Pass all rows from GridPanel that have certain value in a specific column

[rezoan]

I have a Ext GridPanel named sampleGrid, which has some column. one of them is named IsAssigned holding a bool value.

I have a ext button. when i click to it i want to pass all the row that has IsAssigned column value false.

i can pass all the grid rows, See below code sample,

<ext:Button ID="btnSave" runat="server" Text="Save"
                                Icon="Accept">
                                <DirectEvents>
                                    <Click OnEvent="btnSave_Click">
                                    <ExtraParams>
                                    <ext:Parameter Name="rows" Value="Ext.encode(#{sampleGrid}.getRowsValues())"
                                     Mode="Raw" ></ext:Parameter>
                                    </ExtraParams>
                                    </Click>
                                </DirectEvents>
                            </ext:Button>

Here Ext.encode(#{sampleGrid}.getRowsValues()) will pass all the rows. but i want to pass only rows that has IsAssigned column value false.

isAssigned collum code:

<ext:CheckColumn ColumnID="chkSelect" DataIndex="IsAssigned" MenuDisabled="true"
                                            Sortable="true" Width="30px" Editable="true">
                                        </ext:CheckColumn>

Any Help will be appreciated.

[Zdenek]

define somewhere following function

function findCustom(grid){
    var result = [];
    var store = grid.store;
    for(var i=0;i<store.getCount();i++){

        if(store.getAt(i).get('IsAssigned'))
              result.push(store.getAt(i).data)
    }
    return result

}

and modify parameter

 <ext:Parameter Name="rows" Value="Ext.encode(findCustom(#{sampleGrid}))"   Mode="Raw" ></ext:Parameter>

[rezoan]

Thanks Zdenek for the reply its helpful but returns only the true columns row. but i want the false column rows

By the way i have solved this using filterRecord,

<ext:Parameter Name="rows" Value="Ext.encode(#{sampleGrid}.getRowsValues(
                                    {
                                    filterRecord : function (record) {
                                    return (record.data.IsAssigned==false); }
                                    })
                                    )" Mode="Raw" ></ext:Parameter>

Again thanks for the reply. :)