Online PHP editor | output for XENqu

<?php const ERRMODE_EMPTY = 1; const ERRMODE_LITERAL = 2; const ERRMODE_EXCEPTION = 3; function render_template($template, array $variables, $escapeChar = '@', $errMode = ERRMODE_EXCEPTION) { $esc = preg_quote($escapeChar); $expr = "/ $esc$esc(?=$esc*+{) | $esc{ | {(\w+)} /x"; $callback = function($match) use($variables, $escapeChar, $errMode) { switch ($match[0]) { case $escapeChar . $escapeChar: return $escapeChar; case $escapeChar . '{': return '{'; default: if ($errMode === ERRMODE_EMPTY) { return ''; } else if ($errMode === ERRMODE_LITERAL) { return $match[0]; } else if ($errMode === ERRMODE_EXCEPTION) { throw new \Exception('Unknown placeholder: ' . $match[1]); } else { return $errMode; } } }; return preg_replace_callback($expr, $callback, $template); } $template = <<<'TPL' HELLO {name} How are you doing {when} Feeling @{ok}? TPL; $data = [ 'name' => 'WORLD', 'when' => 'yesterday', ] echo render_template($template, $data);