Merge pull request #44 from canjs/set-element-symbol

implementing setElement symbol on SetterObservable

setter/setter-test.js

@@ -2,6 +2,8 @@ var QUnit = require('steal-qunit');
 var SetterObservable = require('./setter');
 var SimpleObservable = require('../can-simple-observable');
 var canReflect = require('can-reflect');
+var Observation = require("can-observation");
+var canSymbol = require("can-symbol");
 
 QUnit.module('can-simple-observable/setter');
 
@@ -111,3 +113,18 @@ QUnit.test("getValueDependencies", function(assert) {
 		new Set([value])
 	);
 });
+
+QUnit.test("has setElement Symbol", function(assert) {
+	var setElementSymbol = canSymbol.for("can.setElement");
+	var setterObservable = new SetterObservable();
+	var obs = new Observation();
+	var el = {};
+	obs[setElementSymbol] = function(passedEl) {
+		assert.ok(true, "underlying observation's setElement Symbol is called");
+		assert.equal(passedEl, el, "observation's setElement is passed element");
+	};
+
+	setterObservable.observation = obs;
+
+	setterObservable[setElementSymbol](el);
+});

setter/setter.js

@@ -3,6 +3,9 @@ var canReflect = require("can-reflect");
 var Observation = require("can-observation");
 var SettableObservable = require("../settable/settable");
 var valueEventBindings = require("can-event-queue/value/value");
+var canSymbol = require("can-symbol");
+
+var setElementSymbol = canSymbol.for("can.setElement");
 
 // SetterObservable's call a function when set. Their getter is backed up by an
 // observation.
@@ -40,7 +43,10 @@ SetterObservable.prototype.hasDependencies = function() {
 };
 canReflect.assignSymbols(SetterObservable.prototype, {
 	"can.setValue": SetterObservable.prototype.set,
-	"can.valueHasDependencies": SetterObservable.prototype.hasDependencies
+	"can.valueHasDependencies": SetterObservable.prototype.hasDependencies,
+	"can.setElement": function(el) {
+		this.observation[setElementSymbol](el);
+	}
 });
 
 module.exports = SetterObservable;