xPDO.getIterator
Last updated Apr 20th, 2021 | Page history | Improve this page | Report an issue
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Learn morexPDO::getIterator¶
Retrieves an xPDOIterator
representing an iterable collection of xPDOObjects
by the specified xPDOCriteria
.
Use an xPDOIterator
to loop over large result sets and work with one instance at a time. This greatly reduces memory usage over loading the entire collection of objects into memory at one time. It is also slightly faster.
Syntax¶
API Docs: https://api.modx.com/revolution/2.2/db_core_xpdo_xpdo.class.html#\xPDO::getIterator()
xPDOIterator getIterator (string $className, [xPDOCriteria|array|str|int $criteria = null], [bool|int $cacheFlag = true])
Remember, if you are using xPDO map and class files that were generated from XML schema, the classname is not the same as your table name. If in doubt, have a look at the schema XML file, e.g.
<object class="MyClassName" table="my_class_name" extends="xPDOObject">
Example¶
Get an iterator for a collection of Box objects with a width of 40.
$boxes = $xpdo->getIterator('Box',array(
'width' => 40,
));
foreach ($boxes as $idx => $box) {
echo "Box #{$idx} has an id of {$box->get('id')} and a width of {$box->get('width')}\n";
}
If no matching xPDOObjects are found, the xPDOIterator object will be empty but will still be an object, so the following won't work (opposed to xPDO.getCollection):
// a parent of -1 doesn't exist, this is intentional =)
$resourceObjs = $xpdo->getIterator('modResource', array('parent' => -1));
if ($resourceObjs) { // the same goes for if (!empty($resourceObjs)
// this will always run, as the $resourceObjs is never empty
// in the sense we would intuitively think of empty
// the $resourceObjs contains an empty xPDOIterator object, but it's not an empty array!
}
// if you really need to check if there's something to iterate, you could do either:
if ($xpdo->getCount('modResource', array('parent' => -1))) {
// this will not run
}
// or
$resourceObjs->rewind();
if ($resourceObjs->valid()) {
// this will not run
}
See Also¶
Support the team building MODX with a monthly donation.
The budget raised through OpenCollective is transparent, including payouts, and any contributor can apply to be paid for their work on MODX.
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Learn more