PHP - Does A Class's Constructor Run When I Call A Static Method From Outside The Class?

Hi people!

class FirstOne{

public function FunctionOne($FirstInput){
//do stuff and output value
return $value1;
}

}


Then:-


class SecondOne{

public function FunctionTwo($AnotherInput){
//do stuff and output value
return $value2;
}

}


What I want to know is this, if I want to use FunctionOne() in Class SecondOne do I do it like this:-

(Assume as I have instantiated the first class using $Test = new FirstOne(); )


class SecondOne{

function SecondedFunction(){
global $Test;
return $Test->FunctionOne();
}

public function FunctionTwo($AnotherInput){
//do stuff and output value
return $value2;
}

public function FunctionThree(){

//some code here
$this->Test->SecondedFunction();<--I think as I can omit the $this-> reference
}
}


My point is: Do I have to do it this way or is there way of having this done through __construct() that would negate the need for a third party function?

I have a version working, I just think that it is a little convoluted in the way as I have done it, so I thought I would ask you guys.

Any help/advice is appreciated.

Cheers
Rw

Hi, I need some help with php using class and constructor, this is stuff I am familiar with with Java but not in PHP, so I can't get the code to run.

please see code below:
================
Code: [Select]
<?php
$array1=array("");
$array2=array("");
$binary=1;

class Foobar {

/*Toy FCN that will append "dog" to 1 and "cat" to -1*/
//param numRuns is how many times to run this FCN


function putInProperArray($numRuns) {
for($i=0;$i<$numRuns;$i++) {
if($binary==1) 
$array1=$array1." dog <br />";
else if($binary==-1)
$array2=$array2." cat <br />";
$binary*=-1;
}
}

$fooBar=new Foobar();
$fooBar->putInProperArray(3);

}

?>

I just want it to store appended "dog" or "cat" string to array1 or array2, just a random function I made up. Please help, thanks.

I am calling my class constructor with the following code
class controller{
function _construct($name,$pass){
 session_start();
 get_model_class($name, $pass);
 echo "I\'m in controller";

}
} 
function get_model_class($username, $password){
$my_model = new  model();  
$my_model->check_users($username,$password);
}


$username = $_POST['username'];
$password = $_POST['password'];
echo "in controller.php";
$newUser = new controller($username,$password);

but it is not entering the constructor

So I have this class:

Code: [Select]
<?php
class page
{
private $title;
 
  function __construct(){

//note: This code snippet (below) does not appear to be having the desired effect of 
//running the PHP code on page declared by p
 
 if(!isset($_GET['p'])) :
        include("../content/home.php");
        else : 
        include("../content/{$_GET['p']}.php");
        endif;
///////////////////////////////////////////////
}

public function setTitle($t) {
$this->title=$t;
}?>

and I need the following from the content page (the page declared by $_GET['p']) to be ran in the constructor:

Code: [Select]
<?php 
global $page; 
$page->setTitle("About Us");
?>

this is in order to set the page title, so I can use it elsewhere.

I hope my explanation (although fairly vague), is somewhat clear.


Any help on this?  I was told that using <<<EOF would be a potential requirement? but I am completely unfamiliar with that method.

Long story short, I have a class that does some data verification and session management.  In order to do some of this verification, it needs a database connection.  I am using the MDB2 class;

here is a sample of the constructor's code:


this is a snippet of code from My Class.




// FUNCTIONS
function __construct() {

/*

other code here 

*/
// set up our datbase connection
global $dsn; // must use global as to include the one *from* the settings.php include

$mdb2 =& MDB2::singleton($dsn);

if (PEAR::isError($mdb2)) {
die("<H1> THERE WAS AN ERROR </H1>" . $mdb2->getMessage());
}

echo("SESSION CLASS: if you see this, then we're goood!");     // some very crude debugging, please ignore this!
}




Now, i have another function within this same class:


public static function data_validateUserName($safeUserName){



// build the query
$q = "SELECT uName FROM Users WHERE username = '$safeUserName'";

$result = $this->$mdb2->query($q);

if($result->numRows() >= 1){

// there is 1 or more hits for a username, it is not available!
return false;

} else if ($result->numRows() < 1){

// there is less than 1 row with that username, we're golden!
return ture;

}

}



Inside the constructor, i have correctly set up a MDB2 object.  I was able to run some queries and other things on it *inside* the constructor.  Because of this, i know that it's settings are correct and it is fully working.

