgl_expressionWithJSONObject:jsonExpression], expression);