POST variable

[mcquam]

I have a dropdown list that POSTS to itself and shows a table of paginated links. I can get the first page ok and the URL is correct but no subsequent pages of links. So, for example, when I click on the "next" link I get nothing but the dropdown. What am I doing wrong?

This is the form:

echo '<div align="left">
<form action="index.php?p=view_recipes" method="POST">
<select name="type">
<option value="NULL">Choose a category:</option>
';

	// Retrieve and display the available categories.
$catquery = 'SELECT * FROM categories ORDER BY category ASC';
$catresult = mysql_query ($catquery);
while ($row = mysql_fetch_array ($catresult, MYSQL_NUM)) {
	echo "<option value=\"$row[0]\">$row[1]</option>";
}	
	
// Complete the form.
echo '</select>
<input type="submit" name="submit" value="submit">
<input type="hidden" name="submitted" value="TRUE">
</form>

PHP 5.2.9
MySQL 5.0.81-community

 

[feherke]

Hi
[ul]
[li]Where in your code is the pagination ?[/li]
[li]Where in your code are generated links ?[/li]
[li]Where is the "next" link ?[/li]
[/ul]


Feherke.

http://rootshell.be/~feherke/

 

[mcquam]

Pagination is just above the form in the code
Generated links are above that
Next link is immediately above the form.

Here is the entire code:

<?php
// Redirect if page was accessed directly
if(!defined('BASE_URL')) {
	//Need the base url, defined in the config file
	require_once ('./config/config.inc.php');
	
	//Redirect to the index page
	$url = BASE_URL . 'index.php?p=view_recipes';
header ("Location: $url");
exit;
}

// This page displays the recipes from the database.

require_once (DB_REC);
$display = 5; //set number of records per page
	
if (isset($_POST['submitted'])) { // Handle the form.
// Retrieve the recipes for a particular category, if selected.
// Make sure the type is an integer.
if (isset($_POST['type'])) {
	$type = (int) $_POST['type'];
} else {
	$type = 0;
}

if (isset($_POST['np'])) {  // already been determined
	
	$num_pages = $_POST['np'];

} else {  // need to determine
	
	// count the number of records
	$cntquery = "SELECT COUNT(*) FROM recipes, category_assoc 
	WHERE recipes.recipe_id = category_assoc.recipe_id AND category_assoc.category_id = $type";
	$cntresult = mysql_query ($cntquery);
	$rowcnt = mysql_fetch_array ($cntresult, MYSQL_NUM);
	$num_records = $rowcnt[0];
	
	// calculate number of pages
	if($num_records > $display) { // more than 1 page
		$num_pages = ceil($num_records/$display);
	} else {
			$num_pages = 1;
	}
} // end of np if

//mysql_free_result ($cntresult); //  free up resources
	
	if(isset($_POST['s'])) {
		$start = $_POST['s'];
		} else {
			$start = 0;
	}
	
if ($type > 0) {

	// Get the current category name.
	$cnquery = "SELECT category FROM categories WHERE category_id=$type";
	$cnresult = mysql_query ($cnquery);
	list ($category) = mysql_fetch_array ($cnresult, MYSQL_NUM);
	//echo mysql_error();
	"<div align=\"left\"><b>$category recipes</b>";

//mysql_free_result ($cnresult); //  free up resources
	
	// Query the database.
	$mainquery = "SELECT recipes.recipe_id, title, description, method, submitter FROM recipes, category_assoc 
	WHERE recipes.recipe_id = category_assoc.recipe_id AND category_assoc.category_id = $type ORDER BY title ASC LIMIT $start, $display";
	$mainresult = mysql_query ($mainquery) or die(mysql_error());
	

	// table header
	
	echo '<table class="lists">
		<tr>
		<td align="left" width="140px"><font size="+1">Title</font></td>
		<td align="left" width="360px"><font size="+1">Description</font></td>
		<td align="left" width="120px"><font size="+1">Submitted by</font></td>
		</tr>';
	
	$bg = '#eeeeee'; //set background colour

	// Display all the recipes.
	while ($row = mysql_fetch_array ($mainresult, MYSQL_ASSOC)) {

		// Display each record.
			$bg = ($bg=='#eeeeee' ? '#ffffff' : '#eeeeee'); //switch the background colour
				
		echo '<tr bgcolor="' . $bg . '">
			<td align="left"><a href="index.php?p=view_a_recipe&rid=' . $row['recipe_id'] .'">' . $row['title'] . '</a></td>
			<td align=\"left\">' .$row['description'] .'</td>
			<td align=\"left\">' .$row['submitter'] .'</td>
		</tr>';
	}
	
echo '</table>';
//mysql_free_result ($mainresult); //  free up resources	

// make links to other pages
if ($num_pages > 1) {
	echo '<br /><p>';
			
