10.1.3: How are client ids for elements in an af:table determined?

Question

Hi all,
I have an af:table (let's say Departments) with some columns (let's say DeptName) is one of them, and (let's say) a 15-row range. Normally, modulo naming containers, the clientId of a particular DeptName field is of the form:
Departments:0_indexed_row_in_af_table:DeptName
So, for example, the DeptName field in the third row of the table will be
Departments:2:DeptName
The problem occurs when, due to, say, a data change and requery, a partially distinct set of rows appears in the table on refresh. Then, any old rows that reappear will keep their old clientIds, but new rows will get new numbers,starting with 15. So, if the refresh retains the first and third rows in the first and fourth positions, and retrieves new rows for the second and third position, the client IDs for the first four departments fields as they appear in the table will be:
Departments:0:DeptName
Departments:15:DeptName
Departments:16:DeptName
Departments:2:DeptName
If the data's completely new, the table will be rendered starting with Departments:15:DeptName.
My question: Is there any way to figure out, programmatically, what the client ID for a particular DeptName field will be, assuming that the table might have been refreshed with partially or completely new data an arbitrary number of times?
Thanks much for any help,
Avrom

Answer 1

Hi,
Try something like the following:
RichTable table = // Get the table component instance somehow;
int rowIndex = // Find the right row and get its INDEX in the ResultSet and/or data, not the row key
// Save row state
Object oldRowKey = table.getRowKey();
try
    table.setRowIndex(index);
    UIComponent field = table.getChildren().get(columnIndex).getChildren().get(0); // Get the field from column columnIndex
    field.getClientId(FacesContext.getCurrentInstance()); // Since setRowIndex was called, the id should be correct
finally
    // Restore state
    table.setRowKey(oldRowKey);
}The idea of rowKey vs. rowIndex is that rowKey is stable to ensure that a given row key is always the same row (very useful to avoid some strange issue with sorting), whereas row index change with the position of the row.
Regards,
~ Simon