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PHP - How To Communicate Back And Forwards Between Classes?
Ive always had a bit of trouble with php and effectively talking between classes, as the example below shows I want to call a first class->function that will later call a different class and its function then call the previous class again. I havent been able to find any examples that state how to do this if possible.
Code: [Select] <?php class A{ function b(){ //does required code etc... $B = new B(); $B->BA(): } function AB(){ echo "I WANT TO END UP HERE, from class B function BA"; } } class B{ function BA(){ //does required code etc... // //Unsure how to call class/function A->AB } } $a = new A(); $a->AB(); ?> Is this possible as it helps separate my code in to nice and easy to read Thanks Similar TutorialsHello, I have a problem with writing a function that will display the number of attempts to communicate with the host that have not been answered, if the host starts responding again, the table should display, for example 0. The website addresses are taken from the MySQL database. The next column should display the time from which the communication with the host was lost and if it responds, it should display, e.g. OK. Please, give me some hints how to write it. Thanks in advance. Edited October 12, 2019 by xyz91I've been spending long hours learning about classes and their magic methods. I just came across a tutorial which showed a constructor like this:
class Device {
//...
public function __construct(Battery $battery, $name) {
// $battery can only be a valid Battery object
$this->battery = $battery;
$this->name = $name;
// connect to the network
$this->connect();
}
//...
}
the Battery part instantly caught my attention. Here had previously made a Battery class (and a more complete Device class) but the next thing he did really caught my interest:
$device = new Device(new Battery(), 'iMagic'); // iMagic connected echo $device->name; // iMagicwhat the hell is going on here? Is this another way to include the methods and properties of one class into another class, in order words is this the same thing as: class Device extends BatteryI don't think so because this new Battery() thing looks more like its creating an object inside the Device object. Previously the only way I could to that was to type $battery = new Battery() inside one of my methods. But this looks like hes doing something different. Can anyone explain whats going on here? The whole tutorial is he http://code.tutsplus...-php--net-13085 in the main Device method he has a premade $battery variable to hold the Battery object. Sometimes I have multiple classes containing functions which I'd like to include in my main class. I can only extend one class, so I usually extent a class containing only properties, no methods. I still don't know what difference making that info class abstract is, I'd appreciate if anyone could tell me. Also I'd love to know what the point in static methods is. I've never used them because I've never seen the point. Is it just to make it easier to call the methods because you don't need to create an object instance to call them? Sorry for the extra questions, the first one is what I'm really wondering about. Please, take a look to the following code.After clicking Next it goes to overview.php.Why when I click back on my browser to return to this page again, it is not returning back? When I click back I receive "Confirm Form Resubmission" message. After refreshing page it loads page. I guess problem is in "session_start();" part. Something to do with cookies. Please, help me it is very urgent for me. <?php session_start(); echo "<html> <head> <title>Hello World</title> <meta http-equiv='Content-Type' content='text/html; charset=Windows-1252'/> </head>"; require_once ('functions.inc'); if(!isset($_POST['userid'])) { echo "<script type='text/javascript'>"; echo "window.location = 'index.php'"; echo "</script>"; exit; }else{ session_register("userid", "userpassword"); $username = auth_user($_POST['userid'], $_POST['userpassword']); if(!$username) { $PHP_SELF = $_SERVER['PHP_SELF']; session_unregister("userid"); session_unregister("userpassword"); echo "Authentication failed " . "Please, write correct username or password. " . "try again "; echo "<A HREF=\"index.php\">Login</A><BR>"; exit; } } function auth_user($userid, $userpassword){ global $default_dbname, $user_tablename; $user_tablename = 'user'; $link_id = db_connect($default_dbname); mysql_select_db("d12826", $link_id); $query = "SELECT username FROM $user_tablename WHERE username = '$userid' AND password = '$userpassword'"; $result = mysql_query($query) or die(mysql_error()); if(!mysql_num_rows($result)){ return 0; }else{ $query_data = mysql_fetch_row($result); return $query_data[0]; } } echo "hello"; echo "<form method='POST' name='myform' action='overview.php'>"; echo "<input type='submit' value='Next'>"; echo "</form>"; ?