grails - update parent and children items throws out of bounds exception

Question

I have two classes a parent class:

class parentItem{
     User        user

     Date    startTime
     Date   endTime
     ------

     Date        dateCreated
     Date        lastUpdated

     static hasMany = [ childItems: ChildItem ]

and a child Class

class ChildItem{


static belongsTo = [parent : ParentItem]    
---------
Date time
Date dateCreated
Date lastUpdated

In the gsp file that allows items to be edited I have a table with rows that look like this:

<table id="childDataTable" class="childData">
<g:each in="${ParentInstance?.childItems?.sort{it.id}}" var="childItem" status="i">
<tr class="childRow">
            <td>
         <g:hiddenField name="childItems[${i}].id" value="${childItem.id}"/</td>
         ------
        <td>
        <g:textField name="childItems[${i}].time" class="time" value="${childItem.time}"/>

            </td>               
            <td><a href="#" class="removeButton">&#10006;</a></td>  
        </tr>
    </g:each>
        </table>

So my question stems from the fact that in the controller I've tried to update this parentItem where some of the childItem data may also have been changed. I need both the parentItem and the collection of childItems to update and save.

In the controller I've tried this

def parentInstance = ParentItem.get(params.id)
bindData(parentInstance, params)

and I've tried

def parentInstance = ParentItem.get(params.id
parentInstance.properties = params

Both ways I get a Out of Bounds Exception

In a case where I have two child Items the message looks like this:

Index: 1, Size: 1. Stacktrace follows:
java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
at java.util.ArrayList.rangeCheck(ArrayList.java:604)
at java.util.ArrayList.get(ArrayList.java:382)
at com.sexingtechnologies.laboratory.ParentItemController$_closure7$$EOChoLzu.doCall(ParentItemController.groovy:158)
at grails.plugin.multitenant.core.servlet.CurrentTenantServletFilter.doFilter(CurrentTenantServletFilter.java:53)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:722)

I'm not sure where the error exists or how to solve it.

I've tried to extract the childItems from params map but have not been able to do so successfully.

Any help you be appreciated

Answer 1

Maybe you could initialize the childItems before the data binding like so:

def parentInstance = ParentItem.get(params.id)
parentInstance.childItems = [].withDefault { new ChildItem() }
bindData(parentInstance, params)

See here for more about the withDefault method.