Custom shuttle component

Question

Oracle JDeveloper 11.1.1.2.0
Since the current adf component doesn't seem to allow me to show two columns, i'm trying to implement my own shuttle component.
I was able to accomplish this by creating two lists<VOrows> (trailing & leading) and using them as table binding and simple array logic in removing one row and adding to the other list...
Now i'd like to use view objects.
Let me just call the leading table (selected items) as right table and trailing table (available items) as left table.
I'm using an entity based view object for the right table since i'll be deleting or inserting data over there.
For my left table, i'm using a read-only view object which basically says Select all Items that is not on Right table's DB object. Everything seems ok when i placed the shuttle logic in app module as long as i don't re-execute query on the left table because if i re-execute query, it requeries from DB and unless i commit the right table's data, i'll end up getting newly inserted values on the right table showing up on the left all over again.
My shuttle logic is basically using both viewobjects iterator, insert to right table, then remove from left table... same logic on the reverse, delete from right table, insert to left.
This would have been feasible except that i have issues with sorting and filtering. If i allow users to filter or sort, it seems that the viewobject requeries, thus giving me the problem of having the same item in both tables.
In short, i'm trying to look for a solution where i can keep the left table from requerying or if i do choose to use an entity based VO for the left table so that i can use its cache, if i can find a way to commit right table without commiting left table.
Any hints or guides to what direction i should try or study is highly appreciated.
Edited by: Mar Vince Reyes on Jan 30, 2010 11:30 AM
Edited by: Mar Vince Reyes on Jan 30, 2010 11:32 AM

Answer 1

Hi Mar
For the shuttle VOs let us assume Code and Description attributes:
AvailableVo - Read-only VO containing all Available Codes
SelectedEv - Updateable VO containing the Selected Codes
We can override executeQueryForCollection on AvailableVo and set a WHERE clause that excludes the rows in SelectedEv.
Here is a sample implementation:
<li>In SelectedEvImpl add method getSelectedCodes() that returns a string of all Codes in the SelectedEv View Object.
    public String getSelectedCodes() {
        String quote = "'";
        String separator = ",";
        String selectedCodes = null;
        SelectedEvRowImpl row = null;
        //Create a secondary RowSetIterator to loop through this view object
        RowSetIterator rsi = this.createRowSetIterator(null);
     //Loop through the iterator and generate the string with Codes
        while(rsi.hasNext()){
            row = (SelectedEvRowImpl)rsi.next();
            String code = quote+row.getCode()+quote+separator;
            if (selectedCodes == null)
                selectedCodes = code;
            else
                selectedCodes = selectedCodes.concat(code);
        //Close secondary row set iterator
        rsi.closeRowSetIterator();
        //Remove the extra comma at the end of the string
        if (selectedCodes!=null)
          selectedCodes = selectedCodes.substring(0, selectedCodes.length()-1);
        return selectedCodes;
    }<li> In AvailableVoImpl we override executeQueryForCollection and set WHERE clause to exclude the rows in SelectedEv.
    protected void executeQueryForCollection(Object object, Object[] object2,
                                             int i) {
        String selectedCodes = ((AppModuleImpl) getApplicationModule()).getSelectedEv().getSelectedCodes();
        if (selectedCodes != null)
          setWhereClause("code not in ("+selectedCodes+")");
        super.executeQueryForCollection(object, object2, i);
    }<li> On your Page Binding under Executables section verify that SelectedEvIteraor is above the AvailableVoIterator.
<li> Partial trigger AvailableVo to refresh it as you shuttle Codes from AvailableVo to SelectedEv.
Mitesh
Edited by: Mitesh Gajjar on Jan 31, 2010 3:24 PM
Added rsi.closeRowSetIterator();