newish coder for OOP in PHP v5.4 and running into an odd snag. I have a function that recursively iterates through a hierarchy of objects, matches an object by its class type and its unique ID, and then returns it:
public function getChildObjectById($searchObj, $newObjType, $newObjId = 0) {
/* iterate through each child object in the array */
foreach($searchObj->getChildObjects() as $childObject) {
/* check if object is an instance of specified type */
if (is_object($childObject) && $childObject instanceof $newObjType) {
/* checks if the object id was matched */
$objFound = ($childObject->getId() == $newObjId);
if ($objFound) {
echo "*** found the object ***<br>";
echo "Found child object type: " . $newObjType . "<br>";
echo "id: " . $childObject->getId() . "<br>";
echo "<pre>";
print_r($childObject); // <-- object information populated here
echo "</pre>";
return ($childObject); // <-- lose it here
}
/**
* checks if the object has children. If so, recursively call function to continue
* searching the multidimensional array
*/
if (count($childObject->getChildObjects() > 0)) {
echo "child object has " . count($childObject->getChildObjects()) . " direct children:<br>";
echo "returning childObject:<br>";
echo "<pre>";
print_r($childObject); // <-- child object information populated here
echo "</pre>";
echo "retuning objtype: " . $newObjType . "<br>"; // <-- ItemGroup
echo "returning objId: " . $newObjId . "<br>"; // <-- 11
return $this->getChildObjectById($childObject, $newObjType, $newObjId);
} // as per suggestion added "return" to front of this call, still getting NULL and error message Fatal error: Call to a member function addChildObject() on a non-object on line 187
}
}
}
The function is called from this line:
$parentItemGroup = $newCollection->getChildObjectById($newCollection, 'ItemGroup', $parentId);
Now when I do a print_r on the $childObject within the getChildObjectById function I have the object I'm looking for and all its properties/values so the $childObject is defined properly and the search appears to be working. However, the next line where I try and return that back to the calling function somehow loses the object and doing a var_dump of $parentItemGroup expecting my object just results in NULL.
Is there enough here for someone to point out what I'm missing or do you need to see more code? Am I way off base here?
Thanks in advance for any assistance you can provide, and be gentle... I'm still learning! :)
Here's an example of the object array I'm working towards:
Collection Object
(
[id:DataObject:private] => 1
[properties:DataObject:private] => Array
(
[title] => Collection One
)
[childObjects:DataObject:private] => Array
(
[0] => Item Object
(
[id:DataObject:private] => 6
[properties:DataObject:private] => Array
(
[title] => Item Six
)
[childObjects:DataObject:private] => Array
(
)
)
[1] => Item Object
(
[id:DataObject:private] => 11
[properties:DataObject:private] => Array
(
[title] => Item Eleven
)
[childObjects:DataObject:private] => Array
(
)
)
[2] => Item Object
(
[id:DataObject:private] => 10
[properties:DataObject:private] => Array
(
[title] => Item Ten
)
[childObjects:DataObject:private] => Array
(
)
)
[3] => Item Object
(
[id:DataObject:private] => 14
[properties:DataObject:private] => Array
(
[title] => Item Fourteen
)
[childObjects:DataObject:private] => Array
(
)
)
[4] => ItemGroup Object
(
[id:DataObject:private] => 1
[properties:DataObject:private] => Array
(
[item_group_title] => 1
[item_group_depth] => 0
[item_group_parent_id] =>
)
[childObjects:DataObject:private] => Array
(
[0] => Item Object
(
[id:DataObject:private] => 7
[properties:DataObject:private] => Array
(
[title] => Item Seven
)
[childObjects:DataObject:private] => Array
(
)
)
[1] => Item Object
(
[id:DataObject:private] => 1
[properties:DataObject:private] => Array
(
[title] => Item One
)
[childObjects:DataObject:private] => Array
(
)
)
[2] => ItemGroup Object
(
[id:DataObject:private] => 5
[properties:DataObject:private] => Array
(
[item_group_title] => 1.4
[item_group_depth] => 1
[item_group_parent_id] => 1
)
[childObjects:DataObject:private] => Array
(
[0] => Item Object
(
[id:DataObject:private] => 2
[properties:DataObject:private] => Array
(
[title] => Item Two
)
[childObjects:DataObject:private] => Array
(
)
)
)
)
[3] => ItemGroup Object
(
[id:DataObject:private] => 2
[properties:DataObject:private] => Array
(
[item_group_title] => 1.1
[item_group_depth] => 1
[item_group_parent_id] => 1
)
[childObjects:DataObject:private] => Array
(
[0] => Item Object
(
[id:DataObject:private] => 8
[properties:DataObject:private] => Array
(
[title] => Item Eight
)
[childObjects:DataObject:private] => Array
(
)
)
)
)
)
)
)
)
$this->getChildObjectById($childObject, $newObjType, $newObjId);
You forgot to return the result of your recursive call
btw. boolean values are better used as booleans :)
$objFound = $childObject->getId() == $newObjId; // no need for ? TRUE : FALSE
EDIT:
Beside the missing return, there are other reasons your function might not work:
My gut feeling is that you are overdoing this. Why don't you assign a unique id to each object (regardless of its class)?
It looks like your search function is trying to kill two birds with one stone. A bit like if the id was a kind of index into your sub-structures, so that passing 0 (your default value) would allow to access the 1st record of a given type. It makes it complex and rather cumbersome to use.
I would rather have a function explicitely retrieve objects by ids and another perform a directory search.
Anyway, if you want to debug your function I suggest you drop the class type check and see what happens.