[Javascript] (no subject)

[Håkan Magnusson]

1. I'm not 100% sure on what you mean, but yes, the loMainItem can be 
referenced/accessed by all functions (in the same execution scope) if
you define it globally. Like so:

var loMainItem;
loMainItem = 'Hello World'

function Item0100( param1, param2, param3 ) {
	alert(loMainItem);
}

Item0100(1,2,3);  // Will alert 'Hello World'

JavaScript do support prototyping and inheritance, meaning you can 
create the loMainItem and let Itom0100 inherit from that object. This 
has to be done in a slight different way than what you might be used to. 
Have a look at this page:

http://www.crockford.com/javascript/inheritance.html

2. There is no built in reference to an objects "parent"/owner, but you 
can quite easily build that kind of relation while constructing your 
data set. I think the above link will throw you a good way in the right 
direction.

Regards,
H


Mike Dougherty wrote:
> Question 1 of 2:
> 
> I'm developing a stateful interface (with Javascript and DHTML) to 
> customize an object.  Suppose I have the following:
> 
> loMainItem.Item0200[1].Item0250[1].Item0100[1] = new Item0100( 
> *paramlist* )
> 
> where:
> function Item0100( param1,param2,param3 ) {
>   if (param1 == 0) {
>     this.prop1 = loMainItem.prop1  /* inherit from loMainItem */
>     *** more code removed for brevity ***
>     } /* if(param1 == 0) */
>     else {
>       this.prop1 = param1 /* value from parameter */
>       *** more code removed for brevity***
>       } /* ELSE: if(param1 == 0) */
>   } /* Item0100(..) */
> 
> 
> Can the loMainItem object be referenced if it is defined in a global 
> scope?  (it does not appear to work)  This would be a lazy solution to a 
> server-side data aquisition problem that would probably be better served 
> 'the right way' - so I'm mostly interested in an explaination of any 
> scoping issues around the object constructor function.
> 
> Question 2:
>   Given the object(s) above, can I implicitly reference an object's 
> parent with "this.parent"? Most of the online help i've seen refers to 
> the parent of built-in objects, so I don't know how to use it on custom 
> objects.
> ex:
>   loCurrentItem0100 = loMainItem.Item0200[1].Item0250[1].Item0100[1]
>   alert( "Parent object: " + loCurrentItem0100.parent.Item0250Id )
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