I am trying to reduce code on an API class, what I am looking to do is to make sure a method exists before calling the method inside of the class.
Will be passing a method as a variable need to see if that method exists inside of the class then run the method.
Sample code below:
<?php
class Test {
private $data;
private $obj;
public function __contruct($action,$postArray)
{
$this->data = $postArray;
if (method_exists($this->obj, $action)) {
//call method here
//This is where it fails
$this->$action;
}else{
die('Method does not exist');
}
}
public function methodExists(){
echo '<pre>';
print_r($this->data);
echo '</pre>';
}
}
//should run the method in the class
$test = new Test('methodExists',array('item'=>1,'blah'=>'agadgagadg'));
//should die()
$test2 = new Test('methodNotExists',array('item'=>1,'blah'=>'agadgagadg'));
?>
Is this even possible?
You just need to change $this->$action to $this->{$action}(); and it should work.
More in depth answer here including call_user_func
You have a typo in the name of your constructor function and second, when calling the method_exists() function you should be passing $this as the first parameter, not $this->obj:
public function __construct($action,$postArray)
{
$this->data = $postArray;
if (method_exists($this, $action)) {
$this->{$action}();
}else{
die('Method does not exist');
}
}
Related
By using the following class:
class SafeGuardInput{
public $form;
public function __construct($form)
{
$this->form=$form;
$trimmed=trim($form);
$specialchar=htmlspecialchars($trimmed);
$finaloutput=stripslashes($specialchar);
echo $finaloutput;
}
public function __destruct()
{
unset($finaloutput);
}
}
and Calling the function, by the following code, it works fine.
<?php
require('source/class.php');
$target="<script></script><br/>";
$forminput=new SafeGuardInput($target);
?>
But if in the SafeGuardInput class if I replace echo $finaloutput; with return $finaloutput; and then echo $forminput; on the index.php page. It DOES NOT WORK. Please provide a solution.
You can't return anything from a constructor. The new keyword always causes the newly created object to be assigned to the variable on the left side of the statement. So the variable you've used is already taken. Once you remember that, you quickly realise there is nowhere to put anything else that would be returned from the constructor!
A valid approach would be to write a function which will output the data when requested:
class SafeGuardInput{
public $form;
public function __construct($form)
{
$this->form=$form;
}
public function getFinalOutput()
{
$trimmed = trim($this->form);
$specialchar = htmlspecialchars($trimmed);
$finaloutput = stripslashes($specialchar);
return $finaloutput;
}
}
Then you can call it like in the normal way like this:
$obj = new SafeGuardInput($target);
echo $obj->getFinalOutput();
<?php
try{
$test = new TestAccessModifiers("2345","xyz","vfd","a0001","99","67"); /*invoking the class*/
var_dump($test->calculate());
}
catch(Exception $e){
echo $e->getMessage();
}
?>
<?php
class TestAccessModifiers {
function TestAccessModifiers($user_p,$user_fn,$user_ln,$user_id,$marks1,$marks2) {
echo "hello1";
$this->user_phone=$user_p;
$this->user_fname=$user_fn;
$this->user_lname=$user_ln;
$this->user_id=$user_id;
$this->marks1=$marks1;
$this->marks2=$marks2;
echo $this->marks1;
}
private $additional_marks = 10;
public static function calculate(){
return $this->marks1+$this->marks2+$this->getAdditionalmarks();
}
public function getAdditionalmarks(){
return $this->additional_marks;
}
}
?>
Above is the simple code i am trying to run... but i am unable to call TestAccessModifiers
I have tried using _constructor too
Rename your TestAccessModifiers function to __construct.
public function __construct($user_p,$user_fn,$user_ln,$user_id,$marks1,$marks2) {
echo "hello1";
$this->user_phone = $user_p;
$this->user_fname = $user_fn;
$this->user_lname = $user_ln;
$this->user_id = $user_id;
$this->marks1 = $marks1;
$this->marks2 = $marks2;
echo $this->marks1;
}
Then, remove static from calculate function.
It should then works..
