PHP - Structuring Classes

Good Afternoon,

I'm having trouble working out how to structure my class, I don't think how it currently is structured is as efficient as it could be. It does work how it currently is, but probably is not the most ideal way to go about doing things?

The class goes something like this...
class Name {
     public $x;
     public $a1, $a2, $a3, $a4;

     __construct($x=array(1)) {
         $this->x = ValidateArray($x);
         $a1 = self::Method1($this->x);
         $a2 = self::Method2($this->x);
         $a3 = self::Method3($this->x);
         $a4 = self::Method4($this->x);
} 

    private ValidateArray($x) {
    // validate the array
    return $this->x;
}

    public Method1($x) {
    $x = ValidateArray($x);
     // do stuff
    return $this->a1;   
}   

    public Method2($x) {
    $x = ValidateArray($x);
     // do stuff
    return $this->a2;   
}   

    public Method3($x) {
    $x = ValidateArray($x);
     // do stuff
    return $this->a3;   
}   

    public Method4($x) {
    $x = ValidateArray($x);
     // do stuff
    return $this->a4;   
}   

}

I'm sure there must be an easier way to use ValidateArray(); in each method? If I want to call a public method on it's own, is there a way to cancel the __construct() ? seems inefficient for the __construct() to run all the methods if I'm not using the instantiation to pass an array as an argument, but rather just want to use a particular method?
Thank you in advance for any help/suggestions and insight.

Kind Regards,
Ace

I'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;
// iMagic

what 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 Battery

I 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.    

Hey,   I have am creating a web app to hold customer and job details.. I have the following table structures to hold the data:  

CREATE TABLE Customers (
  customerID int(5) NOT NULL auto_increment,
  customer varchar(25) default NULL,
  contact varchar(25) default NULL,
  phone varchar(25) default NULL,
  email varchar(25) default NULL,
  address varchar(25) default NULL,
  PRIMARY KEY (customerid)
) ENGINE = INNODB;


CREATE TABLE Jobs (
  jobID int(5) NOT NULL auto_increment,
  customerID int(5) NOT NULL default '0',
  invoiceNumber varchar(25) default NULL,
  purchasOrder varchar(25) default NULL,
  orderDate datetime NOT NULL default '0000-00-00',
  dateRequired datetime NOT NULL default '0000-00-00',
  jobStatus varchar(25) default NULL,
  PRIMARY KEY (jobID)
) ENGINE = INNODB;


CREATE TABLE vinyl (
  vinylID int(5) NOT NULL auto_increment,
  jobID int(5) NOT NULL default '0',
  colour varchar(25) default NULL,
  font varchar(25) default NULL,
  size varchar(25) default NULL,
  fileLocation varchar(25) default NULL,
  PRIMARY KEY (vinylID)
) ENGINE = INNODB;


CREATE TABLE screenprint (
  screenprintID int(5) NOT NULL auto_increment,
  jobID int(5) NOT NULL default '0',
  colour varchar(25) default NULL,
  font varchar(25) default NULL,
  size varchar(25) default NULL,
  fileLocation varchar(25) default NULL,
  PRIMARY KEY (screenprintID)
) ENGINE = INNODB;


CREATE TABLE items (
  itemID int(5) NOT NULL auto_increment,
  jobID int(5) NOT NULL default '0',
  supplier varchar(25) default NULL,
  code varchar(25) default NULL,
  colour varchar(25) default NULL,
  style varchar(25) default NULL,
  total varchar(25) default NULL,
  dateOrdered varchar(25) default NULL,
  PRIMARY KEY (itemID)
) ENGINE = INNODB;


CREATE TABLE itemsqty (
  itemqtyID int(5) NOT NULL auto_increment,
  itemID int(5) NOT NULL default '0',
  jobID int(5) NOT NULL default '0',
  size varchar(25) default NULL,
  quanity int(5) NOT NULL default '0',
  PRIMARY KEY (itemqtyID)
) ENGINE = INNODB;


CREATE TABLE embroidery (
  embroideryID int(5) NOT NULL auto_increment,
  jobID int(5) NOT NULL default '0',
  code varchar(25) default NULL,
  stitchCount varchar(25) default NULL,
  quanity int(5) NOT NULL default '0',
  PRIMARY KEY (embroideryID)
) ENGINE = INNODB;

Are these tables set out correctly for the collection of data needed. Also.. am I best to use Foreign Keys? My understanding of using foreign keys is not in place for queries as such, more to keep the tables clean of miss matched records etc?   Thanks

I have been reading in Larry Ullmans book "Visual QuickPro Guide PHP 6 and MySQL 5" and I find it well-written. Since it is from 2008, it does not contain anything about MySQL PDO, but rather does it in the mysqli_* way. Larry suggest placing the secret database password and more along with a database connection script in a connect.php file, placed above the webroot if possible. Then later, when he is creating queries and executing them in other php files, he includes the connect.php file before making the queries.   Now I know it is very important to be careful with the Error handling, so the script won't output errors, which could reveal something about the database making it less secure. Therefore I am wondering how to structure things when using PDO. I need to write error-handling scripts for the following situations:   a) Connection to the database doesn't succeed b) The execution of the queries doesn't succeed c) User input in HTML forms are not appropriate   and probably more. The recommended way of handling errors when using PDO seems to be writing some try-catch code. But then I don't see how I can keep the connection to the database completely inside the connect.php file. Either I will need to use a die() or exit() inside this file or I will need to give up my idea to keep everything which concerns the connection to the database in the file mentioned AND write nested try-catch sentences - first make sure the connection works, then make sure the query will execute properly.   I don't like either of those approaches. Firstly I have been told that using exit() is bad programming and secondly it seems to get more complicated using nested try-catch code and to let database connection take part in diverse php-files.   Maybe somebody have a smart, convenient and secure way to do it?   Erik  

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?