这个html dom php代码有什么问题？

Question

I'm trying to do a code that will print the contents of all the elements with itemprop="price" from some link but it don't work, I can't figure out why, this is the code:

<?php
error_reporting(0);
ini_set('display_errors', 0);
$doc      = new DOMDocument();
$allscan  = array(
    'http://www.mobile54.co.il/30786',
    'http://www.mobile54.co.il/35873',
    'http://www.mobile54.co.il/34722'
);
$alllinks = array();
$html     = file_get_contents($allscan[0]);
$doc->loadHTML($html);
$href = $doc->getElementsByTagName('a');
for ($j = 0; $j < count($allscan); $j++) {
    $html = file_get_contents($allscan[$j]);
    $doc->loadHTML($html);
    $href = $doc->getElementsByTagName('a');
    for ($i = 0; $i < $href->length; $i++) {
        $link = $href->item($i)->getAttribute("href");
        $lin  = preg_replace('/\s+/', '', 'http://www.mobile54.co.il' . $link . "<br />");
        if (strpos($link, 'items/') && !strpos($link, '#techDetailsAName')) {
            if (!in_array($lin, $alllinks)) {
                $alllinks[] = $lin;
            }
        }
    }
}

for ($i = 0; $i < count($alllinks); $i++) {
    echo $alllinks[$i];
}
for ($i = 0; $i < count($alllinks); $i++) {
    $lin  = "$alllinks[$i]";
    $html = file_get_contents($lin);
    $doc->loadHTML('<?xml encoding="UTF-8"?>' . $html);
    $span = $doc->getElementsByTagName('span');
    for ($j = 0; $j < $span->length; $j++) {
        $attr = $span->item($j)->getAttribute('itemprop');
        if ($attr == "price") {
            echo $span->item($j)->textContent . "<br />";
        }
    }
}


?> 

when I paste "someurl" insted of $lin it work but the other way doesn't. I've tried to do $html = file_get_contents($alllinks[$i]); but it didn't work, I don't know why.

Answer 1

I think your problem is probably that you appended a <br /> to the end of your URL for some reason. But, there are a lot of opportunities to improve your code with use of XPath. (Note also that you can just pass a URL directly to the DomDocument object.)

First we pull all the <a> elements with matching attribute values. We get the URLs and then search them for elements with the exactly matching itemprop attribute, and get the text content of them.

<?php
$url = "http://www.mobile54.co.il/30786";
$prices = [];
$hrefs = [];
$combined = [];

$dom = new DomDocument;
libxml_use_internal_errors(true);
$dom->loadHtmlFile($url);
$xpath = new DomXPath($dom);
// get <a> elements with href containing items/ but not #techDetailsAName
$nodes = $xpath->query("//a[contains(@href, 'items/') and not(contains(@href, '#techDetailsAName'))]/@href");
foreach ($nodes as $node) {
    $hrefs[] = trim($node->value);
}

// now you have a list of URLs
foreach ($hrefs as $k=>&$href) {
    $href = "http://www.mobile54.co.il$href";
    $dom->loadHtmlFile($href);
    $xpath = new DomXPath($dom);
    // get any element with itemprop of price
    $nodes = $xpath->query("//*[@itemprop='price']");
    $prices[$k] = $nodes->item(0)->textContent;
}

// now you have $urls and $prices, combine them:
foreach ($hrefs as $k=>$v) {
    $combined[$k] = [$hrefs[$k], $prices[$k]];
}
print_r($combined);