Null Pointer exception in Dropdownbyindex

[Former Member]

Dear Forum,

I am using a dropdownbyindex to populate values from R/3.

My requiremnt is initially the dropdown will show emply field. The user will select a value and submit. But if the user does not select and submits, the UI is throwing a Nullpointer exception.

I can avoid the null value in dropdown by setting the selection as 1...1 ; but this is not serving the purpose of blank value initially.

Please help me asap.

Thanks and regards,

Mickey.

[Former Member · Accepted solution]

Hi,

This is because you have binded the DDB Index to a context attribute and you are accessing it in your code.

So please use this statement in your code

if(wdContext.currentContextElemem.getAttr1()!=null){

// your code

}

else {

wdComponentAPI.getMessageManager().reportException("Plesae select a value in the drop down");

}

Hope this helps,

Jithin

Edited by: jithin james on Mar 23, 2009 9:17 AM

[Former Member · Accepted solution]

Jithin,

Thanks for your reply. But before this code is executed, Null pointer exception is thrown.Also i have used model node to map data.

Do you need any more inputs from my side?

With Regards,

Mickey.

91-9830122905.

[Former Member · Accepted solution]

Hi,

Can u please post the code portion where you are getting this error.

jithin

Edited by: jithin james on Mar 23, 2009 9:38 AM

[Former Member]

Hi,

You can add empty row in your r/3 table. it is possible i have done it previously. For R/3 nodes the cardinality is 0..n initially. You need to do instantisate the node in component controller. please change the model node cardinality by 0..n & instansitiate the node in your component controller. your problem will be solved.

Best Regards

Ravi

[Former Member]

Hello Everybody,

Thanks a lot for your suggestions. I solved the issue.

I made the UI property "setInitialized" to true which allowed the blank entry (provided by framework) to get displayed. Then I kept a check on null pointer exception where in it is mandatory for the user to enter a value to dropdown before submitting the form.

Thanks again,

Best regards,

Mickey.

[Former Member]

Hi Mickey,

You can achive it by setting the selection as 1...1 and then before taking the data from R3 and adding it to dropdown what you can do is.

Create a String string blank ="";

and now assign this value to the node element. and now assign the vlaue from R3 to this node.

This will solve your problem.

Hope this will help

Regards

Narendra

[Former Member]

Hi ..

you have to create VALUE NODE in component Context...and mapping Into VIEW context through open navigator model..

inputdrop----is the attribute name

SearchCriteria--Value node

In component implemation you have to put some code..in appropriaate method...

IWDAttributeInfo attrinfo=wdContext.nodeSearchCriteria().getNodeInfo().getAttribute("inputdrop");

ISimpleTypeModifiable msType=attrinfo.getModifiableSimpleType();

IModifiableSimpleValueSet valueSet3=msType.getSVServices().getModifiableSimpleValueSet();

valueSet3.put("Plese choose");

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

{

valueSet3.put(wdContext.node<model>().get<model>ElementAt(i).getAttributeAsText("your value in model as key",wdContext.node<model>().get<model>ElementAt(i).getAttributeAsText("your value in model as description")

}

wdContext.currentSearchCriteriaElement().setInputdrop("Please choose");

thanks..

sudhira

Edited by: sudhir kumar on Mar 23, 2009 10:44 AM

[Former Member]

Hi,

Which line you exactly get the Null Pointer?

Regards,

Daniel

[Former Member]

Hi,

Please post the trace of the error

Check in your code for a call to the metthod "currentContextElement" of the respective node and make sure that you check for the null before calling this method.

Ex:

if(!wdContext.nodeEmployees().isEmpty()) // Employee is the node Name
		  id = wdContext.currentEmployeesElement().getEmpID()

Regards

Ayyapparaj

[Former Member]

Hi Mickey,

Please check the value of the dropdown field & if it is not null then call the code in onAction method of Submit button.

Kind Regards,

Nitin

PS: I feel your application logic should handle it in a more efficient manner than to check for null values.

You may enable the submit button only if the dropdown is filled (associate a label & mark it as mandatory), and in onSelect method of dropdown, make the submit button enabled.

Edited by: Nitin Jain on Mar 23, 2009 9:19 AM

[former_member185086]

Hi

Just it require a null check then only retrieve the value from dropdown

if(Wdcontext.currentContextElemem.getValue !=null)
{

//code 

}

Other solution is populate the value form R/3 in Dropdown (only if it is less than 50), else use EVS for better functionality(Default filter is there for large body data say 100-150),

Best Regards

Satish Kumar