drupal_expandArguments.php

<?php
protected function expandArguments(&$query, &$args) {
    $modified = FALSE;
    
    // If the placeholder value to insert is an array, assume that we need
    // to expand it out into a comma-delimited set of placeholders.
    foreach (array_filter($args, 'is_array') as $key => $data) {
        $new_keys = array();
        foreach ($data as $i => $value) {
            // This assumes that there are no other placeholders that use the same
            // name.  For example, if the array placeholder is defined as :example
            // and there is already an :example_2 placeholder, this will generate
            // a duplicate key.  We do not account for that as the calling code
            // is already broken if that happens.
            $new_keys[$key . '_' . $i] = $value;
        }
        
        // Update the query with the new placeholders.
        // preg_replace is necessary to ensure the replacement does not affect
        // placeholders that start with the same exact text. For example, if the
        // query contains the placeholders :foo and :foobar, and :foo has an
        // array of values, using str_replace would affect both placeholders,
        // but using the following preg_replace would only affect :foo because
        // it is followed by a non-word character.
        $query = preg_replace('#' . $key . '\b#', implode(', ', array_keys($new_keys)), $query);
        
        // Update the args array with the new placeholders.
        unset($args[$key]);
        $args += $new_keys;
        
        $modified = TRUE;
    }
    
    return $modified;
}