DataItemIterator Class Reference

DataItemIterator is a memory-efficient iterator class that can be used when rendering large data sets. More...

Inherits Iterator, Countable, and ArrayAccess.

Public Member Functions
	__construct ($query)
	count ()
	rewind ()
	current ()
	valid ()
	next ()
	key ()
	offsetExists ($offset)
	offsetGet ($offset)
	offsetSet ($offset, $value)
	offsetUnset ($offset)

Public Attributes
	$query
	$result
	$current = null
	$position = -1
	$item

Detailed Description

DataItemIterator is a memory-efficient iterator class that can be used when rendering large data sets.

With this iterator DataItems are retrieved from the database one at a time, rather than retrieving the full result set into memory all at once. It is a forward-only iterator, meaning it can be used in foreach(...) loops, but not for random access to the results. This class is not intended to be used directly by the programmer.

Author

andy

Definition at line 49 of file iterated_query.inc.

Constructor & Destructor Documentation

__construct()

DataItemIterator::__construct

(

$query

)

Definition at line 57 of file iterated_query.inc.

     {
          $this->query = $query;
          $this->item = new $this->query->class;       
     }

Member Function Documentation

count()

DataItemIterator::count

(

)

Definition at line 63 of file iterated_query.inc.

     {
          $this->rewind();
          trace("Row Count: {$this->query->rowCount}", 4);
          return $this->query->rowCount;          
     }

current()

DataItemIterator::current

(

)

Definition at line 88 of file iterated_query.inc.

     {
          $this->item->populate($this->current);
          return $this->item;
     }

key()

DataItemIterator::key

(

)

Definition at line 105 of file iterated_query.inc.

     {
          return $this->position;
     }

next()

DataItemIterator::next

(

)

Definition at line 99 of file iterated_query.inc.

     {
          $this->current = $this->result->fetch();
          ++$this->position;
     }

offsetExists()

DataItemIterator::offsetExists

(

$offset

)

Definition at line 110 of file iterated_query.inc.

     {
          if (!is_numeric($offset)) return false;
          return ($offset >= 0 && $offset < $this->query->rowCount);       
     }

offsetGet()

DataItemIterator::offsetGet

(

$offset

)

Definition at line 116 of file iterated_query.inc.

     {
          if ($offset == $this->position) return $this->item;
          
          if ($offset < $this->position)
          {
               $this->rewind();
          }
          else
          {
               $offset -= $this->position;
          }
          
          while($offset--)
          {
               $this->next();
          }
          return $this->item;
     }

offsetSet()

DataItemIterator::offsetSet	(		$offset,
			$value
	)

Definition at line 136 of file iterated_query.inc.

     {
          throw new FakoliException("Attempt to write to iterated data query");
     }

offsetUnset()

DataItemIterator::offsetUnset

(

$offset

)

Definition at line 141 of file iterated_query.inc.

     {
          throw new FakoliException("Attempt to write to iterated data query");
     }

rewind()

DataItemIterator::rewind

(

)

Definition at line 70 of file iterated_query.inc.

     {
          if ($this->position == 0) return;
          
          $this->current = null;
          $this->position = 0;
          
          try
          {
               $this->result = $this->query->_runQuery();
               $this->current = $this->result->fetch();
          }
          catch(PDOException $e)
          {
               throw new FakoliException($e->getMessage());
          }
     }

valid()

DataItemIterator::valid

(

)

Definition at line 94 of file iterated_query.inc.

     {
          return ($this->current != null);
     }

Member Data Documentation

$current

DataItemIterator::$current = null

Definition at line 53 of file iterated_query.inc.

$item

DataItemIterator::$item

Definition at line 55 of file iterated_query.inc.

$position

DataItemIterator::$position = -1

Definition at line 54 of file iterated_query.inc.

$query

DataItemIterator::$query

Definition at line 51 of file iterated_query.inc.

$result

DataItemIterator::$result

Definition at line 52 of file iterated_query.inc.

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The documentation for this class was generated from the following file:

• C:/code/cms.sonjara.com/framework/iterated_query.inc