Cache geometry

js/id/behavior/draw_way.js

@@ -1,6 +1,6 @@
 iD.behavior.DrawWay = function(context, wayId, index, mode, baseGraph) {
     var way = context.entity(wayId),
-        isArea = way.geometry() === 'area',
+        isArea = context.geometry(wayId) === 'area',
         finished = false,
         annotation = t((way.isDegenerate() ?
             'operations.start.annotation.' :

js/id/core/node.js

@@ -16,7 +16,9 @@ _.extend(iD.Node.prototype, {
     },
 
     geometry: function(graph) {
-        return graph.isPoi(this) ? 'point' : 'vertex';
+        return graph.transient(this, 'geometry', function() {
+            return graph.isPoi(this) ? 'point' : 'vertex';
+        });
     },
 
     move: function(loc) {

js/id/core/relation.js

@@ -25,8 +25,10 @@ _.extend(iD.Relation.prototype, {
         });
     },
 
-    geometry: function() {
-        return this.isMultipolygon() ? 'area' : 'relation';
+    geometry: function(graph) {
+        return graph.transient(this, 'geometry', function() {
+            return this.isMultipolygon() ? 'area' : 'relation';
+        });
     },
 
     // Return the first member with the given role. A copy of the member object

js/id/core/way.js

@@ -70,8 +70,10 @@ _.extend(iD.Way.prototype, {
         return false;
     },
 
-    geometry: function() {
-        return this.isArea() ? 'area' : 'line';
+    geometry: function(graph) {
+        return graph.transient(this, 'geometry', function() {
+            return this.isArea() ? 'area' : 'line';
+        });
     },
 
     addNode: function(id, index) {

js/id/operations/rotate.js

@@ -8,7 +8,7 @@ iD.operations.Rotate = function(selection, context) {
     operation.available = function() {
         return selection.length === 1 &&
             context.entity(entityId).type === 'way' &&
-            context.entity(entityId).geometry() === 'area';
+            context.geometry(entityId) === 'area';
     };
 
     operation.disabled = function() {

test/spec/core/relation.js

@@ -47,8 +47,12 @@ describe('iD.Relation', function () {
     });
 
     describe("#geometry", function () {
-        it("returns 'relation'", function () {
-            expect(iD.Relation().geometry()).to.equal('relation');
+        it("returns 'area' for multipolygons", function () {
+            expect(iD.Relation({tags: {type: 'multipolygon'}}).geometry(iD.Graph())).to.equal('area');
+        });
+
+        it("returns 'relation' for other relations", function () {
+            expect(iD.Relation().geometry(iD.Graph())).to.equal('relation');
         });
     });
 

test/spec/core/way.js

@@ -176,11 +176,11 @@ describe('iD.Way', function() {
 
     describe("#geometry", function() {
         it("returns 'line' when the way is not an area", function () {
-            expect(iD.Way().geometry()).to.equal('line');
+            expect(iD.Way().geometry(iD.Graph())).to.equal('line');
         });
 
         it("returns 'area' when the way is an area", function () {
-            expect(iD.Way({tags: { area: 'yes' }}).geometry()).to.equal('area');
+            expect(iD.Way({tags: { area: 'yes' }}).geometry(iD.Graph())).to.equal('area');
         });
     });