doc/tree.txt

   1 So what is this tree stuff?
   2 ===========================
   3
   4 In order to get correct folder deletion across the board for all
   5 different RFC2060 compliant IMAP servers, deleting of folders
   6 needed to work by deleting subfolders (inferiors) first, working
   7 up to the top folder that is desired to be deleted.
   8
   9 The best way to do this was to use a tree, and walk the thing in
  10 preorder to get subfolders first (leaves), working our way up the
  11 tree.  I chose to use an array for the tree structure.
  12
  13 The array has the following elements:
  14 $tree[0]["value"]             = <full folder name>
  15 $tree[0]["doIHaveChildren"]   = boolean
  16 $tree[0]["subNodes"]          = indexes of the array that are
  17                                   child nodes of this node
  18
  19 The trickiest part was finding the correct parent node when creating
  20 a new node in the tree.  Check the documentation in the code for
  21 more info on this.
  22
  23 Basically all we had to do was loop through each of the items that
  24 need to be in the tree (folders, subfolders), find their parent,
  25 let their parent know it has a new child, and insert the values
  26 into the child.
  27
  28 Once the tree is generated, a simple preorder or postorder walk
  29 of the tree can be done doing whatever function you desire (delete,
  30 create, etc).
  31
  32 Preorder walking gives you the tree from the leaves up.  Postorder
  33 walks the tree from the root node down to the leaves.