PHP - Basic Oop Question: Using Classes In Multiple Files

Currently I'm learning about objects and classes. I followed a tutorial about making a DB abstraction class (a mySQL select) and then I tried to adapt it and wrote a method to Insert a new name. However, then I had a problem: what if the value already exists in the DB?

So I thought maybe I could write a method for that too, and hopefully this would be re-usable for other purposes.

So I'm posting the code here and I hope someone could take a look at it, since I do not want to start any bad practices and start a habit of writing sloppy code. Would the code below be considered 'good code'?



<?php
// This file is called database.php

class database {

public $mysql;
function __construct() {
$this->mysql = new mysqli('localhost', 'root', 'password', 'db') or trigger_error('Database connection failed');
}

/* Function to check whether value: $queriedName already exists inside table: $table and column: $column  */
function findMatch($table, $column, $queriedName) {
if ($result = $this->mysql->query("SELECT * FROM $table WHERE $column='$queriedName'")) 
{
if (!$numberOfRows=$result->num_rows) {
return false;
}

else {
return true;
}
}
}

/* Function to select all records from table: $table */
function selectAll($table) {
if ($result = $this->mysql->query("SELECT * FROM $table") ) {
while($row=$result->fetch_object()) {
$nameFields[]=$row->names;
}
return $nameFields;
}
}

/* Function to insert a name: $newName into table: $table. Uses method finMatch to avoid doubles */
function insertName($table, $newName) {
if ($this->findMatch($table, 'names', $newName)) {
$result="Person already exists!";
return $result;
}

else {
$result = $this->mysql->query("INSERT INTO $table(names) VALUES ('$newName')");
return $result;
}

// 
}
}

?>

Main page:


// This file is called index.php
require('database.php');
$newName='Mary Jane';
$result=$myDb->insertname('mytable', $newName);
echo $result;

Hello, I'm new to the forum and I'm looking for advice.

I use a bunch of classes in namespaces that are I'm attempting to organize for autoloading. In other words, a class called \Foo\Package\Class is loaded from the file at Foo\Package\Class.php. I'm using spl_autoload for this. (If I were on 5.2 I could be using underscore-delimited pseudo-namespaces just as well; the implementation detail isn't important)

Now, I want to have multiple separate apps that use a single common library. Each app also has some classes that are local to it. How should I solve the autoloading problem?

I thought of the following approach. Is it any good?
Try autoloading from the common class library If it fails, try autoloading from the app's own local library
Part 2 of the question:

Within my apps, though, there are two types of classes: library ("vendor") classes that are only being used in that particular app so they don't need to be in the shared library, and app-specific classes that are the core of the app (so they, by definition, don't need to be in any shared library). I'd probably like to keep these two separate, so I'd need to add point #3 to the list above: search in the "core" class hierarchy of the local app. This gives 3 separate locations, and the problem is that they negate the advantages namespaces since there can be overlap. In which case one class will override the other during autoloading. So order of the above list would matter. And time would be wasted looking for a class in the first two places if it's more often in the third.

A solution I was considering is sticking to just one central library of classes (and dumping all app-local libraries there). Then, the core classes that belong to one app would be under an \AppName namespace.

I'm looking forward to some insights from the experts. How do you guys organize your class libraries?

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.    

Does it matter where you start your session at? Does it have to be before the <!doctype> tag or can it go anywhere in the page?

Hi, can you help me please?

I have some code written about 5 yrs ago that is for example like this

echo"<div class=\"select\">";
echo"<br /><br />\n";
echo"</div>\n";
echo"</div>\n";
echo "<p><b>$address</b></p>\n";

Does it make any difference at all if I amended it to

echo"<div class=\"select\"><br /><br /></div></div><p><b>$address</b></p>";

ie coding errors or increase load time?
also when should I use \n"; or ";

Please forgive my ignorance but I am a self taught php writer and have managed to teach myself but just need a little help. Cheers

is it okay to name a column "date" in a table ??? just want to know whether this could mess up everything

thanks in advance

I would like to keep all my classes in a folder placed within the htdocs folder where my php script runs.  Let's say the classes folder is com\jimslounge\classes.  From my script can I instantiate a class like this
$myClass = new com\jimslounge\classes\Jimsclass();  Does it work something like that?  I would hate to have to use include to access classes.

Hello,

Im from the Netherlands and i have a little question about php.

I have a form in php where administrators can make new users. They can fill in a name, password, age and can select a role. The role is a dropdown menu where they can select athlete, researcher and trainer. My problem is that when they select a role, i want that selected role transfert to a php variable. I want to use the variable in a if statment, when sporter selected a new dropdown appears with options like tennis, hockey....

I have seen a lot on google about this with jquery and stuff, but i cant find a good example.

Can u help me?

Thanks.

Quote from: http://www.killerphp.com/tutorials/object-oriented-php/php-objects-page-1.php

getter and setter names should match the property names. This way, when other PHP programmers want to use your objects, they will know that if you have a method/function called 'set_name()', there will be a property/variable called 'name'.