However, when i try to use that $mdb2 object inside this other method, i get all sorts of errors about that being a bad reference to an object that essentially does not exist.

Now, i tried searching here, and didn't get much help, so apologies.  If you've got a link to a similar question, then please post that with a brief explanation of what you searched for to get it...


Also, the php.net manual is not very helpful about the scope of objects in this particular setup... so please know that i did pour over that before posting here.

Thanks for your time, all.


***** EDIT ******

I've thought about doing it another way:

Each function is passed in a reference to the MDB2 object as an argument instead of relying on the one that is *suposed to be* built in to the actual class it's self.  Would this be better / more secure / more efficient?!

Hello there   After a few years of spending less and less time coding, I've got a lot of catching up to do. Back when I left I usually would run without classes. Now this is a big deal for me today.   I do understand the concept of classes and already did some working models, mostly from my learning process.   Now here is what is bothering me:

<?PHP

class database {
	// Variables
	public $test;
	
	// Constructor
	public function __construct()
	{
		$test = "4";
	}
	
	
	// Functions
	//
	public function test()
	{
		var_dump($this->test);
	}
	
}

$test = new database;

$test->test();

?>

Wether I run this script on itself, nor through another file, this does work. What i get is:   NULL   The constructor does run, I did an echo inside it. Also it does not matter if the variable is public, private or protected - it will be always NULL.   Error_reporting is on E_ALL, does not show any errors.   What have I overlooked?

I write for example class Text:


class Text {
    public static function test() {
        return 'test text';
    }
}


Today I found this code:


class Text {
     
      /** 
       * Protected constructor since this is a static class.
       *
       * @access  protected
       */  
    protected function __construct(){
        // Nothing here
    }

    public static function test() {
        return 'test text';
    }
}


How much appropriate is to write this?


    /** 
       * Protected constructor since this is a static class.
       *
       * @access  protected
       */  
    protected function __construct(){
        // Nothing here
    }

heres an example of the code i have
Code: [Select]
class someclass
{

public function run($parm)
{
system($parm);
}

public static function create($item1,$item2)
{
$this->run($item1 . $item2);
}

}

then i have a file that attempts to use the create method:
someclass::create($one,$two);

when interpreting, i get this error: "Using $this when not in object context in"

does anyone know how I can fix this? I think I understand why its wrong (the class hasn't really been set up) - I just dont know how to correct it. Is there a way I can access class functions without using $this ? additionally I tried making the run method static too, but that didnt seem to work.

 

My script has 3 classes (that are relevant to this discussion): DB, User and Validate. They are all in independent files and loaded automatically, when required, by an autoloader.
Both the User class and the Validate class have a private variable $_db which is instantiated by their class constructor: $this->_db = DB::getInstance();
At the top of the script I declare new instances: $user = new User(); and $validate = new Validate();
I then call a method in $user: $found = $user->findInUsers ( .... )
From within the findInUsers method I then want to call the query method in the DB class. My problem is that I can't find a way to do this that works.
I have tried $this->_db->query( ... ), $_db->query( ... ), but neither works.

The error messages I am getting a
An error occurred in script '/srv/http/classes/User.php' on line 42: Undefined variable $_db
Uncaught Error: Call to a member function query() on null in /srv/http/classes/User.php:42

Any pointers as to what I am doing wrong, or what I should be doing, would be most welcome.

I have 2 php files. I am unable to get B's global variable from A's static method:

A.php
Code: [Select]
class c_A
  { public static function f_A()
      { include_once( "B.php" ) ;
        print f_B() ;
      }
  }
c_A::f_A( ); // only prints "B : "

B.php
Code: [Select]
$gvs = "global variable from B" ;

function f_B()
  { return "B : " . $GLOBALS[ "gvs" ] ;
  }


any thoughts?


thanks,
Shannon

I have the following simple class:

Code: [Select]
class Settings {
  public static $mysql_datetime_format = "%c/%e/%Y %l:%i %p " . date("[T]");
}

And referencing like:

Code: [Select]
echo Settings::$mysql_datetime_format;

But, I am getting the error: Parse error: syntax error, unexpected '.', expecting ',' or ';'.