	//determine which page the script is on
	$current_page = ($start/$display) + 1;
		
	//if it's not the first page, make a previous button
	if($current_page != 1) {
		echo '<a href="index.php?p=view_recipes&s='	. ($start - $display) . '&np= ' . $num_pages . '">Previous   </a> ';
	}
		
	//make all the numbered pages
	for ($i = 1; $i <= $num_pages; $i++) {
	if($i != $current_page) {
		echo '<a href="index.php?p=view_recipes&s=' . (($display * ($i - 1))) .	'&np=' . $num_pages . '">  ' . $i . '  </a>';
		} else {
			echo $i . ' ';
		}
	}
			
	// if it's not the last page, make a next button
	if($current_page != $num_pages) {
		echo '<a href="index.php?p=view_recipes&s=' . ($start + $display) . '&np=' . $num_pages . '">   Next</a>';
	}
		
	echo '</p>';
	}
	
} // End of while loop.
//echo '<pre' . print_r($_POST,1) . '<pre>';	
} else {

// Create a form allowing the user to select a category to view.
echo '<div align="left">
<form action="index.php?p=view_recipes" method="POST">
<select name="type">
<option value="NULL">Choose a category:</option>
';

	// Retrieve and display the available categories.
$catquery = 'SELECT * FROM categories ORDER BY category ASC';
$catresult = mysql_query ($catquery);
while ($row = mysql_fetch_array ($catresult, MYSQL_NUM)) {
	echo "<option value=\"$row[0]\">$row[1]</option>";
}	
//mysql_free_result ($catresult); //  free up resources
	
// Complete the form.
echo '</select>
<input type="submit" name="submit" value="submit">
<input type="hidden" name="submitted" value="TRUE">
</form>
</div>
';
} 


mysql_close();  // close database connection

?>

 

[mcquam]

anyone help?

 

[jpadie]

when you click on the 'next' link, you are firing a GET request. however your code exclusively checks for variables in the POST superglobal.
i recommend using GET for all idempotent actions. it is more SEO friendly amongst other reasons.

 

[mcquam]

Thanks jpadie. I changed to POST because I couldn't seem to combine my page switch:

    $url = BASE_URL . 'index.php?p=view_recipes';

with the GET syntax on the url. eg. localhost/oldmeg/index.php?p=view_recipes?s=5?np=3

So I changed it by using POST along with &s=5&np=3.

Is this wrong?

 

[jpadie]

there is no wrong or right but you cannot access the query string from the _POST superglobal.

 

[mcquam]

Can you tell me how I would change the next link for example? Can I do this?

'<a href="index.php?p=view_recipes?s=' . ($start + $display) . '?np=' . $num_pages . '">   Next</a>';

 

[jpadie]

1. don't specify the number of pages. recalculate it each time as the database could have changed in the interim. a properly optimised count query should be not be a significant processing overhead.

2. yes, the link mostly works as you have crafted it, although you concatenate query strings with an & not a ?

'<a href="index.php?p=view_recipes?s=' . ($start + $display)">   Next</a>';

i posted a paging solution on this forum a couple of weeks ago. you may find that it works better for your needs. you should find it in one of my later posts in this thread:

http://www.tek-tips.com/viewthread.cfm?qid=1569707

 

[mcquam]

Thanks again jpadie. I will certainly try your pagination. Can you help me out with what my GET statement would look like to accommodate the view_recipes switch along with the category choice and page numbers. Do I need to use separate pages now for example or can I self post?

 

[jpadie]

you never need to use a separate url. all forms and requests can be self-processing.

i assume you just want to add a category to the link

'<a href="index.php?p=view_recipes?s=' . ($start + $display)&amp;category=somecategory">   Next</a>';

or set the default category as a session variable and have it 'stick' until a user selects another category from the drop down.

 

[mcquam]

Thanks, that is most helpful.

I have changed the action to GET:

<form action="index.php?p=view_recipes" method="get">
<select name="type">

and I have now added hidden inputs:

<input type="hidden" name="s" value="' .$start . '">

This gives me a url which is nearly useful but misses out the pages switch "index.php?p=view_recipes". So, now I can get:

[URL unfurl="true"]http://localhost/oldmeg/index.php?type=1&submit=submit&s=1[/URL]

but what I need is:

[URL unfurl="true"]http://localhost/oldmeg/index.php?p=view_recipes&type=1&submit=submit&s=1[/URL]

I don't know what to change to do that.

 

[jpadie]

echo <<<HTML
<form action="index.php" method="get">
 <select name="type">
    <option></option>
 </select>
 <input type="hidden" name="p" value="view_recipes" />
 <input type="hidden" name="s" value="$start" />
</form>

 

[mcquam]

Of course! Thanks again.