Information about SQL trees:
http://dev.e-taller.net/dbtree/
=> a bit of inspiration…
* PEAR Tree Package
Modified Preorder Tree Traversal (or Nested Sets) tree model
To install, just unzip the file into your app dir. (you can delete the manual folder if you want, it isn’t needed, neither is the custom loader (can be handy though)).
Load the model with $this->load->model(’MPTtree’), and then set the table name with $this->MPTtree->set_table(’tablename’)
Check the comments in file or the accompanying html manual on how to use the model.
Download
Thread: http://codeigniter.com/forums/viewthread/74114/
A simple admin interface (supports moving, deleting and insertion of nodes (editing you have to implement yourselves)):
Author
Martin Wernstahl <m4rw3r at gmail dot com>
License
MPTtree is licensed under LGPL
Change Log
Version 0.1.6-fix
Release Date: March 27, 2008
Fixed error with call to db::get_where() in move_node()
Corrected return values from move_node(), now it returns a normal array, just like insert_node()
tree2array() now returns false if the root node cannot be found
Added some debug messages
Renamed MPTtree.php to mpttree.php to avoid include errors under linux
Minor corrections in the manual
Version 0.1.6
Release Date: March 22, 2008
Added tree2array()
Added get_descendants_wlevel()
Added has_children()
Added has_children() to ORM object
Added command swith to get_descendants() to make it call get_descendants_wlevel() instead, thus returning a level column
get_ORM() can now also accept a path (string or array doesn’t matter) to the node which to load.
Version 0.1.5
Release Date: March 13, 2008
Introducing an ORM wrapper for MPTtree
Added a MPTtreeIterator, to iterate over descendants in the tree
Added a MPTtreeORMIterator, to iterate over descendants in the tree, returning ORM objects
Added get_node_byid()
Added an (optional) custom MY_Loader.php, to make it easier to have multiple instances at the same time (no need extending classes).
Improved get_parent()
Improved count_children(), not as much database traffic and counting is done in database
Improved xpath(), more accurate (doesn’t need xpath2() anymore)
Changed the return values from the insert and move methods to return the new lft and rgt values instead of true.
xpath() and xpath2() can now also accept an array as path (no need using separators)
Version 0.1.4
Release Date: February 26, 2008
Added a few methods to be used with Active Record, see Active Record helpers
Added calls to db::protect_identifiers() in set_opts() and in set_table()
Replaced the method xpath() with a much more efficient xpath variant.
The old xpath() method have been renamed to path2().
HCG: Replaced use of transactions with locks
Version 0.1.2
Release Date: February 20, 2008
Added the method xpath()
Remade set_opts() to accept an array with the parameters
Added a sanitation of the data to update_node() and to the insert methods. This to prevent damage to the tree.
Version 0.1.1
Release Date: February 18, 2008
Added transaction support
Added the method get_descendants_where()
Added the method get_children_where()
Changed algohrithm for get_children(), the new is almost twice as fast as the old one!
Renamed some internal properties to address some conflicts with different CI libraries
Changed name of get_decendants() to get_descendants(), a bad misspelling by me.
Version 0.1.0
Release Date: February 9, 2008
Initial Release
Thanks To:
Hamish Guthrie <hamish at prodigi dot ch> (Table locking)