有关PHP MVC文件连接的问题

I am trying to create a PHP MVC App which has a file structure like this

in init.php I have

<?php
include('app/Database.php');
include('app/models/m_template.php');
include('app/models/m_categories.php');

$Database = new Database();
$Template = new Template();
$Categories = new Categories($Database);

in m_tenplate.php I have Template() class like this to load files.

class Template
{

    function __construct() {}

    public function load($url, $title = '')
    {
        if ($title != '') { $this->set_data('page_title', $title); }
        include($url);
    }

and in m_vcategories.php I have Categoty() class like

class Categories {
    function __construct() {}

    public function test(){
        echo 'This is Test';
    }

in index.php I have

<?php
include 'app/init.php';
$Template->load('app/views/v_home.php');

now when I try to access the Categories() methods through v_home.php in Views like:

<?php
$Categories->test();

I am getting following errors

can you please let me know why this is happening?

$Categories is outside of the load methods scope, which also means it is out of scope for any files included within the load methods body.

Here is a solution which you could use to work around this:

// Add a $variables parameter to your load method.
public function load($url, $title = '', $variables=NULL)
{
    if( is_array($variables) )
    {
        foreach( $variables as $key => $item )
        {
            $$key = $item;
        }
    }
    if ($title != '') { $this->set_data('page_title', $title); }
    include($url);
}

Then you use the load method like this:

<?php
include 'app/init.php';
$Template->load('app/views/v_home.php', '', array('Categories' => $Categories);

You put an associative array of items you would like to make available to the template page.

The variable categories isn't available at v_home scope, to achieve this you need to add new parameter to your Template class - in load method and extract the contents of that variable, it will be like this

public function load($url, $title = '',$data = array())
{
    extract($data);
    if ($title != '') { $this->set_data('page_title', $title); }
    include($url);
}

http://php.net/manual/en/function.extract.php

then in index.php you can do this

<?php
include 'app/init.php';
$Template->load('app/views/v_home.php','',array('Categories' => $Categories));

or

<?php
include 'app/init.php';
$Template->load('app/views/v_home.php','',compact('Categories'));