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File: example.php

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  Classes of Rubens Takiguti Ribeiro  >  Friendly class  >  example.php  >  Download  
File: example.php
Role: Example script
Content type: text/plain
Description: Simple example
Class: Friendly class
Provide friend access to protected functions
Author: By
Last change: Accessible without user login
Date: 6 years ago
Size: 5,528 bytes
 

Contents

Class file image Download
<?php
/**
 * This example creates tree classes and two function:
 * - class point: has two friendly methods (set_x and set_y);
 * - class line: is a friend class of set_x and set_y methods;
 * - class other: is not a friend class of set_x and set_y methods;
 * - function good: is a friend function of set_x method only;
 * - function bad: is not a friend function of set_x and set_y methods.
 */
require_once('friendly_class.class.php');


/**
 * POINT: has two friendly methods (set_x and set_y).
 */
class point extends friendly_class {
    private
$x;
    private
$y;

   
/**
     * Specify wich method is friendly.
     */
   
protected function is_friendly_method($method) {
        switch (
$method) {
        case
'set_x':
        case
'set_y':
            return
true;
        }
        return
false;
    }

   
/**
     * Specify wich class is friend of each friendly method.
     */
   
protected function is_friend_class($class, $method) {
        switch (
$class) {
        case
'line':
            switch (
$method) {
            case
'set_x':
            case
'set_y':
                return
true;
            }
            break;
        }
        return
false;
    }


   
/**
     * Specify wich function is friend of each friendly method.
     */
   
protected function is_friend_function($function, $method) {
        switch (
$function) {
        case
'good':
            switch (
$method) {
            case
'set_x':
                return
true;
            }
            break;
        }
        return
false;
    }

// Simple public methods

   
public function __construct($x, $y) {
       
$this->set_x($x); // OK: access from owner class
       
$this->set_y($y); // OK: access from owner class
   
}

    public function
get_x() {
        return
$this->x;
    }

    public function
get_y() {
        return
$this->y;
    }

// Friendly methods

   
protected function set_x($x) {
       
$this->x = (float)$x;
    }

    protected function
set_y($y) {
       
$this->y = (float)$y;
    }
}


/**
 * LINE: is a friend class of set_x and set_y methods.
 */
class line {
    private
$start;
    private
$end;

    public function
__construct($x0, $y0, $x1, $y1) {
       
$this->start = new point($x0, $y0);
       
$this->end = new point($x1, $y1);
    }

   
// Calling friendly method
   
public function set_start($x, $y) {
       
$this->start->friend_set_x($x); // OK: line is friend of set_x
       
$this->start->friend_set_y($y); // OK: line is friend of set_y
   
}

   
// Calling friendly method
   
public function set_end($x, $y) {
       
$this->end->friend_set_x($x); // OK: line is friend of set_x
       
$this->end->friend_set_y($y); // OK: line is friend of set_y
   
}

    public function
get_start() {
        return array(
$this->start->get_x(), $this->start->get_y());
    }

    public function
get_end() {
        return array(
$this->end->get_x(), $this->end->get_y());
    }
}


/**
 * OTHER: is not a friend class of set_x and set_y methods.
 */
class other {
    private
$point;

    public function
__construct($x, $y) {
       
$this->point = new point($x, $y);
    }

    public function
set_point($x, $y) {
       
$this->point->friend_set_x($x); // WARNING: other is not friend of set_x
       
$this->point->friend_set_y($y); // WARNING: other is not friend of set_y
   
}

    public function
get_point() {
        return array(
$this->point->get_x(), $this->point->get_y());
    }
}


/**
 * GOOD: is a friend function of set_x method only.
 */
function good() {
   
$g = new point(1, 2);
   
$g->friend_set_x(3); // OK: good is friend of set_x
   
$g->friend_set_y(4); // WARNING: good is not friend of set_y
   
echo '<p>G: '.$g->get_x().','.$g->get_y().' / Expected: 3,2</p>';
}


/**
 * BAD: is not a friend function of set_x and set_y methods.
 */
function bad() {
   
$b = new point(3, 4);
   
$b->friend_set_x(5); // WARNING: bad is not friend of set_y
   
$b->friend_set_y(6); // WARNING: bad is not friend of set_y
   
echo '<p>B: '.$b->get_x().','.$b->get_y().' / Expected: 3,4</p>';
}


/// Test friend classes and friend functions
echo '<h1>Test page</h1>';

// Test access from "point" (direct access)
echo '<h2>Test access from "point" (direct access) (2 warnings)</h2>';
$p = new point(1, 2);
$p->friend_set_x(3); // WARNING: can not be called directly
$p->friend_set_y(4); // WARNING: can not be called directly
echo '<p>P: '.$p->get_x().','.$p->get_y().' / Expected: 1,2</p>';
echo
'<hr />';

// Test access from "other"
echo '<h2>Test access from "other" (2 warnings)</h2>';
$other = new other(5, 6);
$other->set_point(7, 8); // WARNING!
$point = $other->get_point();
echo
'<p>Other: '.$point[0].','.$point[1].' / Expected 5,6</p>';
echo
'<hr />';

// Test access from "line"
echo '<h2>Test access from "line" (no warnings)</h2>';
$line = new line(9, 10, 11, 12);
$line->set_start(13, 14);
$line->set_end(15, 16);
$start = $line->get_start();
$end = $line->get_end();
echo
'<p>Line Start: '.$start[0].','.$start[1].' / Expected 13,14</p>';
echo
'<p>Line End: '.$end[0].','.$end[1].' / Expected 15,16</p>';
echo
'<hr />';

// Test access from "bad"
echo '<h2>Test access from "bad" (2 warnings)</h2>';
bad(); // WARNING!
echo '<hr />';

// Test access from "good"
echo '<h2>Test access from "good" (1 warning)</h2>';
good(); // WARNING!