Comments on: Working With Recursive Data Part II: Tree Traversal http://www.phpbbdoctor.com/blog/2008/08/02/working-with-recursive-data-part-ii-tree-traversal/ Your premium source for custom modification services for phpBB Mon, 09 Aug 2010 18:09:31 -0500 http://wordpress.org/?v=2.8.4 hourly 1 By: Dave Rathbun http://www.phpbbdoctor.com/blog/2008/08/02/working-with-recursive-data-part-ii-tree-traversal/comment-page-1/#comment-2930 Dave Rathbun Fri, 21 Nov 2008 14:50:52 +0000 http://www.phpbbdoctor.com/blog/?p=226#comment-2930 Hi, Aftab, no... you don't have to draw it out. :) A tree starts with only a root node. The left and right are 1 and 2. As you add a node to the tree, you determine where it is to be inserted and run a fairly simple insert routine. The insert routine consists of an update statement and an insert statement. The update is to increment the left and right values for all nodes that will be beyond the new node in the tree. There are other maintenance routines run when you delete a node. Moving a node is a call to the delete and then the insert process, so there is no special code for that. I will create another blog post to answer this question. Hi, Aftab, no… you don’t have to draw it out. :) A tree starts with only a root node. The left and right are 1 and 2. As you add a node to the tree, you determine where it is to be inserted and run a fairly simple insert routine. The insert routine consists of an update statement and an insert statement. The update is to increment the left and right values for all nodes that will be beyond the new node in the tree.

There are other maintenance routines run when you delete a node. Moving a node is a call to the delete and then the insert process, so there is no special code for that.

I will create another blog post to answer this question.

]]> By: Aftab http://www.phpbbdoctor.com/blog/2008/08/02/working-with-recursive-data-part-ii-tree-traversal/comment-page-1/#comment-2929 Aftab Fri, 21 Nov 2008 10:40:21 +0000 http://www.phpbbdoctor.com/blog/?p=226#comment-2929 Hi So to workout the left and right values I have to first draw it out and then run a line around it. How does this work in the real world? Assigning the left and right values in this way just isn't practical. Thanks Hi

So to workout the left and right values I have to first draw it out and then run a line around it. How does this work in the real world? Assigning the left and right values in this way just isn’t practical.

Thanks

]]> By: Dave Rathbun http://www.phpbbdoctor.com/blog/2008/08/02/working-with-recursive-data-part-ii-tree-traversal/comment-page-1/#comment-2705 Dave Rathbun Sat, 02 Aug 2008 20:52:25 +0000 http://www.phpbbdoctor.com/blog/?p=226#comment-2705 Hi, Micheal, it seems we're both making the "blog rounds" today. :lol: The next post I'm working on in this series is going to show (in pseudo-code) how I manage the tree structure. I have functions called add_node() and delete_node() and move_node() and so on. By setting up these functions it becomes very easy to manage the tree data. No doubt there is something very similar in phpBB3. Hi, Micheal, it seems we’re both making the “blog rounds” today. :lol:

The next post I’m working on in this series is going to show (in pseudo-code) how I manage the tree structure. I have functions called add_node() and delete_node() and move_node() and so on. By setting up these functions it becomes very easy to manage the tree data. No doubt there is something very similar in phpBB3.

]]> By: Micheal http://www.phpbbdoctor.com/blog/2008/08/02/working-with-recursive-data-part-ii-tree-traversal/comment-page-1/#comment-2704 Micheal Sat, 02 Aug 2008 20:36:42 +0000 http://www.phpbbdoctor.com/blog/?p=226#comment-2704 My brain hurts. :P Funnily enough, I may just have to make use of this in one of my projects. Not looking forward to it. At least now I get why phpBB3 does this. :) My brain hurts. :P Funnily enough, I may just have to make use of this in one of my projects. Not looking forward to it. At least now I get why phpBB3 does this. :)

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