I'm a .net programmer that recently decided to check PHP out and so far I must say that it's quite fun.
I use WAMPServer to work with PHP and I'm having a problem when using by reference variables.
This is the code I'm using:
function drawCategories($parent_id, $catlistids="",$level=0,$selected="") {
global $USERLANG;
$result = mysql_query("
SELECT
BPPENNYAUTOBID_categories.cat_id,
BPPENNYAUTOBID_cats_translated.cat_name
FROM
BPPENNYAUTOBID_categories
INNER JOIN BPPENNYAUTOBID_cats_translated ON BPPENNYAUTOBID_categories.cat_id=BPPENNYAUTOBID_cats_translated.cat_id
WHERE
BPPENNYAUTOBID_cats_translated.cat_name!=''
AND BPPENNYAUTOBID_categories.parent_id='".$parent_id."'
AND BPPENNYAUTOBID_cats_translated.lang='".$USERLANG."'
ORDER BY
BPPENNYAUTOBID_categories.cat_name"
);
while ($line = mysql_fetch_array($result)) {
if($catlistids != "") { $catlistids .= "<br />"; }
$spaces = "";
for($i=0;$i<$level;$i++) $spaces .=" ";
$catlistids .= "<option value='".$line['cat_id']."' ".($selected==$line['cat_id'] ? " selected ":"").">".$spaces.$line["cat_name"]."</option>";
drawCategories($line["cat_id"], &$catlistids,$level+1,$selected);
}
return $catlistids;
}
When I call the drawCategories function the second time passing the variable $catlistids by reference then all the website content disapears, I don't get any kind of error but I suppose it's something to do with WAMP server definitions.
Can anyone help me solve this problem?
Thanks in advance
There is no reference sign on a function call - only on function definitions. Function definitions alone are enough to correctly pass the argument by reference. As of PHP 5.3.0, you will get a warning saying that "call-time pass-by-reference" is deprecated when you use & in foo(&$a);. And as of PHP 5.4.0, call-time pass-by-reference was removed, so using it will raise a fatal error.
You can pass a variable by reference to a function so the function can modify the variable. Remove & from function call and try this way:
function drawCategories($parent_id, &$catlistids="", $level=0, $selected="") {
//^
Related
I'm fairly new to PHP, and i have a problem in defining a function that returns an array containing a price and description strings.
I am using the "simple html dom" php files that facilitates parsing.
The function i create requires 2 arguments : the link (from which it will grab data) and the id (used to get the proper css syntax).
This is the get_product_details.php
<?
require_once 'simple_html_dom.php';
$priceMatchTable=('span[id=our_price_display]');
$descMatchTable=('div[id=short_description_content]');
function get_prod_details( $link , $id ) {
global $priceMatchTable, $descMatchTable;
$html = file_get_html($link);
$result['price'] = $html->find($priceMatchTable[$id],0);
$result['desc'] = $html->find($descMatchTable[$id],0);
return $result;
}
And this is the main php:
<?php
include 'get_product_details.php';
$link = 'http://micromedia.tn/barette-memoire/1170-barette-m%C3%A9moire-1go-ddr-ii.html';
$id = 0;
$result = get_prod_details($link, $id);
echo $result['price'];
?>
Finally i get an error which tell:
find($priceMatchTable[$id],0); $result['desc'] = $html->find($descMatchTable[$id],0); return $result; }
Fatal error: Call to undefined function get_prod_details() in C:\xampp\htdocs\dom\index.php on line 8
Best regards!
This may sound silliy, but is
include 'get_product_details.php';
really pointing towards "get_product_details.php"?
Disable (//) the function call in you index.php and add a simple echo to your "get_product_details.php" to see if the file gets included.
I think you need something like:
include '/path/from/root_to_your/directory/get_product_details.php';
If your trying this in Windows land, it will look something like:
include 'C:\Documents\something\get_product_details.php';
I'm just learning PHP, and I'm sure I'm not the first person to try something like this, but maybe because I didn't know what to call it, I couldn't find any other examples or questions on here or from a search on google.
