Is property assessor good or evil? C# thinks good and Java as contrast. What about JavaScript? Maybe yes, Maybe no...
Mozilla SpiderMonkey introduce variety of solutions for getter and setter. Here is the sample:
<html>
<head>
<script type="text/ecmascript">
function trace(msg) {
document.getElementById('console').innerHTML += msg + '<br />';
}
</script>
</head>
<body>
<div id="console" class="debug"></div>
<script type="text/ecmascript" src="test-js-getset.js">
</script>
</body>
</html>test-js-getset.js
=================function test1() { var obj = { prop getter: function () { return 'prop1'; } }; trace(obj.prop); obj.prop getter = function () { return 'prop2'; } trace(obj.prop); obj.prop getter = getter function () { return 'prop3'; } trace(obj.prop); } function test2() { function MyObj() { this.__defineGetter__('prop', function () { return 'prop1'; }); } var obj = new MyObj(); trace(obj.prop); obj.__defineGetter__('prop', function () { return 'prop2'; }); trace(obj.prop); } function test3() { var obj = { foo: null, get prop() { return 'prop1'; }, set prop(v) { trace(v); }, bar: null, }; trace(obj.prop); obj.prop = 'hello'; } test1(); test2(); test3();
Unfortunately, M$ IE supports no one of above. And even codes of test1() and test3() will cause syntax error. Only test2() can be interpreted by IE, u can catch the exception for the absence of __defineGetter__. But nothing else can u do, because I found no solution of emulating __defineGetter__ in IE, though there are some tricks to make a object with properties via wrap vbscript or introduce htc.
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