Query Defaults

Choose a safe default for a query value.

query-defaults Web handlers often read optional query data. Static lessons can model the query value with local scalar data instead of reading a real request.

                            page
                            page = 1 (default)page = 2page = 5
                        

                            query_defaults.php
                        
Replay: real traced execution (multi-file project)

                            <?php
$page = 1;
$pageSize = 10;
$offset = ($page - 1) * $pageSize;

echo "page=" . $page . "\n";
echo "offset=" . $offset . "\n";
<?php
$page = 2;
$pageSize = 10;
$offset = ($page - 1) * $pageSize;

echo "page=" . $page . "\n";
echo "offset=" . $offset . "\n";
<?php
$page = 5;
$pageSize = 10;
$offset = ($page - 1) * $pageSize;

echo "page=" . $page . "\n";
echo "offset=" . $offset . "\n";

                        
1$page ← 1, $pageSize ← 10, $offset ← 01<?php2$page→ 1 = 1; //@page=2, 53$pageSize→ 10 = 10;4$offset→ 0 = ($page1 - 1) * $pageSize10;56echo "page=" . $page1 . "\n";7echo "offset=" . $offset0 . "\n";⋯outputpage=1
offset=0
1$page ← 2, $pageSize ← 10, $offset ← 101<?php2$page→ 2 = 2;3$pageSize→ 10 = 10;4$offset→ 10 = ($page2 - 1) * $pageSize10;56echo "page=" . $page2 . "\n";7echo "offset=" . $offset10 . "\n";⋯outputpage=2
offset=10
1$page ← 5, $pageSize ← 10, $offset ← 401<?php2$page→ 5 = 5;3$pageSize→ 10 = 10;4$offset→ 40 = ($page5 - 1) * $pageSize10;56echo "page=" . $page5 . "\n";7echo "offset=" . $offset40 . "\n";⋯outputpage=5
offset=40