Reference: http://php.net/manual/en/language.oop5.decon.php
if you are calling the class in another php page, make sure you include it like this.
include('/path/to/your/class.php');
$test = new TestAccessModifiers("2345", "xyz", "vfd", "a0001", "99", "67");
or if you are instantiating the object within the same file then place the instantiation code below your class.
class TestAccessModifiers {
public function __construct($user_p, $user_fn, $user_ln, $user_id, $marks1, $marks2) {
echo "hello1";
$this->user_phone = $user_p;
$this->user_fname = $user_fn;
$this->user_lname = $user_ln;
$this->user_id = $user_id;
$this->marks1 = $marks1;
$this->marks2 = $marks2;
echo $this->marks1;
}
private $additional_marks = 10;
public function calculate() {
return $this->marks1 + $this->marks2 + $this->getAdditionalmarks();
}
public function getAdditionalmarks() {
return $this->additional_marks;
}
}
try {
$test = new TestAccessModifiers("2345", "xyz", "vfd", "a0001", "99", "67"); /*invoking the class*/
var_dump($test->calculate());
} catch (Exception $e) {
echo $e->getMessage();
}
you have defined a static method in your class, and have used the pseudo variable $this inside of the static method, which PHP does not allow. since static method is treated out of object context in PHP. you need to remove the static method to use $this
First: Which PHP version you have?
Second: Are you including the class file in the file that you are instancing?
Third: Your function "calculate" is static, then, you can't access to it from an instance and it have no way to read or write properties non-statics.
Try TestAccessModifiers::calculate(); and put in a simple return "Hello World"
Greetings.
What version of PHP are we talking about?
First thing comes to mind: did you add it to autoload ?
I would use the __constructor methode as initiator routine of the class.
public static function calculate() {
return $this - > marks1 + $this - > marks2 + $this - > getAdditionalmarks();
}
You can't operate on $this from a static context. Make this method non-static, or adjust the other variables to be static, whichever suits your context.
I have a similar code snippet like this
class Search
{
public function search($for, $regEx, $flag) //I would like this to be the constructor
{
// logic here
return $this;
}
}
Then I have another class that creates an object from it, later than tries to use the object.
class MyClass
{
public function start()
{
$this->search = new Search();
}
public function load()
{
$this->search($for, $regEx, $flag);
}
}
My question is, is it possible to create an object first THEN give it the parameters?
I know there are some way around this BUT I only ask because I want to use the object like this
$this->search($params);
// I have my methods chained, so I could use it in one line like
// $this->search($params)->hasResults();
if ($this->search->hasResults()) {
echo 'found stuff';
} else {
echo 'didn't find anything';
}
The way I have it set up right now, I would need to use it like this
$this->search->search($params);
if ($this->search->hasResults()) {
echo 'found stuff';
} else {
echo 'didn't find anything';
}
I have a method called search() that does the logic, and I don't want to be redundant in my naming nor do I want to change the name of the method.
I know another way to keep the visual appeal sane I could pass a variable like so
$search = $this->search->search($params);
then
$search->hasResults();
At the same time I am trying to introduce myself to new OOP concepts and learn from them. Would this require passing things by reference? or setting up some type of magic method?
While the previous anwsers show that you can, I wouldn't use it, because it breaks the concept of encapsulation. A proper way to achieve what you want is the following
class Search
{
public function __constructor($for='', $regEx='', $flag='')
{
$this->Setup($for, $regEx, $flag);
}
public function Setup($for, $regEx, $flag)
{
//assign params
//clear last result search
//chain
return $this;
}
public function search()
{
// logic here
return $this;
}
}
In this way, you can reuse the object and have the params in the constructor, without breaking encapsulation.
Yes it is possible
See the below example
<?php
class a{
public $a = 5;
public function __construct($var){
$this->a = $var;
}
}
$delta = new a(10);
echo $delta->a."\n";
$delta->__construct(15);
echo $delta->a."\n";
Output will be:
10 15
Yep, you can.
class Example {
public $any;
function __counstruct($parameters,$some_text) {
$this->any=$some_text;
return $this->any;
}
}
You can call constructor:
$obj = new Example (true,'hello');
echo $obj->any;
$obj->__construct(true,'bye-bye');
echo $obj->any;
I was able to create the visual coding I wanted by using the __call() magic method like this
public function __call($name, $params)
{
$call = ucfirst($name);
$this->$name = new $call($params);
}
from there I could use this
$this->test->search($params);
$this->test->search->hasResults();
I of course now set the search() method to the class constructor
Example code:
class MyClass {
function echo_msg {
echo // now what...
