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Salathe · 01-01-2010, 07:13 PM

I would like to introduce another approach to your problem, one which you're probably not aware of so would've have considered yet. To so do, you will have to think a little out of the box and if you're new to using classes/objects then things might seem a bit weird.

Another concept in there is filtering user input using the filter extension. It just makes the common task of filtering input a bit easier by allowing us to quickly validate the input type (in this case, integers only) and optionally limit the values to a specific range (1…1000) or specify a default value if none is present (1).

PHP Code:


			
// Open our flat file database for reading

$lines = new SplFileObject('flat-file-data.txt', 'r');



// Grab the user-requested page number from $_GET (with max/min/default limits)

$page    = filter_input(INPUT_GET, 'page', FILTER_VALIDATE_INT, array(

    'options' => array(

        'default'   => 1,

        'max_range' => 1000,

        'min_range' => 1

    )

));



// Ten lines per page

$perpage = 10;



// How many lines into the file should we start at

$offset  = ($page - 1) * $perpage;



// Limit the lines to the start point and number of lines per page

$page    = new LimitIterator($lines, $offset, $perpage);



// If this page does not exist (offset is too big), show first page instead

if (iterator_count($page) === 0) {

    $page = new LimitIterator($lines, 0, $perpage);

}



// Loop over this page of lines, displaying each one

foreach ($page as $line) {

    echo $line;

}

P.S. The LimitIterator isn't documented beyond the basic method and arguments lists. If you have any questions, do ask me... they might be useful for when I get around to writing the documentation for that class.

01-01-2010, 07:13 PM	#4 (permalink)
Salathe Moderateur Join Date: Apr 2007 Posts: 1,393 Thanks: 5	I would like to introduce another approach to your problem, one which you're probably not aware of so would've have considered yet. To so do, you will have to think a little out of the box and if you're new to using classes/objects then things might seem a bit weird. Another concept in there is filtering user input using the filter extension. It just makes the common task of filtering input a bit easier by allowing us to quickly validate the input type (in this case, integers only) and optionally limit the values to a specific range (1…1000) or specify a default value if none is present (1). PHP Code: // Open our flat file database for reading $lines = new SplFileObject('flat-file-data.txt', 'r'); // Grab the user-requested page number from $_GET (with max/min/default limits) $page = filter_input(INPUT_GET, 'page', FILTER_VALIDATE_INT, array( 'options' => array( 'default' => 1, 'max_range' => 1000, 'min_range' => 1 ) )); // Ten lines per page $perpage = 10; // How many lines into the file should we start at $offset = ($page - 1) * $perpage; // Limit the lines to the start point and number of lines per page $page = new LimitIterator($lines, $offset, $perpage); // If this page does not exist (offset is too big), show first page instead if (iterator_count($page) === 0) { $page = new LimitIterator($lines, 0, $perpage); } // Loop over this page of lines, displaying each one foreach ($page as $line) { echo $line; } P.S. The LimitIterator isn't documented beyond the basic method and arguments lists. If you have any questions, do ask me... they might be useful for when I get around to writing the documentation for that class.