[Done v1.5] Mandatory text attribute -problem

Whilst playing around trying to get something else working I came across this 'anomally'

I created option-name 'Adult', type 'Text',width '5', max '1' - to display a box 5 characters wide and only permit a single character entry.

I added this attribute to a product and selected 'Attribute reqired for text' - because the buyer must enter a character (actually I want numeric 0-9, but I dont believe there is a way to validate the string entered)

When I then 'buy' the product if I don't enter text I get a warning - exactly as required

BUT:ohmy:

If I enter the character '0' (numeric zero) I still get the same warning message 'user Input required' - is this a bug??:(

AM I correct in thinking there is no way to define a default value for the string, instead of an empty string??

I found in functions_lookups.php in the zen_get_attributes_valid function.

// text required validation
    if (preg_match('/^txt_/', $option)) {
      $check_attributes = $db->Execute("select attributes_display_only, attributes_required from " . TABLE_PRODUCTS_ATTRIBUTES . " where products_id='" . (int)$product_id . "' and options_id='" . (int)preg_replace('/txt_/', '', $option) . "' and options_values_id='0'");
// text cannot be blank
      if ($check_attributes->fields['attributes_required'] == '1' and empty($value)) {
        $check_valid = false;
      }
    }

This appears to use the PHP empty() function to check a string

I found http://www.zachstronaut.com/posts/2009/02/09/careful-with-php-empty.html which states

2. Do Not Use empty() with Strings

In many cases, empty() cannot be used with string variables for the simple fact that empty() returns true if your variable is set the the string value '0'. If the string character '0' is a possibly valid value for your string variable — if all non-zero-length strings are valid — you cannot use empty(). This is even more dangerous if you are using empty() to check if a string variable is defined. Also worth mentioning, empty() returns false for a string value that is nothing but a single space (or any number of spaces really).

Which thus suggests that this attribute checking code has a problem - which I dont (yet) know how to fix.

How about changing

// text cannot be blank
      if ($check_attributes->fields['attributes_required'] == '1' and empty($value)) {
        $check_valid = false;

to

// text cannot be blank
      if ($check_attributes->fields['attributes_required'] == '1' and empty($value) and !is_numeric($value)) {
        $check_valid = false;

see the first user contribution on http://php.net/manual/en/function.empty.php

tried it on my local copy - corrected the specific problem - but I dont know if there are any deeper ramifications

Take a look at this other thread
http://www.zen-cart.com/forum/showthread.php?p=1043112#post1043112

With a text attribute defined as mandatory and max length 1 character entering a single '0' character is reported as still being empty

using the PHP function empty() on string variables is known to report certain strings as empty which are not infact empty.

Moderator's note: Original thread merged here.

Have you reviewed this post:
http://www.zen-cart.com/forum/showthread.php?p=1056323#post1056323

Some mods clobber the database fields which enforce the required text attribute logic.

tsrplatelayer:

How about changing

// text cannot be blank
if ($check_attributes->fields['attributes_required'] == '1' and empty($value)) {
$check_valid = false;

> to
> ```
// text cannot be blank
      if ($check_attributes->fields['attributes_required'] == '1' and empty($value) and !is_numeric($value)) {
        $check_valid = false;

see the first user contribution on http://php.net/manual/en/function.empty.php

This should fix the issue where the input on a text required attribute is 0 (the number zero) as empty($value) will evaluate as empty if that value is 0 (the number zero) ...