I am new to PHP generally and caching and am trying to develop a Facebook share counter for Wordpress. As advised by a member here, since it's not optimum to make calls to the API and slow down the website each time, I decided to cache the results and went with the static method. Here's the code I am using.
function fb_cache($atts) {
$url = $atts['url'];
static $fb_cache = array();
if (isset($fb_cache[$url])) {
$fb_count = $fb_cache[$url];
return $fb_count;
} else {
$fb = json_decode( file_get_contents('http://graph.facebook.com/' . $url) );
$fb_count = $fb->share->share_count;
$fb_cache[$url] = $fb_count;
return $fb_count;
}
}
This doesn't seem to work as the number keeps changing every few seconds and the API calls are thus being made each time. To use it as a plugin, I also have an instantiating code in the end.
static function get_instance() {
static $instance = false;
if ( ! $instance ) {
$instance = new self;
}
}
Can someone tell me what I am doing wrong. I apologize if it's a noob question and if I am using the wrong method altogether.
Related
I'm trying to use zookeeper in a php app, and I've done most of the get($path)/set($path, $value)/getChildren($path) functions following https://github.com/andreiz/php-zookeeper, except the watch_callback function that just doesn't work.
My php version is 5.6.14 and thread safety disabled, and I'm using apache2.4.
Here is some code snippet
class Zookeeper_Module {
private $zookeeper;
public function __construct(){
$this->ci = & get_instance();
$zookeeper_server = $this->ci->config->item('zookeeper_server');
$this->zookeeper = new Zookeeper($zookeeper_server);
}
public function set($path, $value){
$this->zookeeper->set($path, $value);
}
public function get($path, $watch_cb = null){
return $this->zookeeper->get($path, $watch_cb);
}
public function get_watch_cb($event_type = '', $stat = '', $path = ''){
error_log('hello from get_watcher_cb');
$value = $this->get($path, array($this, 'get_watch_cb'));
// update redis cache
$this->ci->cache->redis->save('some cache key', $value);
}
}
class MyTest{
public function get(){
$zookeeper = new Zookeeper_Module ();
$value = $zookeeper->get( '/foo/bar', array (
$zookeeper,
'get_watch_cb'
) );
}
public function set(){
$zookeeper = new Zookeeper_Module ();
$zookeeper->set( '/foo/bar', 'some value');
}
}
I can successfully get or set a node value, but I can neither catch watch callback log nor have redis cache updated.
I write a more simple demo, very similar with this https://github.com/andreiz/php-zookeeper/wiki, and the watcher works fine in this demo.
The most significant difference is
while( true ) {
echo '.';
sleep(2);
}
While java has a jvm container hosting watchers, php doesn't has a container to do it, so we have to use a while(true) to keep watchers alive.
So I add a while(true) in my code and now the watcher works fine.
But I don't want to add a terrible while(true) in a web app, so the final solution is adding a java app to communicate with zookeeper and save results in redis, and php app just reads info from redis.
So i have the following code:
private function getArtistInfo($artist){
$artisan = json_decode($artist, true);
$artistObj = array();
//fb($artist);
$artistObj['id'] = $artisan['name']['ids']['nameId'];
$memcache = new Memcached($artistObj['id']);
$artistCache = $memcache->getMemcache();
if($artistCache === false){
$artistObj['name'] = $artisan['name']['name'];
$artistObj['image'] = $artisan['name']['images'][0]['url'];
$initArtist = array('id' => $artistObj['id'], 'name' => $artistObj['name'], 'image' => $artistObj['image']);
$artistObj = $this->buildArtist($artisan, $artistObj);
$memcache->setMemcache($artistObj);
}
else{
$initArtist = array('id' => $artistCache['id'], 'name' => $artistCache['name'], 'image' => $artistCache['image']);
}
return $initArtist;
}
Now the code works but it takes getArtistInfo() too long to finish when i just want the $initArtist value; I would like my client to get right away the $initArtist once its constructed, and somehow let the caching of $artistObj runs in the background.
So far i have read up on several different topic i thought might be useful: event delegation, callback function, call_user_func, observer pattern, threading, gearman etc. However, I have no idea which one of them would actually do what i want. Please point me to the right direction.
