Tree structure project

Files

index.php

• It is the entrance of the Application.
• It requires NodeHandler.php and new object NodeHandler creates there.
• At the top of the code block the possible realization of the inserting and deleting of nodes is presented under comments.
• Inside <!-- Tree structure --> block of html there are $nodes->showTree() and $nodes->showTree(3) that provides representation of Nodes Tree in two modes:
  • $nodes->showTree() show the whole Tree of Nodes,
  • $nodes->showTree(3) show the part of Tree of Nodes limited by node with $id = 3.

main.css

• This is the main stylesheet of the application.

App/DbConnector.php

• Provides connection to Database via singleton pattern.
• Parameters for connection stores in properties of the class DbConnector:
  • $host for host name,
  • $db_name for name of the Database,
  • $user for login,
  • $pass for password.
• Main methods are:
  • getInstance() for class DbConnector,
  • getConnection() for PDO Object.

App/Model.php

• This file store class Model to perform the operations with DB.
• Main methods are:
  • getNodes() to show show whole tree of nodes or its part,
  • setNode() to add new node to the tree,
  • deleteNode() to delete node from tree.

App/NodeHandler.php

• This method gives the representation of nodes to page index.php.
• Main methods are:
  • showTree() to echo the whole tree of nodes or its part if parameter is provided,
  • addNewNode() to add now node to Database via Model.php to the root or specified level,
  • deleteNode() to delete node from Database via Model.php from the specified level or to delete the whole tree.

tree-structure-example.sql

• This is the dump of the tables of my local tree-structure Database.
• It is partly filled for example.

Database structure

• Data stores via Nested Sets method.
• For example is provided a catalogue (of cars) in such hierarchy:
• vehicle
  • Type (Motorcycle, Automobile)
    • Brand (Audi, BMW, Ford)
      • Model (A1, A2, Focus, etc.)
        • Year (1999, 2003, etc.)
• All nodes are nested on correspond levels.
• New root level near vehicle can be added. For example, animal with its own hierarchy of nodes, but bonded with near root node by right_key and left_key.