defining product listing default sort order in default_filter.php, faulty iteration

[gjh42]

More study about PHP "break" shows that only operates in for/while/switch type structures, not if() structures, but it is not unequivocally clear whether a break inside an if will operate on the for outside it.
But yet, it moves...

[RodG]

More study about PHP "break" shows that only operates in for/while/switch type structures, not if() structures, but it is not unequivocally clear whether a break inside an if will operate on the for outside it.
But yet, it moves...

How would you place a 'break' inside an 'if' anyway?

if ($a == 1) {
dosomething;
break ;
} else {
dosomethingelse;
break ;
}

Clearly, there is nothing to break out of here.

if ($a == 1) {
dosomething;
break ;
dosometyhingelse ;
}

That may work, sort of, but even if it did, it is clearly a pointless thing to do, the 'dosometyhingelse' will never be invoked.

What other possible scenarios are there?
-------------------------------------
for ($i=0, $n=sizeof($column_list); $i<$n; $i++) {
if (isset($column_list[$i]) && $column_list[$i] == 'PRODUCT_LIST_NAME') {
$_GET['sort'] = $i+1 . 'a';
$listing_sql .= " order by p.products_sort_order, pd.products_name";
break;
} else {
$listing_sql .= " order by p.products_sort_order, pd.products_name";
break;
}
}
-------------------------------------

Just for grins, I've stepped through this code and torvista is correct, this code only checks the first column defined, not all of them.

Cheers
Rod

[Ajeh]

That code only runs if the setting is:

1 Blank

2 Invalid choice

to set up a valid order by for:

          $listing_sql .= " order by p.products_sort_order, pd.products_name";

The IF allows for an invalid setting to be used on the ELSE portion that may be wanted that goes beyond the normal settings such as if you wanted a method for products_date_added and set to 5a (an invalid choice if only 4 columns are defined) by using:

        } else {
echo 'ELSE ' . '<br>';        	
// sort by products_sort_order when PRODUCT_LISTING_DEFAULT_SORT_ORDER is left blank
// for reverse, descending order use:
//       $listing_sql .= " order by p.products_sort_order desc, pd.products_name";
//          $listing_sql .= " order by p.products_sort_order, pd.products_name";
          $listing_sql .= " order by p.products_date_added, pd.products_name";
          break;
        }

While not eloquent ... it makes the change easier to change on the default display order for the listing ...

[DrByte]

To summarize ...

1) Question
Why is this limited to three when as far as I can see, the code deals only with two characters eg 2a?

Correct. At the present time the code only deals with two characters.
But, harmless.

2a)
$_GET['sort'] contains characters not 1-8 or a or d ( Question: Why are column numbers 1-8 allowed when there are only 7 options?)

Actually, it should probably be expanded to allow for 0-thru-9.

2b) Bug? : However the else clause has a break too, so this loop will only ever execute once and never identify the Product Name column unless it is the first column.

Ya, probably a bug.
Yet, it appears Ajeh has posted about a curious beneficial side-effect which can utilize this for positive results.

3) Question about "20a"
I cannot find where the second digit “0” is taken any account of…is this a typo and should be “2a”?

Indeed, in the case of "20a", the "0a" has no effect, and is essentially ignored, since it is neither "a" nor "d", and thus the current code uses other defaults.
Changing it to "2a" doesn't necessarily accomplish the desired end result either, depending what your desired end result is.

[torvista]

ok, thanks for the confirmations.
This all came about while trying to understand the default sorting mechanisms...