Is this an accurate statement? Even if there's like 20+ properties? That would be 40+ methods and that's not including doing anything with those properties but setting/getting. That sounds...I don't know...against the grain.

sorry guys its been a long day and this is an extreme newbie question but for whatever reason right now I cant wrap my head around the concept right now...
say for instance one wanted to make a db for job postings, where one could go and see many different categories etc etc. Would you create a table "jobs" and then create rows for the types ie) Accounting, Business, Customer Service, etc. - or would those be all seperate tables as well? Cause im just thinking of the INSERT INTO query, and say I wanted to add a job but I only wanted to add one to the Customer service portion of the jobs table...thats why im curious if everything should be different tables so you could just do INSERT INTO customer_service etc etc and then have all of the persons names/creditials there? OR is it possible to create a table within a table? or am I simply going nuts here? lol. thanks

OK, I think this is easy, but I just can't seam to get it figured out.

I have this piece of code

echo '<img src="maps/' . $map . '.jpg" />';

And what I want to do is if that $map is not in the directory I want it to display a standard image that I know is in the directory.

So basically I want the alt tag to be a image instead of text.

I just want to ask the logic of making a chatroom.
Is it correct if i prepare a table in MYSQL, php script to submit whatever words typed and use AJAX to refresh every second to be sure that all input displayed

thanks

probably a very stupid question, but i pose it because it's counterintuitive for me to write it:

i find in alot of wordpress code if statements like:

if ( false === $var)

i suppose it's the same as if ( $var === false) ? why would one right it in the first way?

Hi,

I just started learning PHP... Below is my first programme infact..

Out put is not coming when i type some thing in input boxes...

Can somebody suggest where is the error...

Index.php

<html>
<head>
<title>Welcome to our site</title>
</head>
<body>

<form method="POST" action="submit.php">
<label for ="business_name">Business name</label>
<input type="text" id="business_name" \><br/>
<label for ="contact_person">Contact person</label>
<input type="text" id="contact_person" \><br/>
<label for ="Telephone">Telephone</label>
<input type="text" id="Telephone" \><br/>
<label for ="FAX">FAX</label>
<input type="text" id="FAX" \><br/>
<label for ="Mobile">Mobile</label>
<input type="text" id="Mobile" \><br/>
<label for ="Addres_line_1">Addres_line_1</label>
<input type="text" id="Addres_line_1" \><br/>
<label for ="Addres_line_2">Addres_line_2</label>
<input type="text" id="Addres_line_2" \><br/>   
<label for ="Addres_line_3">Addres_line_3</label>
<input type="text" id="Addres_line_3" \><br/>
<label for ="Addres_line_4">Addres_line_4</label>
<input type="text" id="Addres_line_4" \><br/>
<label for ="City">City</label>
<input type="text" id="City" \><br/>
<label for ="Pin_code">Pin_code</label>
<input type="text" id="Pin_code" \><br/>
<label for ="State">State</label>
<input type="text" id="State" \><br/>
<label for ="email">email</label>
<input type="text" id="email" \><br/>
<input type="submit" value="Please submit the details" name="submit"/>
</form>


</body>
</html>   

submit.php



<head><title>Your submission details</title></head>
<body>
<H3>YOU HAVE SUBMITTED THE FOLLOWING DETAILS</H3>
<?php

$business_name= $_POST["business_name"];
$contact_person = $_POST["contact_person"];
$Telephone = $_POST["Telephone"];
$fax = $_POST["FAX"];
$mobile = $_POST["Mobile"];
$address1 = $_POST["Addres_line_1"];
$address2 = $_POST["Addres_line_2"];
$address3 = $_POST["Addres_line_3"];
$address4 = $_POST["Addres_line_4"];
$city = $_POST["City"];
$pincode = $_POST["Pin_code"];
$state = $_POST["State"];
$email = $_POST["email"];

echo "Your business name".$business_name.'<br/>';
echo "Contact person".$contact_person.'<br/>';
echo "Telephone no.".$Telephone.'<br/>';
echo "Fax No.".$fax.'<br/>';
echo "Mobile No.".$mobile.'<br/>';
echo "Address line one".$address1.'<br/>';
echo "Address line two".$address2.'<br/>';
echo "Address line three".$address3.'<br/>';
echo "Address line four".$address4.'<br/>';
echo "Your City".$city.'<br/>';
echo "Your Pincode".$pincode.'<br/>';
echo "Your State".$state.'<br/>';
echo "Your email".$email.'<br/>';
?>
<a href=index.php>Home</a>
</body>
</html>

Hello!   I'm newbie in PHP(started 3 days ago), and i have two questions about the same topic, i hope you can answer me.   1- Is there methods in php for interaction with webpages as javascript, as they simulate a user interacting with these pages? For example, the method click () or the getElementsByClassName () for you to find something specific on the page. There are methods that do this in php?   2- To interact with a website using a sript (to click on links or save the url of pictures in an array) i start "JavaScript Scratchpad" Firefox with Shift + f4 and then it runs the script there, is just be on the page i want. If i want to do something similar in php, how can i run this script on my browser or is it done another way?   Thanks!