datamanager.class.php

ProjectPier 源码 很好的项目管理程序

<?php
  
  /**
  * Data manager class
  *
  * This class implements methods for managing data objects, database rows etc. One 
  * of its features is automatinc caching of loaded data.
  *
  * @package System
  * @version 1.0
  * @http://www.projectpier.org/
  * 
  */
  abstract class DataManager {
  
    /**
    * Database table where items are saved
    *
    * @var string
    */
    private $table_name;
    
    /**
    * Item cache array
    *
    * @var array
    */
    private $cache = array();
    
    /**
    * Class of items that this manager is handling
    *
    * @var string
    */
    private $item_class = '';
    
    /**
    * Cache items
    *
    * @var boolean
    */
    private $caching = true;
    
    /**
    * Construct and set item class
    *
    * @access public
    * @param string $item_class Value of class of items that this manager is handling
    * @param string $table Table where data is stored
    * @param boolean $caching Caching stamp value
    * @return DataManager
    */
    function __construct($item_class, $table_name, $caching = true) {
      $this->setItemClass($item_class);
      $this->setTableName($table_name);
      $this->setCaching($caching);
    } // end func __construct
    
    // ---------------------------------------------------
    //  Definition methods
    // ---------------------------------------------------
    
    /**
    * Return array of object columns
    *
    * @access public
    * @param void
    * @return array
    */
    abstract function getColumns();
    
    /**
    * Return column type
    *
    * @access public
    * @param string $column_name
    * @return string
    */
    abstract function getColumnType($column_name);
    
    /**
    * Return array of PK columns. If only one column is PK returns its name as string
    *
    * @access public
    * @param void
    * @return array or string
    */
    abstract function getPkColumns();
    
    /**
    * Return name of first auto_incremenent column if it exists
    *
    * @access public
    * @param void
    * @return string
    */
    abstract function getAutoIncrementColumn();
    
    /**
    * Return array of lazy load columns
    *
    * @access public
    * @param void
    * @return array
    */
    function getLazyLoadColumns() {
      return array();
    } // getLazyLoadColumnss
    
    /**
    * Check if specific column is lazy load column
    *
    * @access public
    * @param string $column_name
    * @return boolean
    */
    function isLazyLoadColumn($column_name) {
      return in_array($column_name, $this->getLazyLoadColumns());
    } // isLazyLoadColumn
    
    /**
    * Return all columns that are not martked as lazy load
    *
    * @access public
    * @param boolean $escape_column_names
    * @return array
    */
    function getLoadColumns($escape_column_names = false) {
      
      // Prepare
      $load_columns = array();
      
      // Loop...
      foreach ($this->getColumns() as $column) {
        if (!$this->isLazyLoadColumn($column)) {
          $load_columns[] = $escape_column_names ? DB::escapeField($column) : $column;
        } // if
      } // foreach
      
      // Done...
      return $load_columns;
      
    } // getLoadColumns
    
    // ---------------------------------------------------
    //  Finders
    // ---------------------------------------------------
    
    /**
    * Do a SELECT query over database with specified arguments
    *
    * @access public
    * @param array $arguments Array of query arguments. Fields:
    * 
    *  - one - select first row
    *  - conditions - additional conditions
    *  - order - order by string
    *  - offset - limit offset, valid only if limit is present
    *  - limit
    * 
    * @return one or many objects
    * @throws DBQueryError
    */
    function find($arguments = null) {
      
      // Collect attributes...
      $one        = (boolean) array_var($arguments, 'one', false);
      $conditions = $this->prepareConditions( array_var($arguments, 'conditions', '') );
      $order_by   = array_var($arguments, 'order', '');
      $offset     = (integer) array_var($arguments, 'offset', 0);
      $limit      = (integer) array_var($arguments, 'limit', 0);
      
      // Prepare query parts
      $where_string = trim($conditions) == '' ? '' : "WHERE $conditions";
      $order_by_string = trim($order_by) == '' ? '' : "ORDER BY $order_by";
      $limit_string = $limit > 0 ? "LIMIT $offset, $limit" : '';
      
      // Prepare SQL
      $sql = "SELECT * FROM " . $this->getTableName(true) . " $where_string $order_by_string $limit_string";
      
      // Run!
      $rows = DB::executeAll($sql);
      
