Adding dotNotation property and test

src/prop_tests/dotNotation_test.js

@@ -0,0 +1,31 @@
+var QUnit = require("steal-qunit");
+
+var set = require('../set-core'),
+  props = require("../props");
+
+QUnit.module("can-set props.boolean");
+
+/*
+ * For the dotNotation prop, we define sets like so:
+ *
+ * For a property 'n.p', with value 'IL'
+ * x ∈ X | x.n.p = 'IL'
+ *
+ */
+test('dotNotation set membership', function() {
+  /*
+   * For a property 'n.p', with value 'IL'
+   * x ∈ X | x.n.p == 'IL'
+   */
+  var prop = props.dotNotation('n.p'),
+      alg = new set.Algebra(prop),
+      res = alg.has({'n.p': 'IL'}, {n:{p:'IL'}});
+  ok(res, "object with nested property is member of set using dotNotation");
+
+  /*
+   * For a property 'n.p', with value 'IL'
+   * x ∉ X | x.n.p != 'IL'
+   */
+  res = alg.has({'n.p': 'IL'}, {n:{p:'MI'}});
+  ok(res === false, "object with nested property not a member of set using dotNotation");
+});

src/props.js

@@ -483,4 +483,55 @@ props.rangeInclusive = function(startIndexProperty, endIndexProperty){
 		});
 };
 
+var nestedLookup = function(obj, propNameArray) {
+	if (obj === undefined) {
+		return undefined;
+	}
+
+	if (propNameArray.length === 1) {
+		return obj[propNameArray[0]];
+	} else {
+		return nestedLookup(obj[propNameArray[0]], propNameArray.slice(1));
+	}
+};
+/**
+ * @function can-set.props.dotNotation dotNotation
+ * @parent can-set.props
+ *
+ * @description Supports MongoDB-style 'dot notation' properties.
+ *
+ * @signature `set.props.dotNotation(dotProperty)`
+ *
+ * Defines a property that specifies a MongoDB-style nested property match.
+ * For example, a set property of "address.city" matches against the value of the nested `{address: {city}}` value.
+ *
+ * ```
+ * set.props.dotNotation("address.city")
+ * ```
+ *
+ *   @param  {String} dotProperty The MongoDB-style nested property name
+ *   @return {can-set.compares} Returns a comparator used to build a set algebra
+ */
+props.dotNotation = function(dotProperty){
+	var compares = new clause.Where({});
+
+	compares[dotProperty] = function(aVal, bVal, a, b, propertyName) {
+		var modelVal, propertyVal;
+
+		// one of the value arguments being defined implies its the can-set definition prop, since a set member itself wont
+		// have obj['nested.property.name'] defined
+		if (aVal !== undefined) {
+			propertyVal = aVal;
+			modelVal = nestedLookup(b, propertyName.split('.'));
+		} else if (bVal !== undefined) {
+			propertyVal = bVal;
+			modelVal = nestedLookup(a, propertyName.split('.'));
+		}
+
+		return propertyVal === modelVal;
+	};
+
+	return compares;
+};
+
 module.exports = props;

src/props_test.js

@@ -7,3 +7,4 @@ require('./prop_tests/rangeInclusive_test');
 require('./prop_tests/offsetLimit_test');
 require('./prop_tests/boolean_test');
 require('./prop_tests/enum_test');
+require('./prop_tests/dotNotation_test');