php undefined variable error when calling class method - php

Question

I have been writing procedural php for years and am very comfortable with it. Recently I decided to rework an existing site and switch to PDO and OOP. Everyone is telling me that this is a better way to go but the learning curve is killing me. When trying to call a class, I get the following.
Menu Builder
vbls: 5 1
Notice: Undefined variable: Menu in /home/lance/DallyPost/projectWebSite/trunk/1/core/modules/menuBuilder.php on line 9
Fatal error: Call to a member function menuFramework() on a non-object in /home/lance/DallyPost/projectWebSite/trunk/1/core/modules/menuBuilder.php on line 9
The procedure is that I have included menu.php at the top of index.php, prior to including the following script:
<?php
//menuBuilder.php
echo"<h2>$pageTitle</h2>";
$pub = $_URI_KEY['PUB'];
$dir = $_URI_KEY['DIRECTORY'];
echo"vbls: $pub $dir";
if($Menu->menuFramework("$pub", "$dir") === false) {
echo"The base menu framework failed to build correctly.";
}
else{
echo"<p>The base menu framework has been successfully constructed.</p>";
}
?>
As you can see, the above script calls a method in the Menu class:
<?php
//menu.php
class Menu{
private $db;
public function __construct($database) {
$this->db = $database;
}
public function menuFramework($pub, $directory){
$link = "/" . $directory . "/index.php/" . $pub . "/home/0/Home-Page/";
$inc = "core/menus/" . $pub . "category.php";
$file = "core/menus/" . $pub . "menuFramework.php";
$text = "<nav class=\"top-bar\" data-topbar>";
$text .= "<ul class=\"title-area\">";
$text .= "<li class=\"name\">";
$text .= "<h1>Home Page</h1>";
$text .= "</li>";
$text .= "</ul>";
$text .= "include($inc)";
$text .= "</nav>";
//write text to a file
if(file_put_contents($file, $text)){
return true;
}
else{
return false;
}
}
... rest of file not shown
Can you help me understand why I am getting this error. My understanding is that the variable was or should have been defined when I included menu.php, which was done before which was called a the top if index.php
Thanks

Answer 1

add this at the top of the script
$menu = new Menu($dbHandle);

Answer 2

That's not how classes work. You can't reference an entire class, Menu, with a variable, $Menu, to invoke instance methods.
You need to create an instance of your class on which to invoke methods:
$menu = new Menu(...);
You can create class-level "static" methods which are invoked on the class itself, but that syntax doesn't involve $Menu. You would use Menu::method_name() for that.

Answer 3

You are calling $Menu->
so your are a calling a variable called Menu, instead of the class Menu.
anyways, that function is not static, so you need to instantiate an object.
For that, add a this line:
$menu = new Menu($db);
where $db is your database object, if you really need it, or null if you dont (i cannot say with that code fragment)
and then call
$menu->menuFramework(...)