Online PHP editor | output for f8kAs

<?php function renderBlock(array $m) { $callable = "build$m[1]"; return function_exists($callable) ? $callable($m[2] ?? '') : $m[0]; } function buildPiechart(string $payloadString) { $values = [ 'angle' => 0, 'colorset' => 'red', 'stroke' => 1, 'value' => 1 ]; $rules = [ 'angle' => '/\d+/', 'colorset' => '/reds|yellows|blues/i', 'stroke' => '/\d+/', 'value' => '/\d+/', ]; $attributes = preg_split( '/\h+/u', $payloadString, 0, PREG_SPLIT_NO_EMPTY ); foreach ($attributes as $pair) { [$key, $value] = explode(':', $pair, 2); if ( key_exists($key, $values) && preg_match($rules[$key], $value, $m) ) { $values[$key] = $m[0]; } } return sprintf( '<pie a="%s" c="%s" s="%s" v="%s">', ...array_values($values) ); } $text = 'here is a block to be replaced [block:piechart value:25 angle:0] [block] and [block:notcoded attr:val] another one [block:piechart colorset:reds value:20]'; echo preg_replace_callback( '/\[block:([a-z]+)\h*([^\]\r\n]*)\]/u', 'renderBlock', $text );