Is this a correct implementation of the Strategy pattern? - php

Below is the implementation in PHP. I aim to have a different coupon code and a different discount returned, based on the type of book (vintage or new).
<?php
interface BookOffer {
function generateCoupon();
function generateDiscount();
}
class VintageBookOffer implements BookOffer {
function generateCoupon() {
return "VINTAGECOUPONCODE";
}
function generateDiscount() {
return 10.0;
}
}
class NewBookOffer implements BookOffer {
function generateCoupon() {
return "NEWBOOKCOUPONCODE";
}
function generateDiscount() {
return 5.0;
}
}
class OfferGenerator {
function generateOffer($bookType) {
if($bookType == "vintage") {
$bookObject = new VintageBookOffer();
}
else if($bookType == "newbook") {
$bookObject = new NewBookOffer();
}
return $bookObject;
}
}
$bookType1 = "vintage";
$bookType2 = "newbook";
$offerGenerator = new OfferGenerator();
$bookOffer1 = $offerGenerator->generateOffer($bookType1);
$bookOffer2 = $offerGenerator->generateOffer($bookType2);
echo "You chose book type " . $bookType1 . ". Your coupon code is " . $bookOffer1->generateDiscount() . ", and your discount is " . $bookOffer1->generateCoupon();
echo "You chose book type " . $bookType2 . ". Your coupon code is " . $bookOffer2->generateDiscount() . ", and your discount is " . $bookOffer2->generateCoupon();
?>
Does this look correct? I believe it is. But any feedback from the community would be welcome. The only reason I think it might be incorrect is because it does not use type hinting, which is frequently seen in the Strategy Pattern.

Related

Method is not compatible with method intelephense(1038) [duplicate]

This question already has answers here:
Fatal error: Declaration of .. must be compatible with .. PHP
(6 answers)
Closed last year.
VSCode doesn't accept a child and parent method with the same name but they have the same purpose.
The book I use doesn't use different name for this exercise and I don't understand why it doesn't work with me.
I found a solution by giving a different name to the child method but it doesn't help me to understand the problem.
Index.php
function monAutoLoad($class) {
include(str_replace("\\", "/", $class). ".php");
}
spl_autoload_register('monAutoLoad');
use MesProduits\Produit;
$ordinateur = new Produit("ordinateur",10,1200,false);
echo $ordinateur . "<br>";
echo $ordinateur->supprimerProduit(5) . "<br>";
use MesProduits\ProduitParLots;
$cartouchesEncre=new ProduitParLots("Cartouches d'encre",3,50,false);
$cartouchesEncre->setNbArticlesParLot(10);
$cartouchesEncre->ajouterProduit(6);
echo $cartouchesEncre . "<br>";
Produit.php (parent class file)
namespace MesProduits; //donner le même nom que le dossier parent
class Produit{
protected $nom = "mon produit";
protected $quantite = 10;
protected $prix = 120;
protected $rupture = false;
function __construct($nom,$quantite,$prix,$rupture)
{
$this->nom=$nom;
$this->quantite=$quantite;
$this->prix=$prix;
$this->$rupture=$rupture;
}
function __toString(){
return "nom: " . $this->nom . "<br>".
"quantité: " . $this->quantite . "<br>".
"prix: " . $this->prix . "<br>".
(($this->rupture)? "no stock <br>" : "in stock <br>");
}
function ajouterProduit($quantite){ //parent method and I want the same name in the child file
$this->quantite+=$quantite;
if($this->quantite >=0){
$this->rupture = false;
}
return "a product has been add <br>" .
"there is: " . $this->quantite . " in stock <br>";
}
function supprimerProduit($quantite){
$this->quantite-=$quantite;
if($this->quantite <=0){
$this->rupture = true;
}
return "a product has been removed <br>" .
"there is " . $this->quantite . " in stock <br>";
}
}
ProduitParLots.php (child file class)
namespace MesProduits;
class ProduitParLots extends Produit{
private $nbArticlesParLot;
function getNbArticlesParLot(){
return $this->nbArticlesParLot;
}
function setNbArticlesParLot($valeur){
if(!is_integer($valeur)){
echo "the property must be an integer <br>";
}else{
$this->nbArticlesParLot=$valeur;
}
}
function ajouterProduit2(){ //need to choose a different name for the child method
$this->quantite+=$this->nbArticlesParLot;
if($this->quantite>0) $this->rupture=false;
}
}
This is because the "child" method has not the same signature as the parent method. You missed the $quantite parameter.
class ProduitParLots extends Produit
{
function ajouterProduit($quantite) { /* ... */ }
}

