DO NOT REPLY [Bug 26671] New: - indexed properties can be only used with forms in the session scope

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http://nagoya.apache.org/bugzilla/show_bug.cgi?id=26671

indexed properties can be only used with forms in the session scope

           Summary: indexed properties can be only used with forms in the
                    session scope
           Product: Struts
           Version: 1.1 Final
          Platform: Other
        OS/Version: Other
            Status: NEW
          Severity: Normal
          Priority: Other
         Component: Controller
        AssignedTo: struts-dev@jakarta.apache.org
        ReportedBy: olgt@yahoo.com


If an action form has a indexed property defined as ArrayList elements = null 
and consists of instances of MyClass (that has some properties on its own) then 
in order for struts to fill the html property elements[x].bb with the value 
from the request, attribute aa should not be null. But elements will be null if 
1.	the form is in the request scope 
2.	and not initialized in the form. 
While initializing the form nested property can be done in some cases it can 
not be done with collections because the number of elements is unknown in 
advance. Example:

PrepareListAction – creates a form MyForm instance and initializes the form’s 
attribute ArrayList aa with an ArrayList of objects MyClass. It then forwards 
the control to the ShowList.jsp which displays the elements using indexed 
property of the html:text tags which will result in html elements with names 
like elements[x].bb. The ShowList.jsp then submits the data to the 
SaveListAction.

If the MyForm is defined in the session scope, then the collection initialized 
in the PrepareListAction remains in the scope and everything works fine. But if 
the form bean defined in the request scope, then the NullPointerException is 
thrown when request is parsed and an attempt is made by struts to assign the 
value to the element of the collection instance variable. Collection can not be 
just initialized in the form because the number of the elements is unknown. 
Note. ArrayList aa = new ArrayList() does not make any difference as it causes 
java array indexed exception when struts try to assign the value to the element 
with a given index to an empty collection.

How difficult would it be to initialize the indexed properties with the right 
number of elements that is known from the request ?

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