You are viewing a plain text version of this content. The canonical link for it is here.
Posted to users@wicket.apache.org by pixotec <ra...@pixotec.de> on 2007/09/21 12:55:46 UTC
LinkTree lazy loading possible?
I want to use LinkTree to represent a very very large hierarchy (the loading
of the whole thing is expensive...).
Is there an AJAX way of loading the children of a node just when clicking on
the "plus-icon" for expanding?
--
View this message in context: http://www.nabble.com/LinkTree-lazy-loading-possible--tf4493231.html#a12814684
Sent from the Wicket - User mailing list archive at Nabble.com.
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
For additional commands, e-mail: users-help@wicket.apache.org
Re: LinkTree lazy loading possible?
Posted by Matej Knopp <ma...@gmail.com>.
Heh, sorry, didn't read the entire question. This seems to be the
right approach.
-Matej
On 9/21/07, swaroop belur <sw...@gmail.com> wrote:
>
>
> Initially when building the tree , just add a single child node to each
> first level of nodes u show
> You can mark this node as a "indicator node" or a "busy node" - this will
> allow the + sign to come
> up for the actual node. When u click on the + sign , representing the actual
> node , just
> remove the busy/ indicator node after all the actual children have been
> added ...(also just check if the indicator node is the only child - this
> way u will avoid another database hit for the second open click
> for the same node.)
>
>
>
>
>
> pixotec wrote:
> >
> > I want to use LinkTree to represent a very very large hierarchy (the
> > loading of the whole thing is expensive...).
> > Is there an AJAX way of loading the children of a node just when clicking
> > on the "plus-icon" for expanding?
> >
> >
>
> --
> View this message in context: http://www.nabble.com/LinkTree-lazy-loading-possible--tf4493231.html#a12814930
> Sent from the Wicket - User mailing list archive at Nabble.com.
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>
>
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
For additional commands, e-mail: users-help@wicket.apache.org
Re: LinkTree lazy loading possible?
Posted by Matej Knopp <ma...@gmail.com>.
Well, actually, I'm not sure how this would work, as you'd have to
load the children asynchronously and then update the tree. That
certainly isn't a trivial thing. I guess it would be better to replace
the link with an indicatingajaxlink or something like that.
-Matej
On 9/21/07, swaroop belur <sw...@gmail.com> wrote:
>
>
> Initially when building the tree , just add a single child node to each
> first level of nodes u show
> You can mark this node as a "indicator node" or a "busy node" - this will
> allow the + sign to come
> up for the actual node. When u click on the + sign , representing the actual
> node , just
> remove the busy/ indicator node after all the actual children have been
> added ...(also just check if the indicator node is the only child - this
> way u will avoid another database hit for the second open click
> for the same node.)
>
>
>
>
>
> pixotec wrote:
> >
> > I want to use LinkTree to represent a very very large hierarchy (the
> > loading of the whole thing is expensive...).
> > Is there an AJAX way of loading the children of a node just when clicking
> > on the "plus-icon" for expanding?
> >
> >
>
> --
> View this message in context: http://www.nabble.com/LinkTree-lazy-loading-possible--tf4493231.html#a12814930
> Sent from the Wicket - User mailing list archive at Nabble.com.
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>
>
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
For additional commands, e-mail: users-help@wicket.apache.org
Re: LinkTree lazy loading possible?
Posted by swaroop belur <sw...@gmail.com>.
Initially when building the tree , just add a single child node to each
first level of nodes u show
You can mark this node as a "indicator node" or a "busy node" - this will
allow the + sign to come
up for the actual node. When u click on the + sign , representing the actual
node , just
remove the busy/ indicator node after all the actual children have been
added ...(also just check if the indicator node is the only child - this
way u will avoid another database hit for the second open click
for the same node.)
pixotec wrote:
>
> I want to use LinkTree to represent a very very large hierarchy (the
> loading of the whole thing is expensive...).
> Is there an AJAX way of loading the children of a node just when clicking
> on the "plus-icon" for expanding?
>
>
--
View this message in context: http://www.nabble.com/LinkTree-lazy-loading-possible--tf4493231.html#a12814930
Sent from the Wicket - User mailing list archive at Nabble.com.
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
For additional commands, e-mail: users-help@wicket.apache.org
Re: LinkTree lazy loading possible?
Posted by MikeyG <mi...@meph.net>.
Actually I was over complicating it. The following work better:
@Override
protected void onJunctionLinkClicked(AjaxRequestTarget target, TreeNode
node) {
// expand the next level of the model
modelChanging();
if (isNodeExpanded(node)) { // node has already been (un)expanded
for this cycle
m_dataProvider.expand((DefaultMutableTreeNode)node, 1);
} else {
// otherwise delete the children and replace with our marker
node
m_dataProvider.expand((DefaultMutableTreeNode)node, 0);
}
// trigger redraw of clicked node
treeNodesChanged(new TreeModelEvent(this, new
TreePath(node.getParent()), new int[]{0}, new TreeNode[]{node} ));
modelChanged();
super.onJunctionLinkClicked(target, node);
}
--
View this message in context: http://www.nabble.com/LinkTree-lazy-loading-possible--tf4493231.html#a12923108
Sent from the Wicket - User mailing list archive at Nabble.com.
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
For additional commands, e-mail: users-help@wicket.apache.org
Re: LinkTree lazy loading possible?
Posted by MikeyG <mi...@meph.net>.