PHP array getting duplicate values

I am working on displaying information from my database. When I did print_r in the model/itemTile.php below to check on my array, $this->display, I noticed it had stored 2 copies of the data from my database. I checked my database, and there was definitely only one copy of the data.
I created a counter variable, $this->counter, to see what the surrounding while loop was doing. The original data had 6 non-duplicating rows. As you may see in the jpg attached below, the program increments and echo the counter to 6, then it does the "print_r($this->display)" line that is outside of the while loop, then for some strange reason goes back to the while loop, increment the counter, and print the $this->counter and $this->display again!
I can remove the duplicate, but I would much prefer to figure out why exactly there are two copies of the value to begin with.
Since this was originally a PHP class project that focus on MVC, everything is placed into controller, model, and view. I have included the relevant model and view code below:
Jpg:
PHP Site
model/itemTile.php
<?php
require_once('siteInfo.php');
class itemTile implements siteInfo {
private $term;
private $session;
private $result;
private $display = array();
private $counter = 0;
public function __construct($session) {
$this->session = $session;
}
public function getContent() {
$this->result = $this->session->db->prepare("SELECT productName, sciName, price FROM products");
$this->result->execute();
$this->result->bind_result($pN, $sN, $pz);
while ($this->result->fetch()) {
if (array_key_exists($pN, $this->display)) {
$this->display[$pN]["price"][] = $pz;
} else {
$this->display += [
$pN => [ //Product Name was used to id array because not all item have sciName,
"sciName" => [$sN], //and not all item have only 1 sku (1 item with different size = multiple pid).
"price" => [$pz]
]
];
}
$this->counter++;
echo $this->counter . "<br />";
}
$this->result->close();
print_r($this->display);
echo "<br />";
}
public function setContent() {
$this->getContent();
return $this->display;
}
}
?>
view/itemTile.php
<?php
class itemTileView {
private $model;
public function __construct(itemTile $model) {
$this->model = $model;
}
public function output(){
foreach ($this->model->setContent() as $item => $detail) {
$itemLink = preg_replace('/\s+/','_', $item);
echo "<div class= 'tileSpace'>";
echo "<a href='itemPages/" . $itemLink. "/home.php'>";
echo "<img alt='" . $item . "' src='itemPages/" . $itemLink . "/thumbnail.jpg' width='100' height='100'>";
echo "</a>";
echo "<p>" . $item . ": " . $detail["sciName"][0] . "</p>";
if (count($detail["price"]) > 1) {
echo "<p>" . min($detail["price"]). " - " . max($detail["price"]). "</p>";
} else {
echo "<p>" . $detail["price"][0] . "</p>";
}
echo "</div>";
}
}
}
?>
Can anyone spot where is the problem occurring?
use php function array_unique();
array_unique($arrayname);
using this you will get unique values from array.it avoids duplicate values