EDIT:
My Memcached class:
class Memcached {
private static $MEMCACHED_HOST = "localhost";
private static $MEMCACHED_PORT = "11211";
private $id, $key, $memcache, $cacheOK;
function __construct ($id){
$this->id = $id;
$this->key = 'artistID_'. $this->id;
$this->memcache = new Memcache;
$this->cacheOK = $this->memcache->connect(Memcached::$MEMCACHED_HOST, Memcached::$MEMCACHED_PORT);
}
protected function getMemcache(){
$artistInfo = null;
if($this->cacheOK === true){
$artistInfo = $this->memcache->get($this->key);
}
if($artistInfo === false){
return false;
}
return $artistInfo;
}
public function setMemcache($artistInfo){
$this->memcache->set($this->key, $artistInfo, 0, 60);
}
}
My buildArtist() code:
private function buildArtist($artisan, $artistObj){
$artistObj['amgID'] = $artisan['name']['ids']['amgPopId'];
$discography = $artisan['name']['discography'];
foreach($discography as $album){
$albumID = $album['ids']['amgPopId'];
preg_match('/(\d+)/', $albumID, $matches);
$albumObj['amgAlbumID'] = $matches[1];
$albumObj['title'] = $album['title'];
$albumObj['releaseDate'] = $album['year'];
$albumObj['more'] = $this->getMoreMusic($albumObj['title'], $artistObj['name']);
$artistObj['discography'][] = $albumObj;
}
return $artistObj;
}
Well, it's not entirely clearly how long too long is, or which part of this code is what's slowing you down. For all we know, the slow part isn't the part that stores the data in Memcached.
In any case, once you do identify that this is your bottleneck, one thing you can do to accomplish this type of out of order execution is use a brokerless messaging queue like ZeroMQ to accept JSON object that need cached. A separate PHP script can then take on the job of processing and caching these requests asynchronously outside of any web-request. This separate script could be run through a cron-job or some other job manager that handles the caching part in parallel.
You want to use set and get rather than using the memcache persistence ID, i'm not even sure what setMemcache and getMemcache are but they aren't in the extension documentation.
Here's an example from the documentation:
<?php
$m = new Memcached();
$m->addServer('localhost', 11211);
if (!($ip = $m->get('ip_block'))) {
if ($m->getResultCode() == Memcached::RES_NOTFOUND) {
$ip = array();
$m->set('ip_block', $ip);
} else {
/* log error */
/* ... */
}
}
Please show the code of buildArtist for help on optimizing it.
I have a php file that previously used to write xml data with tags. Now I'm trying to make it a little remoteobject based. So instead of writing xml I'm trying to return a class object that consists some big multidimensional array. The problem is it is causing a high latency. I'm not sure if it's my php file that is causing latency problem.
My php code :
class output{
public $grid;
public $week;
public $name;
var $_explicitType = "org.test.output";
}
class manager1{
function init($params,$arrayOut)
{
$action = $params[0];
switch ($action)
{
case "reload": return $this->Reload($arrayOut);break;
default:return $this->form($arrayOut);
}
}
private function Reload($arrayOut)
{
$this->getSlice();
$arrayOut->grid = $this->gridValue();
$arrayOut->week = 'no data';
return $arrayOut;
}
private function form($arrayOut)
{
$arrayOut->grid = $this->gridValue();
$arrayOut->week= $this->getAllWeek($this->ThisYear);
return $arrayOut;
}
}
AS-3 code calling php function:
private function init():void{
var _amf:RemoteObject = new RemoteObject();
var params:Array = new Array(); //parameters array
params.push("default");
var arrayOut:output = new output();//strongly typed class
_amf.destination = "dummyDestination";
_amf.endpoint = "http://insight2.ultralysis.com/Amfhp/Amfphp/"; //amfphp home directory
_amf.source = "manager1"; //the php class which will be called
_amf.addEventListener(ResultEvent.Result, handleResult);
_amf.init(params,arrayOut);
}
private function handleResult(event:ResultEvent):void
{
datagrid.dataProvider = event.result.grid;
}
And there is also a class named output in my application:
package org.test{
public class output
{
public var grid:Array;
public var week:Array;
}
}
I'm using this to pass value to flex remoteobject using amfphp.
Actually, it's fairly easy to figure out.
You can use the Network Monitor that is part of Flash Builder. It shows the Request Time and the Response Time, so you can get a pretty good idea if the issue is with the PHP side or the Flex side. You can also see the size of the response.
Be aware that Remote Objects mixed with Multidimentional arrays can be larger than you think, but again the Network Monitor will help you figure out that.
