Two PHP Questions - Sorting and Login

jrru2

1)I am working with a text file. In my PHP, I have exploded the contents of that text file, and inserted its contents into an array. One of the fields of this array is the date that the particular record was written to the text file. I just need to know how to sort the array by that date(which in the array is $line[0]).

2)I need an overview for to how to make a login page. There will only ever be two accounts logging in here(this is for a school project) - a user account and an admin account. I have already written the pages that each account will access, I just need to know how to write a login page where you type adminusername and adminpassword to access the admin pages and username and userpassword to access the user pages. And the password needs to be encrypted. If you could direct me to some actual examples of PHP code for a page like this, that would be great.

These are both for a project I'm doing for school that is due Monday, so I really need help with these things before then.

Thanks in advance.

planetsim

There is a reason you were given the project and it wasnt to get somebody other than yourself to do it. People will help you only if you help yourself by at putting in a good effort for trying to get it to work.

wilku

As it's your project, you should probably do some work for it 😉. So let me show you , where to start looking:
1) to sort an array - [man]usort[/man] is the function.
2) There are several things you could use - I prefer sessions:
- On a protected page (and every other page) start a session ([man]session_start[/man])
- check if a pair user-pass is stored in session and if they match
- if yes, display content
- if not, redirect to login form with [man]header[/man] (or display login form)
- in a script that process login data check the pair that came from the form and if it's correct, store it in session - at last redirect to desired page.

jrru2

Focusing just on the array sort I mentioned above...here is the code I have for the page so far, I'm trying to use usort, but the sort isn't working. I'm not even sure how it's supposed to work since all the records from the text file are never in the same array together....there's a loop that makes a one-dimensional array for each record every time through, so I'm not sure how I'm supposed to sort those records when they're never really in the same array together. Again, what I want to happen is, when the contents of the array are all outputted into the dynamically created table, I want them to be sorted by the date in which they were written to the text file(the date is in [0] of the array) from most recent to least recent. I know that what I have here for the sort shouldn't work, but I just don't know what to do to make it work.

<?php
//create short variable name
$DOCUMENT_ROOT = dirname($SERVER['PATH_TRANSLATED']);
?>
<html>
<head>
<title>Bob's Auto Parts - Feedback Results</title>
</head>
<body bgcolor="#00ffff">
<h1>Bob's Auto Parts</h1>
<h2>Feedback Results</h2>
<?php
$ftype = $POST['ftype'];
//Read in the entire file.
//Each order becomes an element in the array
$orders= file("$DOCUMENT_ROOT/comments.txt");
// count the number of orders in the array
$number_of_orders = count($orders);
if ($number_of_orders == 0)
{
echo '<p><strong>No feedback available.
Please try again later.</strong></p>';
}
echo "<table border=0 bgcolor=#00ff00 cellspacing=10>\n";
echo '<tr><th bgcolor="#00ff00">Date Of Comment</th>
<th bgcolor="#00ff00">Name</th>
<th bgcolor="#00ff00">E-Mail Address</th>
<th bgcolor="#00ff00">Feedback Type</th>
<th bgcolor="#00ff00">Comments</th>
<tr>';
$count = 0;
function DateCmp($a, $b)
{
return ($a[1] < $b[1]) ? -1 : 0;
}
for ($i=0; $i<$number_of_orders; $i++)
{
//split up each line
$line = explode( "\t", $orders[$i] );
//filter out feedbacktype

usort($line, 'DateCmp');
$tempStr = trim($line[3]);
$pos = "POSITIVES";
if (strcmp($tempStr,$ftype) == 0)

// output each order
{
echo "<tr><td>$line[0]</td>
<td align='right'>$line[1]</td>
<td align='center'>$line[2]</td>
<td align='center'>$line[3]</td>
<td align='right'>$line[4]</td>
</tr>";
$count = $count + 1;
}
}
if ($count==0)
echo("No $ftype Comments Found");
echo '</table>';

?>
</body>
</html>

phpmavenman

Let me see if I can get you pointed in the right direction:

$line = explode( "\t", $orders[$i] );

The above line is splitting the data specific to $orders[$i] into an array. When you run usort on $line you are only sorting the data for that one order (ie Name, Address, Amount, Date).

