Since tapestry's tree is ajax enabled... you will need to modify the code
slightly (db structure can remain the same). Instead of getting the entire
tree, you will get a single node and it's first level children for each
ajax request.
On Tuesday, 7 February 2012, Lance Java <lance.j...@googlemail.com> wrote:
> I have done similar things in the past using a flat database structure to
build a nested structure.
>
> public class Node {
> private Integer nodeId; // stored in database
> private String description; // stored in database
> private Integer parentId; // stored in database
> private List<Node> childNodes = new ArrayList<Node>(); // calculated
using parentId
> }
>
> public class NodeService {
> private List<Node> getAllNodesUnjoined() {
> // get all records from the flat database table
> }
>
> // use the flat structure to build a nested structure
> public Node getTree() {
> List<Node> nodes = getAllNodesUnjoined();
> Map<Integer, Node> nodesById = new HashMap();
> Node rootNode = null;
> for (Node node : nodes) {
> if (node.getParentId() == null) {
> if (rootNode != null) {
> throw new RuntimeException("More than one root node
found");
> }
> rootNode = node;
> }
> nodesById.put(node.getNodeId(), node);
> }
> if (rootNode == null) {
> throw new RuntimeException("No root node found");
> }
> for (Node node : nodes) {
> if (node.getParentId() != null) {
> Node parent = nodesById.get(node.getParentId());
> parent.getChildNodes().add(node);
> }
> }
> return rootNode;
> }
> }
>
> On Tuesday, 7 February 2012, George Christman <gchrist...@cardaddy.com>
wrote:
>> Hello, I was wondering if someone could help point me in the right
direction
>> regarding the db and query needed to generate a database driven tree
grid.
>>
>> This is some code I found between Tapestry-Jquery and JumpStart. I'm not
>> sure what the best approach would be to generate this recursive query.
>>
>> Thanks in advance.
>>
>> static {
>> ROOT.addChild(
>> new TreeExample("Renault").addChild(
>> new TreeExample("Mégane")).addChild(
>> new TreeExample("Clio")
>> .addChildrenNamed("Clio Campus", "Clio Sport")))
>> .addChild(new
>> TreeExample("Ferarri").addChildrenNamed("F430", "California"));
>>
>>
>> TreeExample numbers = new TreeExample("Numbers");
>> for (int i = 0; i < 10000; i++) {
>> numbers.addChild(new
TreeExample(Integer.toString(i)));
>> }
>> ROOT.addChild(numbers);
>> }
>>
>> --
>> View this message in context:
http://tapestry.1045711.n5.nabble.com/Tapestry-TreeGrid-tp5462126p5462126.html
>> Sent from the Tapestry - User mailing list archive at Nabble.com.
>>
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>>
