Strpos offset in PHP not working as expected? - php

Question

I've been pulling my hair for hours for this. I'm trying to find all the positions of iframe The first occurrence is successful but not the second one.
Here's my code
$ofAllIFrames = qp( $this->content, 'iframe' );
$iframes = array();
$allIframes = array();
$startTag = 0;
foreach( $ofAllIFrames as $iframe) {
$startCurrentTag = strpos( $this->content, '<iframe>', $startTag );
$endCurrentTag = strpos( $this->content, '</iframe>', $startTag );
$iframes[] = array(
'start' => $startCurrentTag,
'end' => $endCurrentTag
);
$allIframes[] = $iframe;
$startTag = $endCurrentTag;
var_dump($startTag);
ob_flush();
}
return array(
'hasIFrame' => count( $allIframes ) > 0,
'elements' => $iframes
);
And this is my test case
public function test_if_content_has_multiple_iframes() {
$content = 'some content <iframe></iframe> <iframe id="1"></iframe> and another content';
$iframeChecker = new IFrame_Checker( $content );
$params = $iframeChecker->check();
$this->assertTrue( $params['hasIFrame'] );
$this->assertEquals( 13, $params['elements'][0]['start'] );
$this->assertEquals( 21, $params['elements'][0]['end'] );
$this->assertEquals( 31, $params['elements'][1]['start'] );
$this->assertEquals( 46, $params['elements'][1]['end'] );
}
And the test failed for the second iframe
1) Test_IFrame::test_if_content_has_multiple_iframes
Failed asserting that false matches expected 31.

Answer 1

$startCurrentTag = strpos( $this->content, '<iframe>', $startTag );
$endCurrentTag = strpos( $this->content, '</iframe>', $startCurrentTag );
Should work better.
Reason:
$startTag equals $endCurrentTag from the previous loop which refers to the offset at </iframe>.... So this is going to return the same position if you use $endCurrentTag = strpos( $this->content, '</iframe>', $startTag );