Problem when iterating a context-node

[Former Member]

Hi Experts,

I have the following context-structure in my WebDynpro-View (generated by WebService-Wizard):

+ Context
-----+ filterApps (0..n)
---------+ ResponseFilterApps (0..1)
---------------+ ResultFilterApps (0..n)
--------------------+ hwCompFilterApps (0..1)
--------------------+ swCompFilterApps (0..1)
-------------------------+ anwendungstitel (String)
-------------------------+ bezeichnung (String)

The cardinalities respectively datatypes are given in brackets (btw: I do not have any idea why the cardinality of "filterApps" is (0..n) - in other applications I have developped this is (0..1) - but does not seem to be a problem because the node's size() is 1).

After calling my WebService I receive 85 results, so the size() of node "ResultFilterApps" is as expected 85.

But traversing the node makes problems (see below). Here is my code:

IResultFilterAppsNode source = wdContext.nodeResultFilterApps();
System.err.println("size = " + source.size());
Iterator iter = source.iterateChildNodes();
int ix = 0;
while (iter.hasNext()) {
   ISwCompFilterAppsNode myNode = (ISwCompFilterAppsNode)iter.next();
   ix++;
   System.err.println("accessing element " + ix);
}

This code results in following output:

size = 85
accessing element 1

Why does the iterator only contain 1 element instead of 85 elements?

Surprisingly I can call

myNode.getCurrentElement().getAttributeAsText("anwendungstitel");

This gives me the content of value attribute "anwendungstitel" of the first result delivered by my WebService.

Calling

myNode.getElementAt(0)

is ok, but calling

myNode.getElementAt(1)

leads to an IndexOutOfBoundsException.

What goes wrong? I am working with 2004s.

Thanks for every hint,

Christoph

[Former Member · Accepted solution]

(I assume that node swCompFilterApps is non-singleton, is that the case?)

IResultFilterAppsNode results = wdContext.nodeResultFilterApps();
for (int i = 0; i < results.size(); ++i)
{
  IResultFilterAppsElement e = results.getResultFilterAppsElementAt(i);
  IswCompFilterApps swNode = e.nodeswCompFilterApps();
  if (swNode.size() > 0)
  {
    IswCompFilterAppsElement sw = swNode.getswCompFilterAppsElementAt(0); 
    String titel = sw.getAnwendungstitel();
    String bez = sw.getBezeichnung(); 
  } 
}

Armin

[Former Member · Accepted solution]

Hi Armin,

thanks for trying to help. But it diesn't work.

IResultFilterAppsElement does not provide a method named "nodeSwCompFilterApps()". It only provides a method named "node()".

Method "getSwCompFilterAppsElementAt()" is undefined for class ISwCompFilterAppsNode, so I have to use

ISwCompFilterAppsElement sw = (ISwCompFilterAppsElement)swNode.getElementAt(0);

instead.

In summary I have to modify your code to the following:

IResultFilterAppsNode results = wdContext.nodeResultFilterApps();
		for (int i = 0; i < results.size(); ++i)
		{
		  IResultFilterAppsElement e = results.getResultFilterAppsElementAt(i);
		  ISwCompFilterAppsNode swNode = (ISwCompFilterAppsNode)e.node();
		  if (swNode.size() > 0)
		  {
			//ISwCompFilterAppsElement sw = swNode.getswCompFilterAppsElementAt(0); 
			ISwCompFilterAppsElement sw = (ISwCompFilterAppsElement)swNode.getElementAt(0);
			String titel = sw.getAnwendungstitel();
			String bez = sw.getBezeichnung(); 
		  } 
		}

This leads to a ClassCastException performinng the statement

ISwCompFilterAppsNode swNode = (ISwCompFilterAppsNode)e.node();

Regards,

Christoph

[Former Member · Accepted solution]

Is node swCompFilterApps non-singleton? (That was my assumption.)

Is "typedAccessRequired" set to true?

Your modification to my code is wrong. The node() method gives you the <b>containing </b>node for a node element, the node<Subnode>() gives you the (non-singleton) <b>subnode </b>for a node element.

Armin

[monalisa_biswal · Accepted solution]

Set singleton property of subnodes to false.

After that you will be able to access subnodes from the parent element.

[Former Member · Accepted solution]

Hi Monalisa,

how could I do this? The node was originally created by the wizard that imports a WebService into my WD-model. The wizard defined the cardinality in the model and I cannotr change this. Mapping the node from model to controller effects that the generated context-node has the same cardinality. Cardinality of the context-node cannot be changed because it is mapped from the model.

Regards,

Christoph

[Former Member]

Ok, I've got a suitable solution for me. I still do not understand why iterateChildNodes does not work as I think it should work Obviously there is something I do not understand. But here's my solution for iterating child nodes (even if I know that I am moving in model with this solution and not in the view's context):

IResultFilterAppsElement elem;
int resCnt;

IResultFilterAppsNode source = wdContext.nodeResultFilterApps();
resCnt = source.size();
System.err.println("size = " + source.size());
			
for (int ix=0; ix<resCnt; ix++) {
	elem = source.getResultFilterAppsElementAt(ix);
	System.err.println("Titel " + ix + ": " + elem.modelObject().getSwComp().getAnwendungstitel());
}

[Former Member]

Christoph,

The same should work as well if ResultFilterApps and swComp is non-singleton nodes and swComp has initializeLeadSelection=true:

System.err.println("Titel " + ix + ": " + elem.currentSwCompElement().getAnwendungstitel());

VS

[Former Member]

Christoph,

Either you are posting incomplete/modified code or your code is totaly broken.

