Find index number of selected item in Tlist

[newbill1]

I'm trying to delete an item from a Tlist when a user clicks on it. Is there a way to find out what the list index is for the currectly selected item in the list. I want to use DELETE_LIST_ELEMENT but need to know the index #.

Thx,

Bill

 

[lewisp]

If the elements in your tlist item are not ordered alphabetically or numerically, you will need to start at 1 and loop round every element in the list until you find the one you want. Note that p_item is the name of the list item in 'block.name' format, and p_value is the element label (or value) you are looking for.

[tt]FUNCTION f_get_index (p_item IN VARCHAR2,
p_value IN VARCHAR2)
RETURN INTEGER IS
l_index INTEGER;
BEGIN
FOR i IN 1..To_Number(Get_List_Element_Count(p_item))
LOOP
IF Get_List_Element_Label(p_item,i) = p_value
THEN
Return i;
END IF;
END LOOP;
--
Return 0;
END;[/tt]

However, if your items are ordered, you can use a much faster binary search like this

[tt]FUNCTION F_Get_Index (p_item IN VARCHAR2,
p_value IN VARCHAR2)
RETURN INTEGER IS
l_top_last INTEGER := Get_List_Element_Count(p_item);
l_index INTEGER := l_top_last / 2;
l_bottom_last INTEGER := 0;
BEGIN
IF l_top_last = 0
THEN
Return 0;
END IF;
--
WHILE Get_List_Element_Label(p_item,l_index) != p_value
AND l_index != l_top_last
AND l_index != l_bottom_last
LOOP
IF p_value < Get_List_Element_Label(p_item,l_index)
THEN
l_top_last := l_index;
l_index := (l_index - l_bottom_last) / 2;
ELSE
l_bottom_last := l_index;
l_index := l_index + ((l_top_last - l_index) / 2);
END IF;
END LOOP;
--
IF Get_List_Element_Label(p_item,l_index) = p_value
THEN
Return l_index;
ELSE
Return 0;
END IF;
END;[/tt]

In both of these cases, the functions will return 0 if they do not find a match for the label value you have entered. The binary search is more powerful if your list item has a large number of rows in it.

If you want to search for the value of the items in the list rather than the labels, use GET_LIST_ELEMENT_VALUE instaed of GET_LIST_ELEMENT_LABEL in the example code.


Let us know how you get on with it.