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Foreach and where combined in PHP


ementalis

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Is it posible to make a foreach loop and use where something equals somemething condition in PHP?
 
E.g. I have a code like:
 

 

    <?php foreach($parents as $parent) : ?>
      echo $parent->title;
    <?php endforeach; ?>
 

 

 
And I would like to have something like:
 

 

    <?php foreach($parents as $parent, where $parent->type = 'submenu1') : ?>
      echo $parent->title;
    <?php endforeach; ?>
 

 

 
So, it will filter stuff on the fly.
 
The reason behind it is that I can do only one mysql query and grab all submenus stuff and then in php code loop just one object instead of e.g. 20 or more.
 
how to do such thing and implement where filter in foreach loop?
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If the original parents array is the result of a SQL query, do the filtering in the query

I cannot do 20 or 50 queries and send them to view. thats crazy ;D I can of ourse do the if condition inside foreach loop but I prefer some more elegant and playfuly-clever solution

Edited by ementalis
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I can of ourse do the if condition inside foreach loop but I prefer some more elegant and playfuly-clever solution

<?php

class ConditionalIterator implements Iterator {
	private $mList;
	private $mKeys;
	private $mKeyIdx;

	private $mFieldToCheck;
	private $mFieldValue;

	public function __construct($list, $field, $value){
		$this->mList = $list;
		$this->mKeys = array_keys($list);

		$this->mFieldToCheck = $field;
		$this->mFieldValue = $value;

		$this->rewind();
	}
	
	private function getNextMatchingKeyIndex($s){
		for (; $s<count($this->mKeys); $s++){
			$k = $this->mKeys[$s];
			$v = $this->mList[$k];

			if (is_array($v) && isset($v[$this->mFieldToCheck])){
				if ($v[$this->mFieldToCheck] == $this->mFieldValue){
					return $s;
				}
			}
			else if (is_object($v) && isset($v->{$this->mFieldToCheck})){
				if ($v->{$this->mFieldToCheck} == $this->mFieldValue){
					return $s;
				}
			}
		}

		return false;
	}

	public function rewind(){
		$this->mKeyIdx = $this->getNextMatchingKeyIndex(0);
	}

	public function current(){
		$key = $this->key();
		return $this->mList[$key];
	}

	public function key(){
		return $this->mKeys[$this->mKeyIdx];
	}

	public function next(){
		$this->mKeyIdx = $this->getNextMatchingKeyIndex($this->mKeyIdx+1);
	}

	public function valid(){
		return $this->mKeyIdx !== false;
	}
}

$a = new stdclass();
$a->type = 'a';
$a->name = 'one';
$b = new stdclass();
$b->type = 'b';
$b->name = 'two';
$c = new stdclass();
$c->type = 'c';
$c->name = 'three';

$ap = new stdclass();
$ap->type = 'a';
$ap->name = 'four';
$bp = new stdclass();
$bp->type = 'b';
$bp->name = 'five';
$cp = new stdclass();
$cp->type = 'c';
$cp->name = 'six';

$list = array($a, $b, $c, $ap, $bp, $cp);

foreach (new ConditionalIterator($list, 'type', 'b') as $k=>$v){
	var_dump($k, $v);
}
echo 'Done!';


 

There ya go. Complex, hard to understand, and in complete violation of the KISS principal, just like you ordered.

Edited by kicken
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