I'm experimenting with php mvc and I'm stucked with the following issue. My request and router classes are really simple and I would like to extend theme to can handle controller calls from sub folders and to controller classes functions should be able to pick up url variables send it threw get and post.
my router looks as it follows
class Router{
public static function route(Request $request){
$controller = $request->getController().'Controller';
$method = $request->getMethod();
$args = $request->getArgs();
$controllerFile = __SITE_PATH.'/controllers/'.$controller.'.php';
if(is_readable($controllerFile)){
require_once $controllerFile;
$controller = new $controller;
if(!empty($args)){
call_user_func_array(array($controller,$method),$args);
}else{
call_user_func(array($controller,$method));
}
return;
}
throw new Exception('404 - '.$request->getController().'--Controller not found');
}
}
and Request class
private $_controller;
private $_method;
private $_args;
public function __construct(){
$parts = explode('/',$_SERVER['REQUEST_URI']);
$this->_controller = ($c = array_shift($parts))? $c: 'index';
$this->_method = ($c = array_shift($parts))? $c: 'index';
$this->_args = (isset($parts[0])) ? $parts : array();
}
public function getController(){
return $this->_controller;
}
public function getMethod(){
return $this->_method;
}
public function getArgs(){
return $this->_args;
}
}
The problem is:when I try to send threw ajax, variables to a controller method this are not recognized because of its url structure.
For example
index/ajax?mod_title=shop+marks&domain=example
is accepted just if it look
index/ajax/shop+mark/example
Your code contains what is known as an LFI vulnerability and is dangerous in its current state.
You should whitelist your what can be used as your $controller, as otherwise an attacker could try to specify something using NUL bytes and possibly going up a directory to include files that SHOULD NOT be ever included, such as /etc/passwd, a config file, whatever.
Your router is not safe for use; beware!
edit: example on whitelisting
$safe = array(
'ajax',
'somecontroller',
'foo',
'bar',
);
if(!in_array($this->_controller, $safe))
{
throw new Exception(); // replace me with your own error 404 stuff
}
Since your Request class uses a URI segments approach for identifying controller, action and arguments, global variables such as $_GET or $_REQUEST are not taken into account from within your Request.
What you need to do is to make some additions to your Request code. Specifically:
Remove the line:
$this->_args = (isset($parts[0])) ? $parts : array();
And add the following:
$all_parts = (isset($parts[0])) ? $parts : array();
$all_parts['get'] = $_GET;
$this->_args = $all_parts;
This way, $_GET (ie variables passed via the url) variables will be available in the actions called, as they will be in $args (they will be available as $args['get'] actually, which is the array that holds the $_GET vars, so you will be able to have access to domain=example by using $args['get']['domain']).
Ofcourse, you can add one more method in your Request class (e.g. query) that might look like that:
public function query($var = null)
{
if ($var === null)
{
return $_GET;
}
if ( ! isset($_GET[$var]) )
{
return FALSE;
}
return $_GET[$var];
}
This way, you can get a single variable from the url (e.g. $request->query('domain')) or the whole $_GET array ($request->query()).
That's because php will put "?mod_title=..." in the $_GET array automatically. Your getArgs() function should check for $_GET, $_POST or $_REQUEST.
If you're trying for a minimal MVC approach, have a look at rasmus' example: http://toys.lerdorf.com/archives/38-The-no-framework-PHP-MVC-framework.html
If your use case is going to get more complex, have a look at how Zend (http://framework.zend.com/manual/en/zend.controller.html) or Symfony (https://github.com/symfony/symfony/tree/master/src/Symfony/Component/Routing) do their stuff.
Choose any popular MVC to see how they implement it under the hood. In addition, spl_autoload_register and namespace are your friends.
What would be a good way (along with any pros and cons) of initializing an instance of a PHP class with another object of the same class (ideally in PHP 4.x)?
Here in initialize() is essentially what I'd like to be able to do (example is extremely simplified from my use-case, see below):
$product = new Product('Widget');
$product2 = new Product('Widget #2');
$product->initialize($product2);
echo $product->name; // echos "Widget #2"
class Product {
var $name;
function __constructor($name) {
$this->name = $name;
}
function initialize($product) {
// I know this cannot be done this way in PHP.
// What are the alternatives and their pros & cons?