I wanted to create a function which takes two parameters and uses them to create all the short style variables I'll be using later in my script.
My problem is where normally the syntax to create a short variable is something like:
$var = $_METHOD['var'];
but I'm trying to do this using variables and don't know how to get the syntax right. Here's my code:
<?php
session_start();
function shortnames($some_vars, $type) {
for ($i = 0; $i<(count($some_vars)); $i++) {
$$some_vars[$i] = $_$type['$some_vars[$i]'];
echo $$some_vars[$i].' = '.$some_vars[$i].'<br />';
}
}
$post_vars = array(lastname,firstname,payment);
$session_vars = array(sessiontxt,province,city,venue,regfee);
shortnames($session_vars,session);
shortnames($post_vars,post);
?>
Thanks for helping a beginner!!
function mainFunction() {
functionA(5, "blah");
functionB("ok", "whatever");
}
How to write a function GetFunctions that returns the functions within mainFunction?
How to call them with the parameters given in mainFunction?
How to call them as follows?
foreach (GetFunctions(mainFunction) as $function) {
print "Calling function $function: ";
call($functionA); // called with parameters(5, "blah")
}
Working in PHP 5.2.8
EDIT: OK, here's a more complete explanation. I tried to keep it simple to make it easy to understand, but apparently that wasn't a good idea.
The goal is to call each assertion within a given static method. I am writing a testing framework. Each assertion returns true or false.
I am calling the methods as follows.
$methods = get_class_methods('LibraryTests');
foreach ($methods as $method) {
if ( StartsWith($method, 'Test') ) {
print "calling: " . $method . ": ";
call_user_func('LibraryTests::' . $method);
}
}
The above code calls each method within the class, but I want to call each assertion individually and track the result (true/false). CallAssertion is supposed to call each assertion (such as TestUnit::AssertEqual(GetFormattedHour(5), "5 PM");). This is the method that I am asking about.
Here is the class:
class LibraryTests extends TestUnit {
static $success = 0;
static $failure = 0;
static $total = 0;
static function CallAssertion($assertion) {
self::$total += 1;
if ($assertion) { self::$success += 1; }
else { self::$failure += 1; }
}
static function TestGetFormattedHour() {
TestUnit::AssertEqual(GetFormattedHour(5), "5 PM");
TestUnit::AssertEqual(GetFormattedHour(16), "4 PM");
}
So, the question is, how to write CallAssertion?
You can't.
Instead, create a class and use reflection to get its methods.
Regardless, you'll want to figure out why this is necessary and see if there is an entirely different approach you can use.
(If this is for debugging purposes, you can use debug_backtrace to inspect but its purpose is not for calling functions as you have described in your question.)
Hmm, what problem are you actually trying to solve. To me it sounds like you're trying to inspect the call stack at runtime. If so, I'd suggest just using debug_backtrace() (src).
I wouldn't suggest using that function in production as much though, as it's a rather heavy hit on your code.
One possibility would be to do a file_get_contents on the PHP file that contains main_function, then go through it to parse out main_function and the functions it calls. Of course, I don't know your situation so that might not work.
You can do this with:
http://php.net/manual/en/function.token-get-all.php
Probably a bad idea, but good luck!
Please could someone experienced in PHP help out with the following. Somewhere in my code, I have a call to a public static method inside a non-instantiated class:
$result = myClassName::myFunctionName();
However, I would like to have many such classes and determine the correct class name on the fly according to the user's language. In other words, I have:
$language = 'EN';
... and I need to do something like:
$result = myClassName_EN::myFunctionName();
I know I could pass the language as a parameter to the function and deal with it inside just one common class but for various reasons, I would prefer a different solution.
Does this make any sense, anyone? Thanks.
