Help: prev|next with array and session

[an00p]

Hello Friends,

I want the following issue to be resolved:

1. page results.php shows the users list (sql query results). This page also stores all user_id to an array $_SESSION. And when I click to view details of a user, user_view.php shows the details of that user.

2. I want the user details to be changed in user_view.php page when I click on (prev|next) links.

What I have achieved:

1. I am using user_view.php?prev=1 for `prev` link and user_view.php?next=1 for `next` link.
2. I am checking on top of the user_view.php page to see if $_GET or $_GET is set.

in results.php page following variables were set

$_SESSION['user_ids']=$user_ids; // $user_ids is an array with ids
$_SESSION['first_value']=reset($user_ids);
$_SESSION['last_value']=end($user_ids);

in user_view.php page following checks were being performed

$id_view=$_SESSION['user_id']; // This is to view the first user details and is set after clicking "view" for a user in results.php page

$user_ids=$_SESSION['user_ids']; // array
if (isset($_GET['prev']))
{
	if ($_GET['prev'] == "1")
	{
		if (current($_SESSION['user_ids'])==$_SESSION['first_value'])
		{
			$id_view = $_SESSION['user_value'];
		}
		else
		{
			$id_view = prev($_SESSION['user_ids']);
		}
	}
}
if (isset($_GET['next']))
{
	if ($_GET['next'] == "1")
	{
		if (current($_SESSION['user_ids'])==$_SESSION['last_value'])
		{
			$id_view = $_SESSION['user_value'];
		}
		else
		{
			$id_view = next($_SESSION['user_ids']);
		}
	}
}

// GET THE DETAILS OF THE USER WITH ID $id_view
$result=mysql_query("SELECT * FROM $tbl_name WHERE user_id='$id_view'",$db);

Above code is not working at all...

What I want:
Change the $id_view value when I click on prev|next links and display the details in that page.

Can you guys help me??

[ddymacek]

cant go into too much detail on your code, but... debug.

if (isset($_GET['prev']))
  echo $_GET['prev'];
  if ($_GET['prev'] == "1") {
      echo "true";
  } else {

[ddymacek]

echo "false
}

bad post....

[ddymacek]

discover your values in your variables and see if what you expect is there.

[diafol]

prev, current etc don't store across page refreshes. you can store the values in session vars, but you can't move the pointer without a bit of trickery. key() would probably be your best bet. Still, v. tricky.

[an00p]

prev, current etc don't store across page refreshes. you can store the values in session vars, but you can't move the pointer without a bit of trickery. key() would probably be your best bet. Still, v. tricky.

I am already playing with key now :)

Can you share some knowledge on how keys will be handy in this situation? It would be really helpful.

[diafol]

key() will store the pointer or 'key position'. I don't know of any easy way to set the pointer on page refresh. I had a play with key loops using next as an 'incrementer' followed by a single prev. It worked, but it's really messy and you could end up with an infinite loop if there's a change to the underlying array.

Here's a session-based bit of code - it's raw and uses the actual session vars themselves (not good), but it'll give you the idea:

<?php
//variables
$allowed = array("first","prev","last","next");
$f = '<a href="?s=first">First</a>';
$p = '<a href="?s=prev">Previous</a>';
$n = '<a href="?s=next">Next</a>';
$l = '<a href="?s=last">Last</a>';

//check or initialise session vars
if(!isset($_SESSION['ids'])){
	$_SESSION['ids'] = range(1,20); //place your default array here if req'd
}
if(!isset($_SESSION['key'])){
	$_SESSION['key'] = 0; //place current key at start
}

//check action - only actions where s=first, s=next etc. allowed
//protects against silliness in querystring by user
//although may be useless for bookmarking
if(isset($_GET['s']) && in_array($_GET['s'],$allowed)){
	switch($_GET['s']){
		case "first":
			$_SESSION['key'] = 0;
			break;
		case "prev":
			if($_SESSION['key']>0)$_SESSION['key']--;
			break;
		case "next":
			if($_SESSION['key']<count($_SESSION['ids']) - 1)$_SESSION['key']++;
			break;
		case "last":
			$_SESSION['key'] = count($_SESSION['ids']) - 1;
			break;		
	}	
}
//output the value
echo $_SESSION['ids'][$_SESSION['key']] . "<br />";
//output the navigation
if($_SESSION['key'] == 0){
	$out = "$n | $l";
}elseif($_SESSION['key'] == count($_SESSION['ids']) - 1){
	$out = "$f | $p";	
}else{
	$out = "$f | $p | $n | $l";
}
echo $out;
?>