> Not sure how to describe what I'm trying to do here in the title, but here goes with what I am trying to accomplish. I've got a few hundred lines of code in total so far, so I'll try to keep it as short as I can. I've got an application that I am programming using classes for each module and right now I am coding the base classes that I need in order for it to run (database, errors, logging, etc). What I'm doing for my database class is I have a query factory and it extends the MySQLi class so I can process, clean and code the rest of my app faster. I also have another, unrelated class "Error", which will be used for processing errors I might come across. I'd rather do it this way instead of having to call trigger_error and error_log every time there is an error. I'd also not like to have to call a new instance of an object every time I need to use something from that class. Is there any way I can call a class within a class and return it as an object for all the methods within the class? I've tried the methods below, but no luck I've tried others, but I'm trying to keep it brief and get what I'm trying to do across. <?php class QueryFactory extends MySQLi { public $err = new error(); //Doesn't work. public $err = error(); //Nope. #This is the function that I need the $err object for. function set($fields, $newvals) { if ( is_array($fields) && is_array($newvals) ) { if ( count($fields) != count($newvals) ) { //Instead of below, I want to do something like $err->('Array lengths must match for method', 256, $islogged = 1); trigger_error('Array lengths must match for method', 256); } } } } The thing is, I have a "run.inc.php" which does include and create new objects for running just the basic app and if I try to redeclare the error class in query.class.php, it gives me an error saying I can't do that, but if i try to call $err from the page that has all the classes defined it throws an error saying that my method is undeclared. I'd like my error class be available to every other class I create so I can display and log errors as needed. Any suggestions or links to point me where I'd like to go? ini_set('display_errors', 1); error_reporting(E_ALL); class A { private function operation1() //only be used inside this class { echo 'operation1 called'; } protected function operation2() //only inside this class { echo 'operation2 called'; } public function operation3() //public can be used in any class { echo 'operation3 called'; } } class B extends A { function _construct() { //$this->operation1(); //$this ->operation2(); $this->operation3(); } } $b = new B; can someone please tell me why this code doesn't work ? Hi there,
This might a newbie question but I need help understanding PHP classes which am currently learning.
I have an index page.
With this three included files.
database.php
config.php
account.php
on database.php, the class is declared using $connection new Database(...), on this page is also all the coding for this class.
In config.php is a declared class of $account new Account($user_id);
and on account.php is all the details for the account class.
on the index.php is echo $account->sayHello;
However, My page is throwing out an error because I'm trying to use $connection->query(..) in my account.php / Account class.
I have tried to extend the Account class with Database but still have no luck.
How can I make sure the I can use a class function from another page in my Account class?
Thanks for reading
If I have defined an instance of a class in one script how do I then use this same instance and the same variable in other scripts? For example say I have this code in a file called "index.php" include("myclass.class.php"); $myclass = new myClass; $myclass->$variable = "hello world"; However if I then have this code in a file called "page1.php" when I try to access the same variable it is empty. include("myclass.class.php"); echo($myclass->$variable) How can I use the same instance of this class across all files keep the variable values the same? Thanks for any help. How can i get my class to be showed on the front page here is the front page <?php require('ex2.php'); $start = new A(); $tart->Display(); ?> now here is ex2.php <?php ini_set('display_errors', 1); error_reporting(E_ALL); class A { public $title = "test1"; public $end = "test2"; } function __set($name, $value) { $this->$name = $value; } function Display() { echo $title; echo $end; } ?> shoudn't this print test1 and test2 ? Take the following example: <?php class a { var $things; public function __construct($stuff) { $this->things = $stuff; } } class b { var $morethings; $this->morethings = "something"; } $c = new a(new b); echo $c->things->__PARENT__; ?> The line "echo $c->things->__PARENT__;" (as you can probably imagine) does not work. How would I output what the 'b' object is stored in ('a')? Hello All, I am fairly new to PHP class development, and I was wondering if it is normal behaviour to see classes not being able to access global variables related to PHP-based requests ($_GET, $_SESSION, etc.)