printing an variable of an object that's inside an array that's inside an object

Well, ive been trying to get my crm to print multiple contacts for each company but i cant get it to work
Company is a class,companycontactis a class
//class called company
function __construct($idklanten,$naam,$adres,$postcode,$stad,$contacten){
$this->idklanten=$idklanten;
$this->naam=$naam;
$this->adres=$adres;
$this->postcode=$postcode;
$this->stad=$stad;
$this->contacten=$contacten;
}
//class called contact
function __construct($idcontactklanten,$voornaam,$tussenvoegsel,$achternaam,$tel,$email,$klantID){
$this->idcontactklanten=$idcontactklanten;
$this->voornaam=$voornaam;
$this->tussenvoegsel=$tussenvoegsel;
$this->achternaam=$achternaam;
$this->tel=$tel;
$this->email=$email;
$this->klantID=$klantID;
}
//getname for a contact
function getNaam() {
if(strlen($this->gettussenvoegsel()) == 0) {
return $this->getvoornaam()." ".$this->getachternaam()."";
}
else {
return $this->getvoornaam() . " " . $this->gettussenvoegsel() . " " . $this->getachternaam();
}
}
//function for getting the names from my object company,array with objects of contacts
function getcontacten(){
$ct=$this->contacten[$teller];
$txt="";
for($teller=0;$teller<10;$teller++){
$txt+=$ct->getNaam()."<br>";
}
return $txt;
}
then on my index page when i call getcontacten() it does not work comparing to my other get function which do work. it just outputs a 0
Any help is appreciated
Your biggest error would be the following:
$txt+=$ct->getNaam()."<br>";
Should be
$txt.=$ct->getNaam()."<br>";
Because to append to a string you use ".=", not "+=".
Also I don't know if the other part of you code works, I would write something like the following:
$txt = "";
foreach ($this->contacten as $ct){
$txt .= $ct->getNaam() . "<br />";
}
return $txt;
or
$txt = "";
for ($i = 0; $i < count($this->contacten); $i++){
$txt .= $this->contacten[$i]->getNaam() . "<br />";
}
return $txt;

Understanding PHP Class OOP structure [closed]

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Closed 8 years ago.
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I'm trying to create a class function but somehow it won’t work and I can’t figure out what’s the problem. Is it the way I declare the variable or what so ever?
<?php
class Car{
var $model;
var $make;
var $speed;
function Car ( $model, $make, $speed)
{
$this->model = $model;
$this->make = $make;
$this->speed = $speed;
}
function accelerate ($speed)
{
$add = 5;
$speed = $speed + $add;
return $speed;
}
function get_status()
{
echo "Car status : \n";
echo "Model :" $this-> model "\n";
echo "Make :" $this-> make "\n\n";
}
function get_speed()
{
return $this->speed;
}
}
?>
<?php
$car1 = new Car();
$car1 -> get_status("Vios", "Toyota");
for( $i = 0; $i < 5 ; $i++)
{
echo "Accelerating... <br> \n";
echo "Current speed : accelerate(5) km/h <br>";
}
?>
Lots of issues with your code. But at least this cleaned up version should work without the script dying completely. Here is a breakdown of what I did:
Set the variables that were set as var to public since that is the preferred method of setting variables.
In function Car, I set default values for $model, $make & $speed so if they are not passed—like in your example—there is at least a default value to act on.
Your echo lines in get_status did not have the . for concatenation so they were not properly concatenating the strings.
Then you setting $this-> make and $this-> model with empty spaces is syntactically incorrect. So set those to $this->make and $this->model.
Then when you are calling the class, you set this "Current speed : accelerate(5) km/h <br>"; which is syntactically incorrect as well. So set that to echo "Current speed : " . $car1->accelerate(5) . " km/h <br>"; so it can actually echo values.
But that said, unclear on what the output is for this code. The logic is a bit of a mess. But at least it’s not completely dying like it did before!
And here is the cleaned up code:
class Car {
public $model;
public $make;
public $speed;
function Car ($model = 0, $make = 0, $speed = 0) {
$this->model = $model;
$this->make = $make;
$this->speed = $speed;
}
function accelerate ($speed) {
$add = 5;
$speed = $speed + $add;
return $speed;
}
function get_status () {
echo "Car status : \n";
echo "Model :" . $this->model . "\n";
echo "Make :" . $this->make . "\n\n";
}
function get_speed () {
return $this->speed;
}
}
$car1 = new Car();
$car1->get_status("Vios", "Toyota");
for( $i = 0; $i < 5 ; $i++) {
echo "Accelerating... <br> \n";
echo "Current speed : " . $car1->accelerate(5) . " km/h <br>";
}
And—like I said before—since the way you are calling the class makes little sense to the structure you have, I slightly reworked the code above so it loops through an array of car values like this:
$car_array = array("Vios", "Toyota");
foreach ($car_array as $car_value) {
$car1 = new Car($car_value);
$car1->get_status();
for( $i = 0; $i < 5 ; $i++) {
echo "Accelerating... <br> \n";
echo "Current speed : " . $car1->accelerate(5) . " km/h <br>";
}
}
Add a constructor like this:
public function __construct($model = 0, $make = 0, $speed = 0) {
$this->model = $model;
$this->make = $make;
$this->speed = $speed;
}
http://us3.php.net/manual/en/language.oop5.decon.php
When concatenating strings, you must use the dot operator:
echo "abcd" . "efgh";