      // Empty?
      if (!is_array($rows) || (count($rows) < 1)) {
        return null;
      } // if
      
      // If we have one load it, else loop and load many
      if ($one) {
        return $this->loadFromRow($rows[0]);
      } else {
        $objects = array();
        foreach ($rows as $row) {
          $object = $this->loadFromRow($row);
          if (instance_of($object, $this->getItemClass())) {
            $objects[] = $object;
          } // if
        } // foreach
        return count($objects) ? $objects : null;
      } // if
    } // find
    
    /**
    * Find all records
    *
    * @access public
    * @param array $arguments
    * @return array
    */
    function findAll($arguments = null) {
      if (!is_array($arguments)) {
        $arguments = array();
      } // if
      $arguments['one'] = false;
      return $this->find($arguments);
    } // findAll
    
    /**
    * Find one specific record
    *
    * @access public
    * @param array $arguments
    * @return array
    */
    function findOne($arguments = null) {
      if (!is_array($arguments)) {
        $arguments = array();
      } // if
      $arguments['one'] = true;
      return $this->find($arguments);
    } // findOne
    
    /**
    * Return object by its PK value
    *
    * @access public
    * @param mixed $id
    * @param boolean $force_reload If value of this variable is true cached value
    *   will be skipped and new data will be loaded from database
    * @return object
    */
    function findById($id, $force_reload = false) {
      return $this->load($id, $force_reload);
    } // findById
    
    /**
    * Return number of rows in this table
    *
    * @access public
    * @param string $conditions Query conditions
    * @return integer
    */
    function count($conditions = null) {
      // Don't do COUNT(*) if we have one PK column
      $escaped_pk = is_array($pk_columns = $this->getPkColumns()) ? '*' : DB::escapeField($pk_columns);
      
      $conditions = $this->prepareConditions($conditions);
      $where_string = trim($conditions) == '' ? '' : "WHERE $conditions";
      $row = DB::executeOne("SELECT COUNT($escaped_pk) AS 'row_count' FROM " . $this->getTableName(true) . " $where_string");
      return (integer) array_var($row, 'row_count', 0);
    } // count
    
    /**
    * Delete rows from this table that match specific conditions
    *
    * @access public
    * @param string $conditions Query conditions
    * @return boolean
    */
    function delete($conditions = null) {
      $conditions = $this->prepareConditions($conditions);
      $where_string = trim($conditions) == '' ? '' : "WHERE $conditions";
      return DB::execute("DELETE FROM " . $this->getTableName(true) . " $where_string");
    } // delete
    
    /**
    * This function will return paginated result. Result is array where first element is 
    * array of returned object and second populated pagination object that can be used for 
    * obtaining and rendering pagination data using various helpers.
    * 
    * Items and pagination array vars are indexed with 0 for items and 1 for pagination
    * because you can't use associative indexing with list() construct
    *
    * @access public
    * @param array $arguments Query argumens (@see find()) Limit and offset are ignored!
    * @param integer $items_per_page Number of items per page
    * @param integer $current_page Current page number
    * @return array
    */
    function paginate($arguments = null, $items_per_page = 10, $current_page = 1) {
      if (!is_array($arguments)) {
        $arguments = array();
      } // if
      $conditions = array_var($arguments, 'conditions');
      $pagination = new DataPagination($this->count($conditions), $items_per_page, $current_page);
      
      $arguments['offset'] = $pagination->getLimitStart();
      $arguments['limit'] = $pagination->getItemsPerPage();
      
      $items = $this->findAll($arguments);
      return array($items, $pagination);
    } // paginate
    
    /**
    * Get conditions as argument and return them in the string (if array walk through and escape values)
    *
    * @param mixed $conditions
    * @return string
    */
    function prepareConditions($conditions) {
      if (is_array($conditions)) {
        $conditions_sql = array_shift($conditions);
        $conditions_arguments = count($conditions) ? $conditions : null;
        return DB::prepareString($conditions_sql, $conditions_arguments);
      } // if
      return $conditions;
    } // prepareConditions
    
    /**
    * Load specific item. If we can't load data return NULL, else return item object
    *
    * @access public
    * @param mixed $id Item ID
    * @param boolean $force_reload If this value is true cached value (if set) will be skipped
    *   and object data will be loaded from database
    * @return DataObject
    */
    function load($id, $force_reload = false) {