? I seem to either have to use "global <var>" inside of the class to access the data, or I am forced to change the methods so then such required data is passed in as parameters. Perhaps I am just doing something wrong? Here is an example of what I mean: class Something { function aFunc() { if (isset($_SESSION['somedata'])) { return false; } // this always returns false whether I had set the value or not } function bFunc() { global $_SESSION; // figured this would already be in a global accessible scope if (isset($_SESSION['somedata'])) { return false; } // now this will return false only when the value is set } } Now the above example is commented to demonstrate what I was meaning above, and I was wondering if this was the 'norm' when developing classes for PHP (and thus such values should be passed as parameters)? Thanks! Hi, I want to build a simple calculator class and one of the function is to calculate the factorial, but for some reason I cannot get this to work. Here is class: ========= Code: [Select] <?php class Calculator { function factorial($n) { if($n==1) return 1; else return factorial($n-1)*$n; } }//END CLASS Calculator $calculator=new Calculator(); print $calculator->factorial(3); ?> But it doesn't work, I know this is simple but I am a little rusty with object oriented programming. I'd appreciated any help! Hello, maybe back to basics, but [PHP] pobierz, plaintext Hi. I want to know how I access calsses in PHP. I mean how I search for class that I want and need. do I need to search in php.net? and what editors that provide access the the whole php classes and who they keep updated? Cheers. I have just start using PHP classes and was wondering how you continue an instance of a class in another file. For example I have a folder called "includes" where I includes files that I send data to when I perform ajax request. However how do I continue an instance of class in these files? Hope that makes sense. Thanks for any help. im currently doing a large php project and i am confident i can do it. Its a basic forum like phpbb or mybb where users can download the files and instal. however i have looked through their code and i see they use classes. I have never learned to do classes since i havent had to use them yet. should i be using them now for this project? do i need to? and if so then what are the benefits? hi, i would like to find out if anyone has any examples of code for a collection class(alternative to array) thanks I am not sure how to explain this, so I have some examples to go along. So This is how classes are normally laid out (from everything I have seen). Code: [Select] Base Class / \ Class A Class B You initiate class A or class B and inherits the base class functionality along with it. What I would like to do is something like this: Code: [Select] Base Class / \ Class A Class B \ / Root Class I would like to initiate the Root Class, and it inherits functionality from class A and class B and the base class. Here are my thoughts: You create an instance of the root class, this wouldn't do much other than tie everything together. Class A and B would have many similar functions such as process(), refund(), etc. (this whole ordeal is for credit cards, were going to be using 2 Gateways). So basically the root class will decide which gateway to use, were going to do 50/50 using mt_rand() for now, this would be in the root class. Then we call Class A or B which would be able to use functions from the base class such as getting the card from the database, decoding the hashed cc number value back to a valid cc number, etc. How should I make something like this? Thanks! hello, all i am trying to learn php, and currently trying to get my head around using classes. i have the following layout: index.php Code: [Select] <?php include("config/autoloader.php"); $content = new content(); $content->get_content(); // loads Content! $content->edit_content(); // Edits Content! ?> <?php $navbars = new navbars(); $navbars->get_navbar1(); // loads navbar1! ?> config/autoloader.php Code: [Select] <?php function spl_register_autoload($content) { include_once("classes/" . $content . ".php"); } function spl_register_autoload($navbars) { include_once("classes/" . $navbars . ".php"); } ?> content.php (content class file) Code: [Select] <?php class content { public function get_content() { echo "Show me the content!"; } public function edit_content() { echo "Edit the content"; } } ?> navbars.php navbars class file Code: [Select] <?php class navbars { public function get_navbar1() { echo "Show me the navbar1!"; } } ?> i keep getting the 500 - internal error on iis, but works on a single class file, as soon as i add more then one i get the error, can someone please help me and explain where i have gone wrong. thanks, all. I am working on my Pool class (base) and my FootballPool class (derived). I have this as my constructor Pool.php protected $pid, $uid, $pkid, $name; function __construct($pid, $uid){ $this->pid = $pid; $this->uid = $uid; $this->pkid = $this->pkid(); if(isset($_SESSION['picksInfo']['name'])) $this->name = $_SESSION['picksInfo']['name']; else $this->name = NULL; } Now a function in my FootballPool class needs to call $pid, $uid, and $pkid. How can I do that? I have tried this: Pool::$pid, but then I get this error Quote Fatal error: Access to undeclared static property: Pool::$pid in /var/www/core/includes/FootballPool.php on line 31 I am confused, because in the parents constructor, it is set. So basically, how can I call a variable set in the base class from a child or derived class? |
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