OACS tutorial document reads like below
=============below==========================================
Once the category trees have been selected users need a way to categorize items. The easiest way to do this is by adding the category widget type of the form builder to note-edit.tcl. To achieve this we'll need to use the -extend switch to the ad_form command. Here's the "meat" of the note-edit.tcl page:
ad_form -name note -form {
{item_id:key}
{title:text {label Title}}
}
set package_id [ad_conn package_id]
set category_trees [category_tree::get_mapped_trees $package_id]
foreach tree $category_trees {
foreach { tree_id name subtree_id } $tree {}
ad_form -extend -name note -form \
[list [list category_id_${tree_id}:integer(category),optional \
{label $name} \
{html {single single}} \
{category_tree_id $tree_id} \
{category_subtree_id $subtree_id} \
{category_object_id {[value_if_exists entry_id]}}]]
}
========end of below=======================================
As like before, it generate a kind of chronicle error..
===========error start=====================================
Request Error
can't read "element(value)": no such element in array
while executing
"lindex $element(value) 0"
(procedure "template::widget::category" line 17)
invoked from within
"template::widget::$element(widget) element $tag_attributes"
(procedure "template::element::render" line 10)
invoked from within
"template::element::render note category_trees { }"
("eval" body line 1)
invoked from within
"eval template::element::$command $form_id $element_id $args"
(procedure "template::element" line 2)
invoked from within
"template::element render ${form:id} category_trees { } "
invoked from within
"append __adp_output "[template::element render ${form:id} category_trees { } ]""
("uplevel" body line 106)
invoked from within
"uplevel {
===============end of error================================
Also I beleive there are someone who can help me...
