Making sure multiple numeric ID input can be allowed in the most flexible way possible

Agaric knows that the best usability would never have people entering numeric IDs into a text field in the first place, but pending fancy remote search and completion techniques, we can at least take a set of numbers without rejecting them for using semicolons instead of commas.

<?php
/**
 * Replace all other separators in a string with spaces and split into arary.
 *
 * Agaric Utility function most practical for numeric IDs, rather than text.
 *
 * @param $string
 *  String value containing one or more simple values, separated by anything.
 * @return
 *  Array of values from the split string.
 */
function biblioreference_au_rationalize_separators($string) {
  // transform all separators into spaces
  // @REVIEW for pubmed ids we could replace all non-numeric with space
  $seps = array(',', ';', ':', '|', '.');
  $pmids = str_replace($seps, ' ', $form_state['values']['biblioreference_pubmed_id']);
  $string = trim(ereg_replace(' +', ' ', $string));
  return explode(' ', $string);
}
?>

Then checking that each of those is an actual integer is another step.

is_int is no good for checking form data, but there are a couple ways:

<?php
if (eregi("^[[:digit:]]+$", $presumed_integer_value) {
  return FALSE;
}
?>

or:

<?php
if (preg_match("/[^0-9]/", $presumed_integer_value)) {
  return FALSE;
}
?>

preg is usually faster, and apparently generally better.

Oh wait. There is a PHP function for checking that something is a straight-up integer, provided that it is given a string value (which forms always will). That function is

<?php
  ctype_digit($presumed_integer_value)
?>

http://us2.php.net/manual/en/function.ctype-digit.php

Resolution