You need to first feed $line as a multidimensional array. I am going to give you some work to research on your own since this IS for school.

use the [man]list[/man] function (example #3) with your explode and walk all the $orders[] prior to usorting. That will get the data into one multi dimensional array that you can usort and then format for the page.

jrru2

Isn't the $orders array(created from the text file at the beginning before any exploding takes place) multidimensional? Is it possible to just run the sort on THAT instead, and then explode and display?

EDIT: I went ahead and tried that(sorting the $orders array) and it worked, only it only sorted the first two items of the array...i.e. when the final table displayed in the browser the first two lines were in order but the rest were not.

Code Snippet:

$orders= file("$DOCUMENT_ROOT/comments.txt");
// count the number of orders in the array
function DateCmp($a, $b)
{
return ($a[0] < $b[0]) ? -1 : 0;
}
usort($orders, 'DateCmp');

jrru2

Also, with regards to the login...

I have the actual login page working...I can log in as a user or admin and go the appropriate pages. What I'm trying to do now is that if someone who isn't logged in tries to access a page directly that would otherwise come only after login, I want the page to display an error message instead of fully loading. The way I'm trying to do this is with isset and an if statement as follows:

<?php
session_start();
if (isset($_SESSION['usrname']))
{ ... }
?>

What do I put where the dots are to make the rest of my page show up? It's not like I can just echo or print the whole page because it's too big/complex, right? So how do I display my page if the if statement returns true?

phpmavenman

[man]file[/man] actually reads a file line by line and creates an array of that file like you have with $quotes. You can test this by adding the following just after the file() function. I am saying this assuming that you have a standard ascii file that is tab delimited.

echo "<pre>";
var_dump($quotes);
echo "</pre>";

You will see in the results printed that you will have an array with all the data for each line of the file in a single string. The [man]list[/man] process will assist in breaking down $quotes further into a multidimensional array.

jrru2

Ok, well I put used the list function before the sort but it's still doing the same thing - leaving part of the array unsorted.

$orders= file("$DOCUMENT_ROOT/comments.txt");
// count the number of orders in the array
list($orders[0], $orders[1], $orders[2], $orders[3], $orders[4]) = $orders;
function DateCmp($a, $b)
{
return ($a[0] < $b[0]) ? -1 : 0;
}
usort($orders, 'DateCmp');

phpmavenman

Try this (I also modified your DataCmp function) This will sort the first column list in the text file:

$orders= file("$DOCUMENT_ROOT/comments.txt");
  // count the number of orders in the array
foreach($orders as $key=>$value)
{
  list($line[$key][0], $line[$key][1], $line[$key][2], $line[$key][3], $line[$key][4]) = explode("\t",trim($orders[$key]));
}
  function DateCmp($a, $b) 
{ 
    if ($a[0] == $b[0]) return 0;
    return ($a[0] < $b[0]) ? -1 : 1;
} 
  usort($line, 'DateCmp');

That should take care of the sort portion.

jrru2

That sorts it by the date, but from oldest to newest. I need from newest to oldest.

phpmavenman

Just change the conditional of $a[0] and $b[0]...instead of $a[0] < $b[0] make it like:

return ($a[0] > $b[0]) ? -1 : 1;

jrru2

Yeah, that's what I initially thought would change it, but when I tried it, it didn't change.

$orders= file("$DOCUMENT_ROOT/comments.txt");
// count the number of orders in the array
foreach($orders as $key=>$value)
{
list($line[$key][0], $line[$key][1], $line[$key][2], $line[$key][3], $line[$key][4]) = explode("\t",trim($orders[$key]));
}
function DateCmp($a, $b)

{

if ($a[0] == $b[0]) return 0;
return ($a[0] > $b[0]) ? -1 : 1;
}

usort($line, 'DateCmp');

phpmavenman

I attempted your script with a test txt file that I have with a numeric value as the first column. It resorted in descending order just fine. Not knowing the exact layout of your content in your text file it is hard to determine the problem but the script works fine for me.

jrru2

This is the format of what is in the first column, if that helps. The rest of the columns are just normal text.

18:03, 19th April

Since there are both letters and numbers in this, should I be doing my comparisons(within the Datecmp function) as strings?

EDIT: I tried comparing them as strings but it made no difference.