[RESOLVED] Not displaying selected user's information

cybastud

Hi,

I need help with part of the following php

<?php
include('user.php');

$user = new User();    // new instance of User
$names = $user->retrieveNames();                

echo "<form Method='POST' ACTION='test.php'>";
echo "<select name='title' type='text' />";
foreach ($names as $name) {
    echo '<option>' .$name. '</option>';
}
echo "</select>";
echo "<br /><br />";
echo "<input type='submit' name='submit' value='Submit' />";
// the above works fine and lists the first_name and last_name correctly in the list
$Submit = $_POST['submit'];
if (isset($_POST['submit'])) {
// this is where I need help, it does not display the user information	
$user = new User();
$user->getUserById($ID);
echo "<p>User known as: " .$user->getDisplayName(). "<p>";

$friends = $user->getFriends();
echo "<p>Friends with: ".implode(',',$friends). "</p>";

$user->getUserById($ID);
echo "<p>User Know as: " .$user->getDisplayName(). "</p>";

echo "<p><a href='oop4.php'>Return</a></p>";
echo "</form>";
}
?>

user.php

<?php
class User{

public function getUserById($user_id){
$sql = 'select first_name, last_name, display_name from users where user_id = '.$user_id;
                $results = mysql_query($sql);
                $row = mysql_fetch_array($results);
                $this->user_id = $user_id;
                $this->fist_name = $row['first_name'];
                $this->last_name = $row['last_name'];
                $this->display_name = $row['display_name'];
                return true;
}

public function getDisplayName(){
                return $this->display_name;
}

public function getFriends(){
                $sql = 'select friend_id from user_friends where user_id = '.$this->user_id;
                $results = mysql_query($sql);
                $friends = array();
                while($row = mysql_fetch_array($results)){
                                $friends[] = $row['friend_id'];
                }
                return $friends;
}


public function retrieveNames()
{
     $sql = "select first_name, last_name from users"; //first_name and last_name is the fields of the database i need to list
     $qry = mysql_query($sql);

 while ($row = mysql_fetch_array($qry)) {
         // place all 'name' values selected in an array called
         // $names
         $names[] = $row['first_name'].$row['last_name'];
 }

 return $names;
}

}

?>

Any assistance will be aprreciated

Thanks

Derokorian

// this is where I need help, it does not display the user information     

$user = new User(); 
$user->getUserById($ID);

Where is $ID defined?

cybastud

Thanks

I've changed it to

<?php
//error_reporting(0); // turn error messages off
include('user.php');

$user = new User();    // new instance of User
$names = $user->retrieveNames();                

echo "<form Method='POST' ACTION='oop4.php'>";
echo "<select name='title' type='text' />";
foreach ($names as $name) {
    echo '<option>' .$name. '</option>';
}
echo "</select>";
echo "<br /><br />";
echo "<input type='submit' name='submit' value='Submit' />";

$Submit = $_POST['submit'];
if (isset($_POST['submit'])) {
$user = new User();
$user->getUserById($user_id);
echo "<p>User known as: " .$user->getDisplayName(). "<p>";

$friends = $user->getFriends();
echo "<p>Friends with: ".implode(',',$friends). "</p>";

$user->getUserById($user_id);
echo "<p>User Know as: " .$user->getDisplayName(). "</p>";

echo "<p><a href='test2.php'>Return</a></p>";
echo "</form>";
}
?>

It still does not display anything when I select the user

traq

same problem -- where is [font=monospace]$user_id[/font] defined?

changing the name of the variable doesn't help if the variable still doesn't exist. Try replacing this with a known user ID so you can see if the method itself is actually working.

you would be getting some useful feedback, I think, if your [font=monospace]getUserById()[/font] method didn't automatically return "true" - if no user is found, you should at least return "false" so you can know what's going on.

also, when you say it "does not display anything," do you mean that it's not printing the user info, or that it literally stops printing anything? In the latter case, you're probably running into an error. Make sure to set [font=monospace]error_reporting( -1 );[/font] so you can see all your error messages during development.

cybastud

ok thanks, I've defined user_id now:

<?php
//error_reporting(0); // turn error messages off
include('user.php');

$user = new User();    // new instance of User
$names = $user->retrieveNames();                

echo "<form Method='POST' ACTION='oop4.php'>";
echo "<select name='title' type='text' />";
foreach ($names as $name) {
    echo '<option>' .$name. '</option>';
}
echo "</select>";
echo "<br /><br />";
echo "<input type='submit' name='submit' value='Submit' />";