Why is this invalid?

Hello, my first post here.

I created a Validation class that depends entirely on static methods. It appears to be working well, but perhaps I misunderstood exactly the purpose and the consequences of using static methods.

My class essentially looks like this:


class Validate
{
static public $errors  = array();
static public $valid   = array();

static public function Name($name)
{
if ($name != '')
{
self::$valid['name'] = $name;
return true;
}
                                else
                                {
                self::$errors['name'] = 'Name is empty';
                return false;
                                 }
}
}


Does this create any chance whatsoever for a collision of data from multiple users? I am beginning to think it does, simply because from what I have recently learned about static methods, theyr'e essentially global variables because they are not instantiated. If that's the case, then it would seem possible that during times of heavy use, any application depending on this class would confuse submitted data.

Any thoughts?

Thanks in advance.

Was just wondering why some people choose NOT to make use of static functions when initializing objects via Factory Classes/Containers.

What are the benefits of initializing the Factory class when for all intensive purposes, it's only used to initialize new classes, etc? 
Does this have any impact on Dependency Injection?  I'm assuming that it doesn't since that would defeat the purpose.

---------

Also, I've noticed that there seems to be an intense stigma within the development community in regard to singletons. 
Are singletons necessarily a bad thing? 

What about database objects? 

One argument I've heard is that this can often impact the flexibility of your application in the event that a new instance of said class needs to be initialized(a second completely separate connection).

However, I was thinking that you could simply store these objects within a static member variable in the factory class; leaving the Database Class' __construct public in the event that you need to create that second/third/fourth connection.

Wouldn't this resolve the issue? 

Hi guys, I am trying something fairly simple but I'm not sure if this would be a good practice. Basically I am using a big class called CommonLibrary that holds common functions as methods and common variables as static variables. But I have some variables here and there like $allAlphabet = range ('a' , 'z'), that cannot be declared as a property because it gives me a parse error.

I don't want to call an object for this class because instancing it is of no use. Values will never change with regards to instances. So the next best thing that I tried was declaring all static variables first, and then changing thei property values inside the class __construct with self::$variable = 'somevalue', and then using this code below to assign values to the empty static variables.


$dummyObject = new CommonLibrary;
unset($dummyObject);
echo CommonLibrary::$staticVariable; // This property is NULL before the constructer is triggered.


Anyone recommend any better ways of doing this?

Thanks in advance!

I found class on the net, and i am having a bit of a problem to understand how does update method works. Here is the code:
Code: [Select]
public function update() {
  global $database;
// Don't forget your SQL syntax and good habits:
// - UPDATE table SET key='value', key='value' WHERE condition
// - single-quotes around all values
// - escape all values to prevent SQL injection
$attributes = $this->sanitized_attributes();
$attribute_pairs = array();
foreach($attributes as $key => $value) {
  $attribute_pairs[] = "{$key}='{$value}'";
}
$sql = "UPDATE ".self::$table_name." SET ";
$sql .= join(", ", $attribute_pairs);
$sql .= " WHERE id=". $database->escape_value($this->id);
  $database->query($sql);
  return ($database->affected_rows() == 1) ? true : false;
}

I have form like this to deal with update:
Code: [Select]
<form action="index.php?page=languages" enctype="multipart/form-data" method="POST">
    <?php foreach($language as $lang){ ?>
    <input type="hidden" name="MAX_FILE_SIZE" value="<?php echo $max_file_size; ?>" />
    <label>Jezik</label><input type="text" size="50" name="language" value="<?php  echo $lang->lang; ?>" /><br>
    <input type="hidden" name="id_lang" value="<?php echo $lang->id_lang; ?>"  />
<label>Slika</label><input type="file" name="image"><?php 
echo "<img src=\"../images/";
echo $lang->image;
echo "\">";
?> <br>
    <label>Pozicija</label><input type="text" name="pozicija" value="<?php echo $lang->pozicija; ?>" size="2" /></p> <br>
<input type="submit" name="submit_update" value="Unesi">
    <?php } ?> 
    </form>
and code to start the function:
Code: [Select]
if(isset($_POST['submit_update'])) {
$language = new Jezik();
$language->update();
}
What next???