Accessing a variable in the function declared in model from the controller in Zend framework

I am quite new to OOPS and Zend. I am converting a part of web app code to Zend framework, I can't post all the code in here coz its quite lengthy. I created a model as in the code below(I can post only two functions) and I want to access the variables inside the functions from the controller and then print them out in HTML tables(I guess I will have to use "views" for that", below is my model:
public function getVenueTypes()
{
$poiTypes = array();
if($this->_cache)
{
$key = $this->getCacheKey()."poiTypes_stats:{$this->language}";
}
if(!$poiTypes)
{
$sql = "SELECT poi_type_id, poi_type_name_".$this->language."
AS
poi_type_name
FROM
poi_types
ORDER BY
poi_type_name_".$this->language." ASC";
$result = mysql_query($sql);
if(!$result)
{
$message = 'Invalid query: ' . mysql_error() . "\n";
$message .= "Whole query: \n\n$sql\n";
die($message);
}
while($row = mysql_fetch_array($result))
{
$poiTypes[] = array('id' => $row['poi_type_id'] ,'name' => $row['poi_type_name']);
}
print_r($poiTypes);
if ($this->_cache)
{
$this->_cache->save($key, $poiTypes);
}
}
foreach($poiTypes as $poiType)
{
$count_type = null;
if($this->_cache)
{
$key = $this->getCacheKey()."poiTypeCount:{$poiType['id']}:{$this->metro_id}";
$count_type = $this->_cache->load($key);
}
if(!$count_type)
{
$sql = "SELECT COUNT(*) FROM
poi
WHERE
find_in_set('{$poiType['id']}', poi_type_id_array)
AND poi_status = 1 AND poi_address_prefecture_id = '$this->metro_id'";
$result = mysql_query($sql) or die(mysql_error());
}
if(!$result)
{
$message = 'Invalid query: ' . mysql_error() . "\n";
$message .= "Whole query: \n\n$sql\n";
die($message);
}
while($count = mysql_fetch_array($result))
{
$count_type[$poiType['id']][$this->metro_id] = $count['COUNT(*)'];
}
if($this->_cache)
{
$this->_cache->save($key, $count_type);
}
}
}
Any help is Highly appreciated, I hope I am being clear enough and thanks in advance.
I'm noy sure if this will help you, but you have several options to access those values.
Option 1: return an array with the variables you need
return array($myVar1, $myVar2, ..., $myVarN);
Option 2 (less modular): create the html string inside that function and then echo or return the string.
Im assuming that you have a basic knowledge of Zend
The basic idea of Zend framework is the link between controller ,models and view
Your model file,BlaBla.php
Class Namespace_models_BlaBla extends Zend_Db_Table_Abstract{
public function foo(){
return 'hello world';
}
}
Your controller say BarController and an action say test
class BarController extends extends Zend_Controller_Action{
public function testAction(){
$class = new Namespace_models_BlaBla();
$this->view->string = $class->foo();
}
}
Your html side // test.phtml
<?php echo $this->string; ?> /**this will output hello world **/

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