Use the call_user_func function:
http://php.net/manual/en/function.call-user-func.php
Example:
call_user_func('myClassName_' . $language . '::myFunctionName');
I think you could do:
$classname = 'myClassName_' . $language;
$result = $classname::myFunctionName();
This is called Variable Functions
I would encapsulate the creation of the class you need in a factory.
This way you will have a single entry point when you need to change your base name or the rules for mapping the language to the right class.
class YourClassFactory {
private $_language;
private $_basename = 'yourclass';
public YourClassFactory($language) {
$this->_language = $language;
}
public function getYourClass() {
return $this->_basename . '_' . $this->_language;
}
}
and then, when you have to use it:
$yourClass = $yourClassFactoryInstance->getYourClass();
$yourClass::myFunctionName();
As temuri said, parse error is produced, when trying '$className::functionName' :
Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM ...
In my case (static method with 2 arguments), best solutions is to use call_user_func_array with 2 arrays (as suggested by nikc.org):
$result = call_user_func_array(array($className, $methodName), array($ard1, $arg2));
BR
although i think the way you deal is a very bad idea, i think i may have a solution
$className = 'myClassName_'.$language;
$result = $className::myFunctionName();
i think this is what you want
You can easily do next:
<?php
class B {
public static $t = 5;
public static function t($h) {
return "Works!" . $h;
}
}
$g = 't';
$class = 'B';
echo $class::$g('yes'); //Works! Yes
And it will works fine, tested on PHP 5.2 >=
As far as i could understand your question, you need to get the class name which can be done using get_class function. On the other hand, the Reflection class can help you here which is great when it comes to methods, arguments, etc in OOP way.
Solutions like:
$yourClass::myFunctionName();
will not work. PHP will produce parse error.
Unfortunately, the only way is to use very slow call_user_func().
I know it's an old thread, but as of PHP 5.3.0 you should be using forward_static_call
$result = forward_static_call(array('myClassName_EN', 'myFunctionName'));
Using your $language variable, it might look like:
$result = forward_static_call(array('myClassName_' . $language, 'myFunctionName'));
I'm new to PHP and web scripting in general so this a newb question.
Currently i'm a creating an instance to an object, yet when I call the constructor
the script slienty shuts down... it doesn't call the next function and I don't know why.
Any help would be welcome.
Here is the code.
<?php
class product {
var $ssProductName;
var $ssVendorName;
var $ssDescr;
var $ssURI;
// Clean constructor, strings must be cleaned before use
function __construct($ssProd, $ssVendor, $ssD, $ssU) {
$this->$ssProductName = $ssProd;
$this->$ssVendorName = $ssVendor;
$this->$ssDescr = $ssD;
$this->$ssURI = $ssU;
}
// print a table of the values
function DisplayOneEntry() {
echo '<table border="1">
<tr>
<td>'.$this->$ssProductName.'</td>
<td>'.$this->$ssVendorName.'</td>
<td>'.$this->$ssDescr.'</td>
<td>'.$this->$ssURI.'</td>
</tr>
</table>';
}
}
echo "<HTML>";
echo "A";
$newP = new product("Redhat", "Redhat corp", "Leader in", "www.redhat.com");
echo "B";
$newP->DisplayOneEntry();
echo "</HTML>";
?>
But the output is just:
<HTML>
A
Then nothing else.
This is running on a hosting provider using php 5.2.9 and Apache 2.2.
You need to access the member variables with:
$this->variableName
Not:
$this->$variableName
$this->$ssProductName = $ssProd;
should be
$this->ssProductName = $ssProd;
no $ after the ->
The syntax $this->$foo is a variable variable referencing the class attribute with the name of the value of $foo. So if $foo has the value bar, $this->$foo would reference $foo->bar and not $this->foo.
So just remove the $ after $this-> and it should work.
That is because your php script is erroneous. To catch such errors, you should run it on a debugging server (with display_errors set to On) or use other logging methods.
However, the main problem is you are accessing object members the wrong way; there's no second dollar sign. Instead of
$this->$ssProductName = $ssProd;
use
$this->ssProductName = $ssProd;