Question

I have a javascript object, and I want to recursively search it to find any properties that contain a specific value.

The javascript I’m working with has been minified, and is not so easy to trace through.

Background

I’m using the Bing Maps AJAX SDK. It has the ability to add additional tile layers. Each tilelayer has a tilesource object, which specifies the URI format for the tile URL.

I’ve ran into a problem where the tilesource URI is created once, and cached. Thus I can’t dynamically change the parameters of the URL (for example, to change the colors of the tile overlay based on the time of day) for each request.

Note that this behavior is different that Google’s Map API, and the Bing Maps api for WP7, which both allow you to dynamically create the URL for each tile request.

The cached URI is looked up, and two specific parameters are replaced, then the URI is used to fetch the tile.

Since this is javascript, I’d like to find the cached URI, and replace it with a function, that instead dynamically builds the URI, and returns it.

I don’t need to do this each runtime, just want and idea of where the property is being cached, so I can write code to hax0r it.

Original Question

If I set the URI to some value like “floobieblaster”, when I set a breakpoint, can I search the javascript object recursively for “floobieblaster” and get the property that is storing that value?

Edit to add

The object I’m searching appears to have a circular reference, thus any recursive code will likely cause a stackoverflow.

Are there any editor/debugger tricks I could make use of?

Answer 1

Something simple like this should work:

var testObj = {
    test: 'testValue',
    test1: 'testValue1',
    test2: {
        test2a: 'testValue',
        test2b: 'testValue1'
    }
}

function searchObj (obj, query) {

    for (var key in obj) {
        var value = obj[key];

        if (typeof value === 'object') {
            searchObj(value, query);
        }

        if (value === query) {
            console.log('property=' + key + ' value=' + value);
        }

    }

}

If you execute searchObj(testObj, 'testValue'); it will log the following to the console:

property=test value=testValue
property=test2a value=testValue

Obviously, you can replace the console.log with whatever you want, or add a callback parameter to the searchObj function to make it more reusable.

EDIT: Added the query parameter which allows you to specify the value you want to search for when you call the function.