$Submit = $_POST['submit'];
if (isset($_POST['submit'])) {
	//header("location:user_find.php"); // redirects to the user_find.php page
$user = new User();
$user_id = $user->getUserById($user_id);
echo "<p>User known as: " .$user->getDisplayName(). "<p>";

$friends = $user->getFriends();
echo "<p>Friends with: ".implode(',',$friends). "</p>";

$user->getUserById($user_id);
echo "<p>User Known as: " .$user->getDisplayName(). "</p>";

echo "<p><a href='test.php'>Return</a></p>";
echo "</form>";
}
?>

and now it displays the following, no matter which user I select from the drop down list

User known as:

Friends with:

User Known as: Peter Pan

Return

user.php

<?php
class User{

public function getUserById($user_id){
$sql = 'select first_name, last_name, display_name from users where user_id = '.$user_id;
                $results = mysql_query($sql);
                $row = mysql_fetch_array($results);
                $this->user_id = $user_id;
                $this->fist_name = $row['first_name'];
                $this->last_name = $row['last_name'];
                $this->display_name = $row['display_name'];
                return true;
}

public function getDisplayName(){
                return $this->display_name;
}

public function getFriends(){
                $sql = 'select friend_id from user_friends where user_id = '.$this->user_id;
                $results = mysql_query($sql);
                $friends = array();
                while($row = mysql_fetch_array($results)){
                                $friends[] = $row['friend_id'];
                }
                return $friends;
}


public function retrieveNames()
{
     $sql = "select first_name, last_name from users"; //first_name and last_name is the fields of the database i need to list
     $qry = mysql_query($sql);

 while ($row = mysql_fetch_array($qry)) {
         // place all 'name' values selected in an array called
         // $names
         $names[] = $row['first_name'].$row['last_name'];
 }

 return $names;
}

}

?>

bradgrafelman

I still don't see where you've defined $user_id before this line:

$user_id = $user->getUserById($user_id);

traq

$user_id = $user->getUserById($user_id);

The second [font=monospace]$user_id[/font] on this line is undefined. You don't define it anywhere (in the code you've shown us) before this line. It's the same as passing NULL to the function. Did you turn on error reporting as I suggested? Are you getting an error message along the lines of "Notice: Undefined variable: $user_id in ..."?

As for the first [font=monospace]$user_id[/font], the end result of this line of code is that it will be assigned the value of TRUE (since your [font=monospace]getUserById()[/font] method always returns TRUE).

HOWEVER:

This probably isn't the value you need (I'm assuming you need an integer).
It's too late anyway: you already ran your DB query.

You need to define variables before you use them. If [font=monospace]$user_id[/font] is actually defined elsewhere in your code, before you try to use it, please show us the relevant lines. It would seem to me, however, that you simply haven't defined it yet.

cybastud

Is that not defining the variable? Sorry I'm new to php and a bit confused...how do I define the variable, and do I need to in order for the function to work properly?

traq

$user_id = 1;
$user->getUserById( $user_id );

If there are any users in your database, there's probably a user with user_id = 1. Let me know if this works.

BUT FIRST, please add [font=monospace]error_reporting( -1 );[/font] as the first line of code after your <?php tag.

IF this works, then your function works (if not very well). To make it dynamic, you need to decide how the code is supposed to know which user it's supposed to look for (it can't guess), and make [font=monospace]$user_id = [/font]whateverUserIdNumberYouWantToFind.

----------------------------Edit:

cybastud wrote:
Is that not defining the variable?

yes, but as I said:
...it's still not defined when you're trying to use it (assignment doesn't happen until after the assignment is complete: so the second time you write $user_id on that line, it still "doesn't exist yet").

...it assigns $user_id the value of TRUE, which isn't useful for what you're trying to do.

cybastud

Thanks and yes I turned on error reporting and it gave me the Notice: Undefined variable: $user_id error, i tried the above now and it works but I have 7 users in my db and which ever user I select it needs to display the corresponding data, right now because I did $user_id = 1; I only get the info for the user id 1, how do I change this so whichever user I select from the options list I get there info...here is the output I got for user_id 1

User known as: Peter Pan

Friends with: 3,5

User Known as: Peter Pan

and here is the output if I have user_id = 2

User known as: King of Rock

Friends with: 2,5

User Known as: Peter Pan

traq

cybastud wrote:
...how do I change this so whichever user I select from the options list I get there info

traq;11001142 wrote:
To make it dynamic, you need to decide how the code is supposed to know which user it's supposed to look for (it can't guess), and make [font=monospace]$user_id = [/font]whateverUserIdNumberYouWantToFind.

