Passing / Referencing Objects

echovue · September 27th, 2007, 12:01 PM

This could be a tricky one, but I am sure it can be done - Just not sure how.

I have a global object which I declare at the start of my script.

In one of my functions, I then want to set that object based on a function which I am including from a library.

The library function initiates an AJAX call, and then attempts to copy the returning xmlObject to the Global Object. That all works fine, except the Global object doesn't hold the xmlObject once it leaves the function. I suspect that a local object is being created when I pass it in.

I think the easy question is this... Is there a way to reference the Global variable without just calling it's name? Something like window.Objects("GlobalObject")

If not, here is what I am trying to accomplish

globalObject = new Object();

assignObject(globalObject, 1, 2);

//Heres the library function (needs to be very generic)
assignObject(globalObjectName, param1, param2)
{
'Logic here to retrieve an xmlObject
globalObjectName = xmlObject;
}

I then want to work with the assignObject to retrieve the XML.

Any ideas? Clarification needed?

Thanks

Mike

Mike
EchoVue.com

joefawcett · September 27th, 2007, 01:10 PM

You'll have to show some simplified code. If you do this:

Code:

var o;

function doSomething()
{
  o = {name: "Joe"};
}

doSomething();
alert(o.name);

Then the o object declared at the beginning will have a property "name" with the value "Joe". If you use var inside the function then you are creating a different local variable.

Addition:
Sorry, didn't read your code carefully enough. JavaScript does not support passing by reference, you have two choices. Either just refer to the global object in the function or you assign the properties from one object to the other:

Code:

var o = {name: "Joe"};

function changeObjectName(obj, name)
{
  obj.name = name;
}

function changeObjectName2(name)
{
  o.name = name;
}

alert(o.name);
changeObjectName(o, "Joseph");
alert(o.name);
changeObjectName2("Joe Fawcett");
alert(o.name);

--

Joe (Microsoft MVP - XML)

echovue · September 28th, 2007, 09:28 AM

Thanks Joe,

That was the sad realization I came to. Found another way to pass the data, since the boss didn't want global variables floating around either! I was using a Javascript array, but since all I need is a list of text/value pairs, I wnet with a hidden select box instead. Works just as well, and actually makes debugging a fair bit easier.

Thanks again,

Mike

Mike
EchoVue.com