$this = $product;
}
}
I know this may not be "good programming practice"; with 20+ years programming experience on other languages I know a bit about what's good and what's not. So hopefully we won't get hung up on if doing this makes sense or not. I have a use-case working with some open-source code that I can't change so please just bear with me on my need for it. I'm actually trying to create an OOP wrapper around some really ugly array code buried deep in the core of WordPress.
I'm trying to write it so in future versions they can move away from the ugly array-based code because everyone will be using the new API that otherwise fully encapsulated these nasty arrays. But to make it work elegantly I need to be able to do the above (in PHP 4.x) and I don't want to write code that just copies the properties.
Thanks in advance for your help.
UPDATE
Many of you are suggesting clone but unless I misunderstand that doesn't address the question. clone makes a copy; that's not the crux of the question. I'm instead trying to get the constructed object to "become" the object passed in. At this point I'm assuming there isn't a way to do that based on the fact that 0 out of 5 answers have suggested anything but I'll wait a bit longer before selecting a best in case it was simply that my questions was unclear.
In PHP 5, object cloning might be more relevant:
http://php.net/manual/en/language.oop5.cloning.php
You can define a special __clone method.
In PHP 4 and 5, you can copy properties via:
function copy($obj)
{
foreach (get_object_vars($obj) as $key => $val)
{
$this->$key = $val;
}
}
However, you wrote "I don't want to write code that just copies the properties," and I'm not exactly sure what you mean by that.
Preferred way of doing this is to use clone keyword and to implement appropriate __clone() method if needed as mentioned by other posters. Another trick way of doing this (con: slow, pros: can be stored, sent over network and works identical in php4/5) is to serialize an object and then unserialize to create new copies of it with identical variable values.
Example:
$productCopy = unserialize(serialize($product));
EDIT: Sorry, misunderstood what you were asking for. You will have to initialize variables of the object being constructed with passed in object's variables inside of the constructor. You can't return a reference to another object from the constructor.
Example:
public function __construct($name, $object = null) {
if($object) {
foreach(get_object_vars($object) as $k => $v) {
$this->$k = $v;
}
} else {
$this->name = $name;
}
}
class Product {
var $name;
function __construct($value) {
if (is_a($value, 'Product')) {
$this->name = $value->name;
} else {
$this->name = $value;
}
}
}
Similarly, you can use instanceof instead of is_a if you prefer (depending on your PHP version).
Now you can pass a Product instance OR a name to the construct.
$product = new Product('Something');
$clone = new Product($product);
This is the best way of doing it so far:
http://www.blrf.net/howto/51_PHP__How_to_control_object_instances_in_PHP_.html
Don't use "new", instead use a static function that returns the instance you want.
I have done the following:
class MyClass {
private static $_instances;
public static function get($id) {
if (!self::$_instances) self::$_instances = Array();
$class = get_called_class();
if (!array_key_exists($class, self::$_instances)) self::$_instances[$class] = Array();
if (!is_numeric($id) || $id == '') throw new Exception('Cannot instantiate a non-numeric ID.');
if (array_key_exists($id, self::$_instances[$class])) return self::$_instances[$class][$id];
else {
self::$_instances[$class][$id] = new static($id);
return self::$_instances[$class][$id];
}
}
function __construct($id=false) {
// new instance code...
// I use $id=false to create new a db table row not load an old one
}
}
Usage:
// New instance
$a = new MyClass();
$a = new MyClass;
// MyClass with $id = 1
$b = MyClass::get(1);
$c = MyClass::get(1);
$d = new MyClass(1);
$b and $c point to the same object, while $d is a new one.
Caveats:
Garbage collection will no longer apply as your instances are stored in a static array
You'll have to change your code to use MyClass::get
Notes in my code:
New instances are called with "new static" instead of "new self" to use late static bindings.
You can set your constructor to private. This will break all your old code if you use "new", but will ensure you don't get double instances or more. You'll have to change a bit in the get function's arguments and code to allow $id=false or $id=-1 or whatever.
maybe
$product = new Product('Widget');
$product2 = new Product(null, $product);
echo $product2->name; // echos "Widget #2"
class Product {
var $name;
function __constructor($name, $product = null) {
$this->name = !empty($name) ? $name : $product->name;
}
}
Adding another answer due to it being radically different.
$product = new Product('Widget');
$product2 = new Product('Widget #2');
$product =& $product2;
echo $product->name; // echos "Widget #2"
That should work.