Confused myself with another OOP/MySQL problem

[Radon3k]

Basically there's a link that will say blah.php?someid=$id. Well the link displays correctly but when you click the link, nothing happens. Here's the code:

function showFullArticle()
  {
    if($_GET['articleid'] == '')
    {
      echo("<p><b>Current articles:</b></p>");
      $articles = new articles();
      $articles->showQuickArticles();
      echo("</p>");
    } else {
      if($_GET['articleid'] == '$id')
      {
        $connection = new mysqlConnection();
        $connection->connect();
        $getArticle = $connection->query("SELECT * FROM articles WHERE `articleid` = '$id'");

    $this->row = mysql_fetch_array($getArticle);
    $this->title = $this->row['title'];
    echo($this->title);
 }
   }
  }

I'm honestly not sure what I'm doing wrong in this. I've tried numerous differen't ways and they all seem to be the same. Any help would be appreciated. Thanks!

[drew010]

in this line
if($GET['articleid'] == '$id')
the variable $id doesn't exist, so the if statment is basically saying
if ($GET['articleid'] == "")...

[konsu]

i neither understand the problem nor do i know how this function is used, but one line seems suspicious:

if($_GET['articleid'] == '$id')

are you comparing $_GET['articleid'] with the literal '$id'?

[Radon3k]

drew010: If the variable doesn't exist then it's supposed to let another function take over. If it does exist then I want it to pull up the appropriate article from the database.

konsu: I guess I am, I'm really not sure what I was supposed to do there. 😕

[konsu]

Radon3k wrote:

I guess I am, I'm really not sure what I was supposed to do there. 😕

pass in $id as parameter. and remove the quotes around it.

[Radon3k]

Sorry, I don't understand. What do you mean by pass it in as a parameter?

[konsu]

introduce a parameter to this function and call it with the value for $id:

function showFullArticle($id) { ... }

[Radon3k]

Ah I see what you mean. What would I do then? I don't think that would work very well given how the code in the other file is setup. It actually just starts a new instance of the class, here's the code:

            $articles = new articles();
            $show = $articles->showFullArticle();

[konsu]

where the variable $id is coming from? it is not defined anywhere in the function that you provided. is it a member variable in the class "articles"? what is "showFullArticle()"? is it a member function of class "articles"? if so, why does it create another instance of the class "articles" inside? the code sample that you provided is not sufficient for me to understand the problem. anyway, $id must be defined when this function is called otherwise it won't work.

[Radon3k]

I apologize for not providing all of the information. Let me try to explain where I can and provide code where necessary. $id is a variable in class articles and is set in a link in another function in class articles. The link looks like this:

<a href="articles.php?articleid=$id"></a>

I'm not sure why I created another instance of the class articles inside the same class, I guess I wasn't sure how to call a function inside a function of a class. I believe I understand what you are saying in that the $id variable must be set for this to properly work, however I'm not sure where it's set, if at all, and if it isn't, where to set it. Hopefully this provides you with a little more information, I apologize if it's confusing and if it is then I'll do my best to explain it more thoroughly. I appreciate the help! 🙂

[konsu]

your code is in articles.php? and the article id is coming from the request in the url's query string?

to invoke a class method from another method on this class, just use $this->method() syntax. take a look at http://us2.php.net/manual/en/language.oop.php.

[Radon3k]

This is the code contained in articles.php:

 $articles = new articles();
            $show = $articles->showFullArticle();  

The rest of the code is contained in class.php.

Thanks for the pointer about invoking a method within a class!

Any suggestions for how to fix this or do you still need more information? Thanks! 🙂

[konsu]

something like

$articles = new articles();
$show = $articles->showFullArticle($_REQUEST['articleid']);

but in your showFullArticles() method you compare $_REQUEST['articleid'] with a non-existent $id. was this if statement supposed just to check if article id is not empty? it looks like you do not need this "if".

[Radon3k]

The If statement was supposed to say that if the link was clicked and it contained an ID number to retrieve that article from the database and display it.

[Radon3k]

Is anybody able to lend a hand?

[konsu]

what is the question? i thought everything has been sorted out. ; -)

[Radon3k]

It doesn't work and I'm still unsure as to what part is the part that needs fixing and a general idea of how to fix it.

[konsu]

could you post the code for the class and the code that invokes the class?

[Radon3k]

Sure, here's the code for class articles. Two of the functions in there (showQuickArticles and showRecentArticles) are basically the same function except some minor differences. I wasn't sure how to achieve what I wanted by using one function, so I used two. Anyway, here's the code:

class articles
{
  var $id = '';
  var $category = '';
  var $title = '';
  var $author = '';
  var $article = '';
  var $row = NULL;

  function showFullArticle()
  {
    if($_GET['articleid'] == '')
    {
      echo("<p><b>Current articles:</b></p>");
	  $articles = new articles();
      $articles->showQuickArticles();
	  echo("</p>");
    } else {
      if($_GET['articleid'] == '$this->id')
      {
        $this->id = $_GET['articleid'];
        $connection = new mysqlConnection();
        $connection->connect();
        $getArticle = $connection->query("SELECT * FROM articles WHERE `articleid` = '$this->id'");

    $this->row = mysql_fetch_array($getArticle);
    $this->title = $this->row['title'];
    echo($this->title);
 }
   }
  }

  function showQuickArticles()
  {
    $connection = new mysqlConnection();
    $connection->connect();
    $getArticles = $connection->query("SELECT articleid,title,author,date FROM articles ORDER BY date,title,author ASC");

while($this->row = mysql_fetch_array($getArticles))
{
  $this->id = $this->row['articleid'];
  $this->title = $this->row['title'];
  $this->author = $this->row['author'];
  echo("<b><a href='articles.php?articleid=$this->id'>$this->title</a></b> ... by $this->author<br />");
}
  }

  function showRecentArticles()
  {
    $connection = new mysqlConnection();
    $connection->connect();
    $getArticles = $connection->query("SELECT title,author,date FROM articles ORDER BY date,title,author ASC LIMIT 5");

while($this->row = mysql_fetch_array($getArticles))
{
  $this->title = $this->row['title'];
  $this->author = $this->row['author'];
  echo("<b>$this->title</b> ... by $this->author<br />");
}
  }
}

[konsu]

1. in php, anything between single quotes is a literal string. in your code '$this->id' is a literal string. what was your intention here? $this->id perhaps? as it is right now, the code checks if the global variable 'articleid' that was passed with the url is equal to the string '$this->id'. the code does not compare it to $this->id as you probably wanted.
2. $this->id is initialised to be the empty string in the class, and is never changed.