how can match some string from content in array (Right to Left)? - php

Question

I have music chord and lyrics like this :
<p>[Fm]   [Gm]    [Dm]</p>
<p>لورم ایپسوم ، لورم ایپسوم</p>
<p>[A] [Asus4] [Bb]</p>
<p>لورم ایپسوم ، لورم ایپسوم</p>
the "p" tags generated by wordpress editor for each line.
I collect the Chord with brackets by using :
preg_match_all("/\[[^\]]*\]/", $content , $matches);
And result is :
[0] => [Fm]
[1] => [Gm]
[2] => [Dm]
[3] => [A]
[4] => [Asus4]
[5] => [Bb]
but I need to collect the chords from right to left and my array should be like this one :
[0] => [Dm]
[1] => [Gm]
[2] => [Fm]
[3] => [Bb]
[4] => [Asus4]
[5] => [A]
Thanks.

Answer 1

You could try to capture a single line first by matching to: (\[[^\]]*\])+(\<\\p\>){1}
You can then take a matched string and match it against your expression: /\[[^\]]*\]/.
If you take these secondary matches and put them in a 2d array you'll now have a object with this structure:
[0] => [Fm, Gm, Dm]
[1] => [A, Asus4, Bd]
Some (pseudo)code:
$outputarr = [];
preg_match_all("/(\[[^\]]*\])+(\<\\p\>){1}/", $content , $matches);
foreach ($matches as &$value) {
$internalarray = [];
preg_match_all("//\[[^\]]*\]/", $value , $matches2);
foreach ($matches2 as &$value2) {
array_push($internalarray, $value2);
}
array_push($outputarr, $internalarray);
}
You can now call the array_reverse function on elements [0] and [1] to get:
[0] => [Dm, Gm, Fm]
[1] => [Bd, Asus4, A]
And you can finally go from that to a single array by doing this:
$arr = [];
foreach ($outputarr as &$value) {
$arr = array_merge($arr, $value);
}
This should give your wanted inside variable $arr:
[0] => [Dm]
[1] => [Gm]
[2] => [Fm]
[3] => [Bb]
[4] => [Asus4]
[5] => [A]
ps: I haven't taken the whitespace characters into account and ((\[[^\]]*\])|\s)+(\<\\p\>){1} could be the better one. Furthermore this code could be improved by using array_merge and as such bypassing manual array_push

Answer 2

$content = "<p>[Fm] [Gm] [Dm]</p>
<p>لورم ایپسوم ، لورم ایپسوم</p>
<p>[A] [Asus4] [Bb]</p>
<p>لورم ایپسوم ، لورم ایپسوم</p>";
preg_match_all("/<p>.*<\/p>/", $content , $nodes);
$final = [];
foreach ($nodes[0] as $node ) {
if(!empty($node)) {
preg_match_all("/\[[^\]]*\]/", $node , $matches);
if(!empty($matches[0])) {
$final = array_merge($final, array_reverse($matches[0]));
}
}
}
print_r($final);