Hi
I've tried both solutions offered here do the same thing however to force
the nodes to be redrawn you need to call treeNodesChanged() - which in turn
adds the right components to the ajax target.
Unfortunately the api is a bit awkward and uses Enumerations. Here's my
solution which seems to work:
@Override
protected void onJunctionLinkClicked(AjaxRequestTarget target, TreeNode
node) {
// keep current list of children to mark changes
Set<TreeNode> nodeChanges = new HashSet<TreeNode>();
for (TreeNode treeNode :
CollectionUtils.makeIterable((Enumeration<TreeNode>)node.children())) {
nodeChanges.add(treeNode);
}
// expand the next level of the model
modelChanging();
if (isNodeExpanded(node)) { // node has already been (un)expanded
for this cycle
m_dataProvider.expand((DefaultMutableTreeNode)node, 1);
} else {
// otherwise delete the children and replace with our marker
node to save memory
m_dataProvider.expand((DefaultMutableTreeNode)node, 0);
}
// compile list of added and removed nodes
Enumeration<TreeNode> children = node.children();
while (children.hasMoreElements()) {
TreeNode treeNode = children.nextElement();
if (nodeChanges.contains(treeNode)) {
nodeChanges.remove(treeNode);
} else {
nodeChanges.add(treeNode);
}
}
modelChanged();
// need array of ints to match changed node list
int nchanges = nodeChanges.size();
int[] indices = new int[nchanges];
for (int i = 0; i < nchanges; ++i) {
indices[i] = i;
}
// trigger redraw of clicked node's changed children
treeNodesChanged(new TreeModelEvent(this, new TreePath(node),
indices, nodeChanges.toArray() ));
super.onJunctionLinkClicked(target, node);
}
(m_dataProvider.expand(node, depth) adds children or replaces them with a
marker node as appropriate.)
Hope that helps :-)
MikeG
--
View this message in context: http://www.nabble.com/LinkTree-lazy-loading-possible--tf4493231.html#a12921685
Sent from the Wicket - User mailing list archive at Nabble.com.
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
For additional commands, e-mail: users-help@wicket.apache.org
Re: LinkTree lazy loading possible?
Posted by Kent Tong <ke...@cpttm.org.mo>.
pixotec wrote:
>
> I want to use LinkTree to represent a very very large hierarchy (the
> loading of the whole thing is expensive...).
> Is there an AJAX way of loading the children of a node just when clicking
> on the "plus-icon" for expanding?
>
You may try my code below which seems to work, even though it's not using
ajax:
<pre>
public class TreePage extends WebPage {
private DefaultTreeModel treeModel;
private TreeChildrenProvider provider;
private class MyTreeNode extends DefaultMutableTreeNode {
public MyTreeNode(String nodeName) {
super(nodeName);
}
public String getName() {
return (String) getUserObject();
}
public boolean isLeaf() {
return provider.getChildren(getName()).isEmpty();
}
}
public TreePage() {
provider = makeMockProvider();
MyTreeNode a = new MyTreeNode("a");
treeModel = new DefaultTreeModel(a);
LinkTree tree = new LinkTree("tree", new PropertyModel(this,
"treeModel"));
add(tree);
ITreeState treeState = tree.getTreeState();
treeState.collapseAll();
treeState.addTreeStateListener(new ITreeStateListener() {
public void nodeUnselected(TreeNode node) {
}
public void nodeSelected(TreeNode node) {
}
public void nodeExpanded(TreeNode node) {
if (!node.isLeaf() && node.getChildCount() == 0) {
MyTreeNode myTreeNode = ((MyTreeNode) node);
for (String childName : provider.getChildren(myTreeNode
.getName())) {
myTreeNode.add(new MyTreeNode(childName));
}
}
}
public void nodeCollapsed(TreeNode node) {
}
public void allNodesExpanded() {
}
public void allNodesCollapsed() {
}
});
}
private TreeChildrenProvider makeMockProvider() {
return new TreeChildrenProvider() {
public List<String> getChildren(String nodeName) {
if (nodeName.equals("a")) {
return Arrays.asList(new String[] { "b", "c" });
}
if (nodeName.equals("b")) {
return Arrays.asList(new String[] { "d", "e" });
}
return Collections.EMPTY_LIST;
}
};
}
public DefaultTreeModel getTreeModel() {
return treeModel;
}
}
public interface TreeChildrenProvider {
List<String> getChildren(String nodeName);
}
</pre>
--
View this message in context: http://www.nabble.com/LinkTree-lazy-loading-possible--tf4493231.html#a12842551
Sent from the Wicket - User mailing list archive at Nabble.com.
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
For additional commands, e-mail: users-help@wicket.apache.org
Re: LinkTree lazy loading possible?
Posted by Matej Knopp <ma...@gmail.com>.
Of course. You just need to implement proper TreeModel that lazily
loads children.
-Matej
On 9/21/07, pixotec <ra...@pixotec.de> wrote:
>
> I want to use LinkTree to represent a very very large hierarchy (the loading
> of the whole thing is expensive...).
> Is there an AJAX way of loading the children of a node just when clicking on
> the "plus-icon" for expanding?
>
> --
> View this message in context: http://www.nabble.com/LinkTree-lazy-loading-possible--tf4493231.html#a12814684
> Sent from the Wicket - User mailing list archive at Nabble.com.
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>
>
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
For additional commands, e-mail: users-help@wicket.apache.org