Iterate through JSON property list

[RMWChaos]

Any JSON experts out there? I'd like to know if it is possible, and if so how, to iterate through a JSON property list so that each iteration selects the next value for each object. Here is an example list:

function myFunction()
{
    createDOM({
    'id'      :   ["formname", "inputname", "submitbutton"],
    'dom'     :   ["form", "input", "input"],
    'parent'  :   "content",
    'form'    :   [null, "formname", "formname"],
    'action'  :   [URI, null, null],
    'method'  :   ["post", null, null],
    'type'    :   [null, null, "submit"],
    'size'    :   [null, 6, null],
    'value'   :   [null, null, "Submit"],
    )};
};
 

Now what I want to do is iterate through this list 3 times, in each case selecting the next value for each object. So through each iteration, it will go through all the objects (id, dom, parent, etc.). On the first run it will select the first set of values for each object (formname, form, content, null, URI, etc.). On the second run, it will select the second set (inputname, input, content, formlogin, etc.) and so on. In the case of the 'parent' object, it will select 'content' on each run.

I know one way to do this, but it involves creating an array for each object's value list, like so:

function myFunction()
{
var A = new Array ("formname", "inputname", "submitbutton");
var B = new Array ("form", "input", "input");
var C = new Array(null, "formname", "formname");
var x = 0;
var D = A.length + x;
var E = B.length + x;
var F = C.length + x;
 
for (x <= 3; x >= 0; x++)
    {
    createDOM({
    'id'      :   D,
    'dom'     :   E,
    'parent'  :   F,
    )};
};
 

That would result in a long list of arrays and "array.leng th + x" vars. So I am hoping there is an easier way by working with the first example.

Thanks!

[gits]

I do have one other question, however. You have the exceptions in a JSON list, so I copied what you did, but is that necessary? Why not just:

var exceptions = new Array ("onclick", "onmouseover", "onmouseout");
 

There is no data to hold here; so I guess I am missing the point of a JSON property list.

Thanks!

it's not really called a json-list ... its a simple javascript object. have a look at the following simple usage:

if (index in exceptions) {
   // some code
}
 

that wouldn't be possible with an array :) where you would always have to loop through when checking a value. so the current code simply avoids that. and one more note ... simply to mention :) ...

// create an array-instance
var arr = new Array();
 
// equivalent to this :: but js needn't to evaluate
// the brackets
var arr = new Array;
 
// equivalent to this :: more less to evaluate :) through
// the use of literals
var arr = [];
 

kind regards

[RMWChaos]

Hey gits,

Yeah, I tried it out, and it didn't work. =\

Sometimes, it's the only way to learn.

Thanks!

[RMWChaos]

I asked why this:

/**
* @private
*/ 
 

You replied:
that's for marking, that you shouldn't use that method seperatly ... only set_node_attr() ; should be used in the code. the reason for that is, that you later on simply may change the functions without changing the code in different places, and so centralizes the attrib/property setting in one place.

I'm not quite sure what you mean. Maybe it would be easier if I learned Deutsch. =D I think you mean by using that code snippet, it forces all functions that come after it to only be used in conjunction with the function before it, or is it just a reminder to the programmer?

As for util-method...Ok, ok, ok, you win! I will make these changes:

//in changeAttrib
function changeAttrib(id, attr, value))
     {
     set_node_attrib(id, attr, value, false);
     };
 
// in createDOM()
for (index in attrib)
     {
     set_node_attrib(attrib.id, index, attrib[index], true);
     };
 
// in set_node_attrib
function set_node_attr(id, attr, value, state)
     {
     var node = docroot.getElementById(id);
     var exceptions = 
          {
          'onclick'     :   1,
          'onmouseover'    :   1,
          'onmouseout'    :   1
          };
     if (attr in exceptions)
          {
          set_node_exceptions();
          }
     else if (state)
        {
        node.setAttribute(attr, value);
        }
     else
          {
          node.removeAttribute(attr);
          };
     };
 
/**
* @private
*/
 
function set_node_exceptions(node, attr, value)
     {
     node[attr] = value;
     };
 

[gits]

it's a reminder as you said ... and the programmer should pay attention to it :) it's always a good idea to handle things that mix up different things like our attribute/property example in one place ... respectively with one single method-call ... so that everytime you have to build in more exeptions you have only one point where you have to maintain the code ;) ...

kind regards

[RMWChaos]

it's always a good idea to handle things that mix up different things like our attribute/property example in one place ... respectively with one single method-call ... so that every time you have to build in more exceptions you have only one point where you have to maintain the code

I understand exactly what you are saying, but I have a problem in using this code. The util-method assumes that the node-id already exists, but in the case of my createDOM script, it does not. The attribs are being set immediately before the node is actually created, so that the node is created with the attribs. Hm, let me see if I can create the node, then set the attribs. That might work...testing. ..

Nope, didn't work. Again, the problem is that no attribs have been set, including the node id, so that document.getEle mentById(id) has nothing to find. If I am going to use your util-method, I really need to give this some thought.

[gits]

simply change it to pass the node itself to it instead of the id :)

kind regards