You are iterating over node ResultFilterApps but getting elements swCompFilterApps from iterator. In reality your app should print size (85) and then fail with class cast exception.

Additional hint: make sure that swCompFilterApps is not a singleton.

Valery Silaev

SaM Solutions

http://www.sam-solutions.net

[Former Member]

Hi Valery,

in fact it's right: I get the output "size = 85". But I do not get any ClassCastException.

Concerning your hint to the cardinality of swCompFilterApps: I think that this is in fact the problem. But as I already answered to Monalisa:

"How could I set the cardinality to "0..n"? The node was originally created by the wizard that imports a WebService into my WD-model. The wizard defined the cardinality in the model and I cannotr change this. Mapping the node from model to controller effects that the generated context-node has the same cardinality. Cardinality of the context-node cannot be changed because it is mapped from the model."

Any more idea?

Regards,

Christoph

[Former Member]

Christoph,

You always can change cardinality of root model node to 0..1. Also you may change singleton/non-singleton property of node in question. Just edit context of component controller (rather then view context).

Valery Silaev

SaM Solutions

http://www.sam-solutions.net

[Former Member]

Hi,

Try this, it will help u

int size=wdcontext.nodeResultFileterApps().size();

int counter=0;

for(int i=0;i<size;i++)

{

IResultFilterAppsNode source = wdContext.nodeResultFilterApps().getResultFilterAppsElementAt(i);

System.err.println("size = " + source.size());

Iterator iter = source.iterateChildNodes();

int ix = 0;

while (iter.hasNext()) {

ISwCompFilterAppsNode myNode = (ISwCompFilterAppsNode)iter.next();

ix++;

System.err.println("accessing element " + ix);

}

System.err.println("counter: " + counter);

counter++;

}

[Former Member]

Hi Siva,

sorry, this can't work. getResultFilterAppsElementAt() delivers IResultFilterAppsElement, not IResultFilterAppsNode as in your suggested code. And IResultFilterAppsElement does not know methods "size()" and "iterateChildNodes()".

Thanks for trying to help,

Christoph

[Former Member]

Hi Christiph,

Try using,

IResultFilterAppsNode source = wdContext.nodeResultFilterApps();

System.err.println("size = " + source.size());

For(int i =0 ; i<source.size() ; i++)

{

IResultFilterAppsElement ele = source.getResultFilterElementAt(i);

wdComponentAPI.getMessageManager().reportSuccess("Accessing Element: " + i);

}

Hope this helps.

Regards,

Mausam

[Former Member]

Hi Mausam,

thank you for help. In fact I receive 85 outputs as expected. But how can I access the 85 elements? I tried the following:

System.err.println("titel " + i + " : " + ele.getAttributeAsText("anwendungstitel"));

Result is a NullPointerException in getAttributeAsText()

System.err.println("titel " + i + " : " + ele.getAttributePointer("anwendungstitel"));

Result is an IllegalArgumentException in getAttributePointer (No such attribute anwendungstitel)

System.err.println("titel " + i + " : " + ele.getAttributePointer("swCompFilterApps"));

Result is an IllegalArgumentException in getAttributePointer (No such attribute swCompFilterApps)

Any more ideas?

Regards,

Christoph

[Former Member]

Hi Christiph,

Try using,

IResultFilterAppsNode source = wdContext.nodeResultFilterApps();

System.err.println("size = " + source.size());

For(int i =0 ; i<source.size() ; i++)

{

IResultFilterAppsElement ele = source.getResultFilterElementAt(i);

wdComponentAPI.getMessageManager().reportSuccess("Accessing Element: " + i);

}

Here, "ele" in the For loop is your required element at "i".

You can go through all the methods of "ele", like for getting your "titel", you can use "ele.getTitel()" method. Same for the other attributes.

Hope this helps.

Regards,

Mausam>

[Former Member]

Hi Mausam,

sorry for my late answer. "ele" does not provide any methods like "getTitle()". It only provides methods like "getAttributeValue()", "getAttributeAsText()", "getAttributePointer()". The problem seems to be that under my node "ResultFilterApps" there are two other nodes ("hwCompFilterApps" and "swCompFilterApps"). The real attributes are located under these nodes. How can I access the nodes "hwCompFilterApps" and "swCompFilterApps" or the attributes under these nodes?

Regards,

Christoph

[monalisa_biswal]

IterateChildNode does not iterate through elements , it helps in iterating child nodes of the node.To access elements of the node

int size =wdContext.node<NodeName>().size();

for(int i=0;i<size;i++)

{

msgMgr.reportSuccess(

wdContext.node<NodeName>().getElementAt(i).getAttributeAsText("<attributeName>");

}

[Former Member]

Hi Monalisa,

thanks for trying to help. But it doesn't work. It results in a NullPointerException in getAttributeAsText(). I tried with <attributeName> "anwendungstitel" and "swCompFilterApps".

Do you have any more ideas?

Regards,

Christoph