Working with trees

When working with tree data structures you often need to craft them in different ways. PHP offers a lot of functions to change the shape of arrays, but often they only go 1 level deep. Trees can count an almost infinite number of levels. Hence we need recursive replacements for our beloved array & string functions.

replaceTree

replaceTree is the tree version of str_replace. It will recursively replace through an array of strings.

<?php
/**
 * Recursive alternative to str_replace that supports replacing keys as well
 * 
 * @param string  $search
 * @param string  $replace
 * @param array   $array
 * @param boolean $keys_too
 * 
 * @return array
 */
function replaceTree($search="", $replace="", $array=false, $keys_too=false)
{ 
    if (!is_array($array)) {
        // Regular replace
        return str_replace($search, $replace, $array);
    }
    
    $newArr = array();
    foreach ($array as $k=>$v) {
        // Replace keys as well?
        $add_key = $k;
        if ($keys_too) {
            $add_key = str_replace($search, $replace, $k);
        }
        
        // Recurse
        $newArr[$add_key] = replaceTree($search, $replace, $v, $keys_too);
    }
    return $newArr;
}
?>

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