get_attachment_id() only get id of first attached image after post update

Question

i use the code explained here to get id of attached images to a post in a custom post type from $value that contains url of image (images already uploaded & exist in Media Library). the post contains some data and images that users submitted & uploaded via a form. when i publish post for the first time from quick edit menu, that function works perfectly and retrieve id of all attached images then i can use update_field command and add images to acf image field with array of images attachment ids.the problem appears when i update/publish post from Edit Page (not quick edit menu). in this case that function only return id of first attached image and return 0 for other attached images. then acf image field only show that image only.

other Description that maybe useful:

i have a custom field named 'pics' that contains url of uploaded images via form and its value is something like this:

pic03.png
http://insell.ir/wp-content/uploads/fsqm-files/pic03.png

pic02.png
http://insell.ir/wp-content/uploads/fsqm-files/pic02.png

pic01.jpg
http://insell.ir/wp-content/uploads/fsqm-files/pic01.jpg

i use this code in my template to extract urls from 'pics' custom field and save them in $attach_ids as array and finally update acf image field with that:

<?php

$img = get_post_meta( get_the_ID(), 'pics', true);
$imgList = explode("\n", $img);
$attach_ids = array();
foreach ( $imgList as &$value ) {
    if ( strpos( $value, 'http:' ) !== false ) {
        $attachment_id = get_attachment_id( $value );
        array_push($attach_ids, $attachment_id);
    }
}
// print_r ($attach_ids);
$images = update_field( 'slider_portfolio', $attach_ids, get_the_ID() ); 
$images = get_field('slider_portfolio');

?>

in case 1 (publish post via quick edit), print_r ($attach_ids); show correct output that contains all images id:

Array ( [0] => 1276 [1] => 1278 [2] => 1277 )

in case 2 (publish/update post via edit page), print_r ($attach_ids); show this output:

Array ( [0] => 0 [1] => 0 [2] => 1277 )

Any help would be really appreciated. thank you very much.

Answer 1

after 3 days i found the problem was because of an space in end of urls in $imgList array (Except last url) !!! so i added trim for each url ($value) and solved problem ...

<?php

$img = get_post_meta( get_the_ID(), 'pics', true);
$imgList = explode("\n", $img);
$attach_ids = array();

foreach ( $imgList as &$value ) {
    if ( strpos( $value, 'http:' ) !== false ) {
        $value = trim($value);
        $attachment_id = get_attachment_id( $value );
        array_push($attach_ids, $attachment_id);
    }
}

$images = update_field( 'slider_portfolio', $attach_ids, get_the_ID() ); 
$images = get_field('slider_portfolio');

?>

there isn't any problem with get_attachment_id() function. it's perfect !