[emphasis added]

if you're trying to select a name from the form you just made, you're out of luck: you don't have any user_ids to choose from in that form.

Either add them as the option values, or write a new method that looks for users by name (what your form calls title, for some reason) instead of by user_id.

cybastud

Yes, how do I add them as option values?

traq

when you build your form, select the ids from the database along with the names.
write the ids as the value of each option in your select list.
when your form is submitted, you can use [font=monospace]$_POST['title'][/font] (or, rename your select list to something more appropriate -like user_id maybe- and use that index) to access them.

cybastud

ok cool, I've changed my retrieveNames() function in the user.php to include the user_id as well then write it to the options list. I've also renamed the $POST['title'] to $POST['user_id'] but now I dont know how to use that index to access the user_id

user.php

<?php
class User{

public function getUserById($user_id){
$sql = 'select first_name, last_name, display_name from users where user_id = '.$user_id;
                $results = mysql_query($sql);
                $row = mysql_fetch_array($results);
                $this->user_id = $user_id;
                $this->fist_name = $row['first_name'];
                $this->last_name = $row['last_name'];
                $this->display_name = $row['display_name'];
                return true;
}

public function getDisplayName(){
                return $this->display_name;
}

public function getFriends(){
                $sql = 'select friend_id from user_friends where user_id = '.$this->user_id;
                $results = mysql_query($sql);
                $friends = array();
                while($row = mysql_fetch_array($results)){
                                $friends[] = $row['friend_id'];
                }
                return $friends;
}


public function retrieveNames()
{
     $sql = "select user_id, first_name, last_name from users"; //first_name and last_name is the fields of the database i need to list
     $qry = mysql_query($sql);

 while ($row = mysql_fetch_array($qry)) {
         // place all 'name' values selected in an array called
         // $names
         $names[] = $row['user_id']. ". ".$row['first_name'].$row['last_name'];
 }

 return $names;
}

form

<?php
//error_reporting(0); // turn error messages off
include('user.php');

$user = new User();    // new instance of User
$names = $user->retrieveNames();                

echo "<form Method='POST' ACTION='oop4.php'>";
echo "<select name='user_id' type='text' />";
foreach ($names as $name) {
    echo '<option>' .$name. '</option>';
}
// now it displays the user ids along with name and surname
echo "</select>";
echo "<br /><br />";
echo "<input type='submit' name='submit' value='Submit' />";

if (isset($_POST['user_id'])) { // is this right?
$user = new User();
$user_id = 1; // what should I do here?
$user_id = $user->getUserById($user_id);
echo "<p>User known as: " .$user->getDisplayName(). "<p>";

$friends = $user->getFriends();
echo "<p>Friends with: ".implode(',',$friends). "</p>";

$user->getUserById($user_id);
echo "<p>User Known as: " .$user->getDisplayName(). "</p>";

echo "<p><a href='test.php'>Return</a></p>";
echo "</form>";
}
?>

traq

this:

$names[] = $row['user_id']. ". ".$row['first_name'].$row['last_name'];

writes the user_id into a string along with the user's name. This will make it difficult to use later on.

Instead, just pass the user_id and name separately:

$names[] = array( $row['user_id'], $row['first_name'].$row['last_name'] );

Then, when you build your select box, use the user_id as the value of the option, leaving the name as the option text
(note I also changed some of your HTML markup that was incorrect):

$select_box = '<select name="user_id">';
foreach ($names as $name) {
    // remember, $name is now an array holding the user_id and name
    list( $uid,$uname ) = $name;
    $select_box .= '<option value="'. $uid .'">'. $uname .'</option>';
}
$select_box .= "</select>"; 
print $select_box;

when the form is submitted:

if (isset($_POST['user_id']) && ctype_digit( $_POST['user_id'] )) {
// the ctype_digit() check makes sure the user_id is numeric:
//   (I'm assuming all your user_ids are integers)
//   if other characters are submitted, then something fishy is going on
//   This also means that (being only numbers) it's safe for the database query
$user = new User();
$user_id = $_POST['user_id'];
// since we don't use the return value of your getUserById() method,
//    there's no reason to assign it to a variable
$user->getUserById($user_id); 
// and so forth

cybastud

Great! It works.

And thanks again for all the help, much appreciated