window["object.something"] not working for objects javascript

Question

Hi I just can't figure this one out.

I need to use the window["evaluate string into js object"] because I am converting a web Application into a ChromeOS Chrome app and they do not let you use eval() to do their content security policy.

My problem is that for basic varibles it is fine, example:

var a = "foo";

var b = window["a"];

This will put "foo" into b no problem. But as soon as I have an object (both global or local) it doesn't work, so if 'a' was an object the code would like something like this:

a.test = "foo";

var b = window["a.test"];

That will not work.

Is there a reason for this? I can't seem to find much info on window[] in general so wondering if anyway has any insight or at least can point me in the right direction to look.

Thanks

You are trying to look into a property of a property of the window, you are interpreted as trying to fine the property (*as the string*) `"a.test"`. Are you allowed to do `window["a"].test`? I'm also don't see why `eval` would help here. — Spencer Wieczorek, Jul 15 '16 at 00:06
http://stackoverflow.com/questions/6393943/convert-javascript-string-in-dot-notation-into-an-object-reference — epascarello, Jul 15 '16 at 00:30

score 1 · Accepted Answer · answered Jul 15 '16 at 00:39

window[] doesn't work on namespaced functions, so if you try to evaluate window['a.test'] it would fail. A proper alternative is to use window['a']['test']. In case you're indefinite of number namespaced objects you're going to use, you can create a simple function that would split the string from . and create a window object for each part. Example :

var str = 'namespace.service.function';
var parts = str.split(".");
for (var i = 0, len = parts.length, obj = window; i < len; ++i) {
    obj = obj[parts[i]];
}
console.log(obj);

window["object.something"] not working for objects javascript

1 Answers1