Javascript – pass a JavaScript variable to another browser window

browserjavascript

I have a page which spawns a popup browser window. I have a JavaScript variable in the parent browser window and I would like to pass it to the popped-up browser window.

Is there a way to do this? I know this can be done across frames in the same browser window but I'm not sure if it can be done across browser windows.

Best Answer

Putting code to the matter, you can do this from the parent window:

var thisIsAnObject = {foo:'bar'};
var w = window.open("http://example.com");
w.myVariable = thisIsAnObject;

or this from the new window:

var myVariable = window.opener.thisIsAnObject;

I prefer the latter, because you will probably need to wait for the new page to load anyway, so that you can access its elements, or whatever you want.

Do:

var isTrueSet = (myValue === 'true');

using the identity operator (===), which doesn't make any implicit type conversions when the compared variables have different types.

Don't:

You should probably be cautious about using these two methods for your specific needs:

var myBool = Boolean("false");  // == true

var myBool = !!"false";  // == true

Any string which isn't the empty string will evaluate to true by using them. Although they're the cleanest methods I can think of concerning to boolean conversion, I think they're not what you're looking for.

Javascript – How to use a variable in a regular expression

Instead of using the /regex\d/g syntax, you can construct a new RegExp object:

var replace = "regex\\d";
var re = new RegExp(replace,"g");

You can dynamically create regex objects this way. Then you will do:

"mystring1".replace(re, "newstring");

Best Answer

Related Solutions

Javascript – How to convert a string to boolean in JavaScript

Do:

Don't:

Javascript – How to use a variable in a regular expression

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