I ran into the excellent jstree jQuery UI plug in this morning. In a word - great! It is easy to use, easy to style & does what it says on the box. The one thing I have not yet been able to figure out is this - in my app I want to ensure that only one node is expanded at any given time. i.e. when the user clicks on the + button and expands a node, any previously expanded node should silently be collapsed. I need to do this in part to prevent the container div for a rather lengthy tree view from creating an ugly scrollbar on overflow and also to avoid "choice overload" for the user.
I imagine that there is some way of doing this but the good but rather terse jstree documentation has not helped me to identify the right way to do this. I would much appreciate any help.
jsTree is great but its documentation is rather dense. I eventually figured it out so here is the solution for anyone running into this thread.
Firstly, you need to bind the open_node event to the tree in question. Something along the lines of
$("tree").jstree({"themes":objTheme,"plugins":arrPlugins,"core":objCore}).
bind("open_node.jstree",function(event,data){closeOld(data)});
i.e. you configure the treeview instance and then bind the open_node event. Here I am calling the closeOld function to do the job I require - close any other node that might be open. The function goes like so
function closeOld(data)
{
var nn = data.rslt.obj;
var thisLvl = nn;
var levels = new Array();
var iex = 0;
while (-1 != thisLvl)
{
levels.push(thisLvl);
thisLvl = data.inst._get_parent(thisLvl);
iex++;
}
if (0 < ignoreExp)
{
ignoreExp--;
return;
}
$("#divElements").jstree("close_all");
ignoreExp = iex;
var len = levels.length - 1;
for (var i=len;i >=0;i--) $('#divElements').jstree('open_node',levels[i]);
}
This will correctly handle the folding of all other nodes irrespective of the nesting level of the node that has just been expanded.
A brief explanation of the steps involved