String to Object convertion

[felic]

Hi all,

i have got:

(syntax only to visualize)

elem = elem // object reference of elem
a = 'parentNode.parentNode'; //manual build string
 

What i want to achieve:

'elem.a.getAttribute('xxx');'

where 'a' should be recognized as a object pointer - and not as the string, it is original defined.

is there any way of doing this (hopefully without the use of 'eval') ?

Thanks in advance for any hints!
greets
felic

[gits]

hi ...

we may use something like the following example:

var inp = document.getElementsByTagName('input')[0];
var str = 'parentNode.parentNode';
 
function get_node(base_node, str) {
    var nav  = str.split('.');
    var node = base_node;
 
    for (var i in nav) {
        node = node[nav[i]];
    }
 
    return node;
}
 
alert(get_node(inp, str).tagName);
 

just tested with the google-homepage in firebug-console. a property of an object might be referenced by .property_name or with the array-reference-notation ['property_name'] and we could make use of this here again :)

kind regards

[rnd me]

there is no cross borswer way to do (exactly) what you want.

this works in firefox to give every node an 'a' property, an object ref to the grandparent node

Object.prototype.__defineGetter__("a", function () {
if(this.parentNode && this.parentNode.parentNode){
return this.parentNode.parentNode;}});

this would let you code like you want (i think)

[rnd me]

Hi all,

i have got:

(syntax only to visualize)

elem = elem // object reference of elem
a = 'parentNode.parentNode'; //manual build string
 

What i want to achieve:

'elem.a.getAttribute('xxx');'

where 'a' should be recognized as a object pointer - and not as the string, it is original defined.

is there any way of doing this (hopefully without the use of 'eval') ?

Thanks in advance for any hints!
greets
felic

actually, i think what you might be asking is how to use strings to refer to objects:

change it slightly to

a = 'parentNode.parentNode'; //manual build string
 
elem[a].getAttribute('xxx');

you can use eval or a function to delay the evaluation of the string, adding additional quotes where (or perhaps when) you want the properties 'stringified'

[gits]

hi rnd_me ...

could you tell me what would be wrong with the code i posted in post #2? as far as i'm aware that code does what the OP wanted without eval and/or a fixed number of properties or might be i misunderstood the question?

kind regards