Call a function without its parameters - php

Question

Below are the functions that am using to make reusable pagination. If you see the code below, theirs a function
generate_pages()
which is taking parameters from function
paged_controls()
But I would like to call the function generate_pages() without passing any parameters on body.php.
This is the error message am getting on body.php when calling function
generate_pages()
Warning: Missing argument 1 for generate_pages(), called in
E:\admin\snippets\body.php on line 11 and defined in
E:\admin\cores\pages.php on line 12
Notice: Undefined variable: limit in E:\xampp\htdocs\projects\hoplate\admin\cores\pages.php on line 16
Is that possible?
pages.php
<?php
function page_count(){
global $db;
$sql = "SELECT COUNT(pages_id) FROM pages";
$query = $db->SELECT($sql);
$rows = $db->FETCH_ROW();
foreach($rows as $row){
return $row[0];
}
}
function generate_pages($limit){
/* Run actual query now to get the records from database */
global $db;
$sql = "SELECT * FROM pages " . $limit;
$query = $db->SELECT($sql);
return $rows = $db->FETCH_OBJECT();
}
function paged_controls($page_rows = 1){
global $db;
/* Call the function page_count to get the total page count */
$row_count = page_count();
/* We use the ceil function to round the number to whole number */
$last = ceil($row_count / $page_rows);
/* Make sure that the last page cannot be less then 1 */
if($last < 1){
$last = 1;
}
/* Est. the page number variables */
$pagenum = 1;
/* Set the pagenum variables from URL else set it to 1*/
if(isset($_GET["paged"])){
$pagenum = preg_replace('#[^0-9]#', '', $_GET["paged"]);
}
/* Make sure page number canoot be less then 1 */
if($pagenum < 1){
$pagenum = 1;
} else if($pagenum > $last){
$pagenum = $last;
}
/* Set the range of query to be excuted depend on our variables values set*/
$limit = 'LIMIT '.($pagenum - 1) * $page_rows . ','. $page_rows;
generate_pages($limit);
$paged_controls = "";
/* Only if theirs more then 1 page of results */
if($last != 1){
if($pagenum > 1){
$previous = $pagenum - 1;
$paged_controls .= 'Previous ';
/* Renders the left paged numbers */
for($i = $pagenum - 4; $i < $pagenum; $i++){
if($i > 0){
$paged_controls .= ''.$i.' ';
}
}
}
/* Render the current page the user is at */
$paged_controls .= ''.$pagenum.' ';
/* Renders the right paged numbers */
for($i = $pagenum + 1; $i <= $last; $i++){
$paged_controls .= ''.$i.' ';
if($i >= $pagenum + 4){
break;
}
}
if($pagenum != $last){
$next = $pagenum + 1;
$paged_controls .= 'Next ';
}
return $paged_controls;
}
}
?>
body.php
<?php
$pages = generate_pages();
foreach($pages as $page){
echo $pages_id = $page->pages_id . "<br/>";
}
?>

Answer 1

Only way I would see this working is adding a check.
function generate_pages($limit = null){
/* Run actual query now to get the records from database */
$gloab $db;
$sql = "SELECT * FROM pages " . isset($limit) ? "LIMIT $limit" : "";
$query = $db->SELECT($sql);
return $rows = $db->FETCH_OBJECT();
}
So now it could be run one of two ways
generate_pages();
or:
generate_pages(10);

Answer 2

Compare both of your function headers:
function generate_pages($limit)
function paged_controls($page_rows = 1)
PHP offers you to specify default arguments, just like C++ (you have to scroll down a bit to see the section).
Your paged_controls-function already does this and it is a great way of achieving what you want without editing the business logic within the function.
A default argument kicks in whenever you call a function without any parameters.
So, if you edit
function generate_pages($limit)
to (for example)
function generate_pages($limit = 'LIMIT 0,18446744073709551615')
and call the function via generate_pages(), PHP will automatically assume $limit = 'LIMIT 0,18446744073709551615'.
In this specific case, calling generate_pages without a parameter will retrieve all entries in the table you select from, as we tell the database to give us 18446744073709551615 entries from the beginning.
See the MYSQL manual on select/limit.