}
function echo_from_inside {
$this->echo_msg()
}
}
result should be:
$my_instance = new MyClass();
$my_instance->echo_msg(); // I was called from OUTside
$my_instance->echo_from_inside(); // I was called from INside
It might be easier, rather than detecting from whence the function was called, to wrap a private function with a public one. Like so:
class MyClass{
private function myob(){
//do something
}
public function echo_msg(){
$this->myob();
//do other stuff like set a flag since it was a public call
}
private function foo(){ //some other internal function
//do stuff and call myob
$this->myob();
}
}
$obj=new MyClass();
$obj->echo_msg();//get output
$obj->myob(); //throws error because method is private
You can try and get the caller of your method:
$trace = debug_backtrace();
$caller = array_shift($trace);
echo 'called by '.$caller['function']
echo 'called by '.$caller['class']
this should work for you.
You could add an optional parameter like such:
function echo_msg($ins=false) {
if($ins){/*called from inside*/}else{/*called from outside*/}
echo // now what...
}
and leave that last. If you are calling it from inside the class, pass it true, otherwise pass nothing!
Ok i have a problem, sorry if i cant explaint it clear but the code speaks for its self.
i have a class which generates objects from a given class name;
Say we say the class is Modules:
public function name($name)
{
$this->includeModule($name);
try
{
$module = new ReflectionClass($name);
$instance = $module->isInstantiable() ? $module->newInstance() : "Err";
$this->addDelegate($instance);
}
catch(Exception $e)
{
Modules::Name("Logger")->log($e->getMessage());
}
return $this;
}
The AddDelegate Method:
protected function addDelegate($delegate)
{
$this->aDelegates[] = $delegate;
}
The __call Method
public function __call($methodName, $parameters)
{
$delegated = false;
foreach ($this->aDelegates as $delegate)
{
if(class_exists(get_class($delegate)))
{
if(method_exists($delegate,$methodName))
{
$method = new ReflectionMethod(get_class($delegate), $methodName);
$function = array($delegate, $methodName);
return call_user_func_array($function, $parameters);
}
}
}
The __get Method
public function __get($property)
{
foreach($this->aDelegates as $delegate)
{
if ($delegate->$property !== false)
{
return $delegate->$property;
}
}
}
All this works fine expect the function __set
public function __set($property,$value)
{
//print_r($this->aDelegates);
foreach($this->aDelegates as $k=>$delegate)
{
//print_r($k);
//print_r($delegate);
if (property_exists($delegate, $property))
{
$delegate->$property = $value;
}
}
//$this->addDelegate($delegate);
print_r($this->aDelegates);
}
class tester
{
public function __set($name,$value)
{
self::$module->name(self::$name)->__set($name,$value);
}
}
Module::test("logger")->log("test"); // this logs, it works
echo Module::test("logger")->path; //prints /home/bla/test/ this is also correct
But i cant set any value to class log like this
Module::tester("logger")->path ="/home/bla/test/log/";
The path property of class logger is public so its not a problem of protected or private property access.
How can i solve this issue? I hope i could explain my problem clear.
EDIT:
A simple demonstration
Modules::Name("XML_Helper")->xmlVersion ="Hello"; // default is 333
$a = Modules::Name("XML_Helper")->xmlVersion; // now $a should contain "Hello"
echo $a; // prints 333
What i need is
Modules::Name("XML_Helper")->xmlVersion ="Hello"; // default is 333
$a = Modules::Name("XML_Helper")->xmlVersion; // now $a should contain "Hello"
echo $a; // prints Hello
I realise you already said that path is public, but it's still worth mentioning: If you're using PHP 5.3.0+, note this quirk of property_exists():
5.3.0 | This function checks the existence of a property independent of
accessibility
In other words, if you check if (property_exists($delegate, $property)), you have no guarantee you have access to $delegate->$property for writing (or reading, for that matter, but you are trying to write).
As for actual troubleshooting: You could try checking if your if (property_exists($delegate, $property)) statement actually executes. If it doesn't, check the case of $property.
Sidenote: It's fairly hard to read the code you posted up, which makes it a bit of a pain to troubleshoot. Could you edit your post and indent it properly?
The path property of class logger is public so its not a problem of
protected or private property access.
That's your problem. From the docs:
__set() is run when writing data to inaccessible properties.
That suggests that __set() is not called for public properties.