Tree: ezcTreeNodeListIterator
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Class: ezcTreeNodeListIterator
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ezcTreeNodeListIterator implements an iterator over an ezcTreeNodeList. [
source]
Implemented Interfaces
- Iterator (internal interface)
The iterator is instantiated with both an implementation of an ezcTree and an ezcTreeNodeList object. It can be used to iterate over all the nodes in a list.
Example:
1. <?php
2. // fetch all the nodes in a subtree as an ezcNodeList
3. $nodeList = $tree->fetchSubtree( 'pan' );
4. foreach ( new ezcTreeNodeListIterator( $tree, $nodeList ) as $nodeId => $data )
5. {
6. // do something with the node ID and data - data is fetched on
7. // demand
8. }
9. ?>
Data for the nodes in the node lists is fetched on demand, unless the "prefetch" argument is set to true. In that case the iterator will fetch the data when the iterator is instantiated. This reduces the number of queries made for database and persistent object based data stores, but increases memory usage.
Example:
1. <?php
2. // fetch all the nodes in a subtree as an ezcNodeList
3. $nodeList = $tree->fetchSubtree( 'Uranus' );
4. // instantiate an iterator with pre-fetching enabled
5. foreach ( new ezcTreeNodeListIterator( $tree, $nodeList, true ) as $nodeId => $data )
6. {
7. // do something with the node ID and data - data is fetched when
8. // the iterator is instatiated.
9. }
10. ?>
Method Summary
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public ezcTreeNodeListIterator |
__construct(
$tree, $nodeList, [$prefetch = false] )
Constructs a new ezcTreeNodeListIterator object over $nodeList. |
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public mixed |
current(
)
Returns the data belonging to the current node, and fetches the data in case on-demand fetching is required. |
|
public string |
key(
)
Returns the node ID of the current node. |
|
public void |
next(
)
Advances the internal pointer to the next node in the nodelist. |
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public void |
rewind(
)
Rewinds the internal pointer back to the start of the nodelist. |
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public bool |
valid(
)
Returns whether the internal pointer is still valid. |
Methods
__construct
Constructs a new ezcTreeNodeListIterator object over $nodeList.
The $tree argument is used so that data can be fetched on-demand.
Parameters
current
mixed current(
)
Returns the data belonging to the current node, and fetches the data in case on-demand fetching is required.
key
string key(
)
Returns the node ID of the current node.
next
void next(
)
Advances the internal pointer to the next node in the nodelist.
rewind
void rewind(
)
Rewinds the internal pointer back to the start of the nodelist.
valid
bool valid(
)
Returns whether the internal pointer is still valid.
It returns false when the end of list has been reached.
Last updated: Mon, 30 Mar 2009
