call to a member function children() on a non-object

Door Daniel van Seggelen op 22-08-2018 15:07

2.107 views

Als ik onderstaande code run, dan krijg ik de foutmelding in de titel.
Ik probeer dat te omzeilen, maar dat gaat niet. Weet iemand wat ik verkeerd doe?



foreach($detail_html->find('div[class=row grid]') as $gg) 
							{							
						
								$oppervlakte =  $gg->children(0)->next_sibling()->next_sibling()->children(0)->next_sibling()->children(0)->children(0)->children(0)->next_sibling();
								$house_type = $gg->children(0)->next_sibling()->children(0)->next_sibling()->children(0)->children(0)->children(0)->next_sibling();



    $isObject = false;
    if ( false !== $gg->children(0)->next_sibling()->next_sibling()->next_sibling()->children(0)->next_sibling()->children(0)->children(0)->children(0)->next_sibling()  ) {
        $isObject = true;
		$aantal = $gg->children(0)->next_sibling()->next_sibling()->next_sibling()->children(0)->next_sibling()->children(0)->children(0)->children(0)->next_sibling();
    }
    if($isObject){
	$arr_test[] = array('rooms',trim(strip_tags( $aantal)));	
	}

Thomas van den Heuvel

23-08-2018 16:53

Wat @Ward zei, schrijf een soort van trace functie die je ook informatie teruggeeft over waar het misgaat, zoiets dus:

<?php
// include simple_html_dom hier ergens
// ...

ob_start();
?><h2>random header</h2>
<p>introducution</p>
<div id="tree">
    <ul>
        <li>1<ul>
            <li>1.1<ul>
                <li>1.1.1<ul>
                    <li>1.1.1.1</li>
                </ul></li>
                <li>1.1.2</li>
            </ul></li>
        </ul></li>
        <li>2</li>
        <li>3<ul>
            <li>3.1</li>
            <li>3.2<ul>
                <li>3.2.1</li>
                <li>3.2.2</li>
            </ul></li>
        </ul></li>
    </ul>
</div><?php
$input = ob_get_clean();

$html = str_get_html($input);
$tree = $html->find('div[id=tree] ul', 0); // returns an array of simple_html_dom_node's

$test = $tree->children(0)->children(0)->children(0)->children(0)->children(0)->next_sibling();
echo $test->innertext().'<hr>'; // 1.1.2

$trace = array(
    array('c', 0),  // children, index 0
    array('c', 0),  // children, index 0
    array('c', 0),  // children, index 0
    array('c', 0),  // children, index 0
    array('c', 0),  // children, index 0
    array('n'),     // next sibling
);

function domTrace($in, $trace) {
    $step = 0;
    foreach ($trace as $action) {
        switch ($action[0]) {
            case 'c': // children
                if (method_exists($in, 'children')) {
                    if (isset($action[1])) { // was an index provided?
                        $in = $in->children($action[1]);
                    } else {
                        $in = $in->children();
                    }
                    if ($in === NULL) {
                        throw new Exception('children not found in step '.$step);
                    }
                } else {
                    throw new Exception('method children does not exist in step'.$step);
                }
            break;
            case 'n': // next_sibling
                $in = $in->next_sibling();
                if ($in === NULL) {
                    throw new Exception('sibling not found in step '.$step);
                }
            break;
            default: throw new Exception('unknown op in step '.$step);
        }
        $step++;
    }
    return $in;
}

try {
    $test = $tree;
    $test = domTrace($test, $trace);
    echo $test->innertext(); // 1.1.2
} catch (Exception $e) {
    echo $e->getMessage();
}
?>[end]

En als je de foutmeldingen stilzwijgend wil afhandelen zou je false kunnen retourneren in plaats van het throwen van een Exception.

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