I have a rather stupid PHP question :D! I would like to simplify the following statement:
function hello_input() {
return 'Hello World';
}
$helper = 'hello';
$helper = $helper . '_input';
$data = $helperinput();
The specific part I want to simplify is the adding of the _input to the $helper so it calls the right function.
I thought of something like this but it doesn't work:
$data = $helper. 'input'();
or
$data = $helper. 'input' . ();
Any ideas?
Thanks,
Max
Use call_user_func, e.g. $data = call_user_func($helper.'input');.
$helper = 'hello_';
$data = $helper.'input';
call_user_func($data);
That should get you most of the way there. Good luck!
Docs here
Are you expecting to invoke code based on an input? You should never try to do that. That gives people the chance to execute arbitrary code. Even if you can't see quite how, it's still a potential method of attack.
What you probably want is a switch statement (or chained if statements) that match an input and dispatch the correct function.
Get the whole function name into a string first.
$helper = 'hello';
$func = $helper . '_input';
$data = $func();
PHP calls this variable functions. See also variable variables.
Related
i am trying to implement URL mapping in PHP. I have a json file which stores the url and functions which is to execute when that link is requested. I was using eval() but then i came across this
Kepp the following Quote in mind:
If eval() is the answer, you're almost certainly asking the wrong
question. -- Rasmus Lerdorf, BDFL of PHP
now i am thinking is their any other(better) way to do it.
My json file looks like this.
{
"bw/":"main()",
"bw/login":"login()"
}
and my loadPage function look like this.
function loadPage($url){ //$url = 'bw/'
$str = file_get_contents('urls.json');
$this->link = json_decode($str, true);
$url = ltrim($url,"/");
$key = $this->link[$url];
eval("$key;");
}
EDIT:
i defined $this->link in my code
A slight tweak to your JSON to allow you to call the function dynamically would make it easier, just remove the brackets so it would look like...
{
"bw/":"main",
"bw/login":"login"
}
and then call it using...
function loadPage($url){ //$url = 'bw/'
$url = ltrim($url,"/");
$key = $this->link[$url];
$key();
}
A little better way is changing eval() to:
if (function_exists($key)) {
return $key();
}
return default();
and you might create a function "default" to show an error 404 or default page when function doesn't exists.
Cut some word from php available ?
First access to page for example
www.mysite.com/test.php?ABD_07,_oU_876.00/8999&message=success
From my php code, i will get $curreny_link_redirect = test.php?ABD_07,_oU_876.00/8999&message=success
And i want to get $curreny_link_redirect_new = test.php?ABD_07,_oU_876.00/8999
( Cut &message=success )
How can i do ?
<?PHP
$current_link = "$_SERVER[REQUEST_URI]";
$curreny_link_redirect = substr($current_link,1);
$curreny_link_redirect_new = str_replace('', '&message=success', $curreny_link_redirect);
echo $curreny_link_redirect_new;
?>
Your str_replace call is inverse of what it should be. What you want to replace should be the first parameter, not the second.
//Wrong
$curreny_link_redirect_new = str_replace('', '&message=success', $curreny_link_redirect);
//Right
$curreny_link_redirect_new = str_replace('&message=success','', $curreny_link_redirect);
While simple way to do this is to use regex (or even static with str_replace()), I recommend to use built-in functions for url handling. This may be useful when working with complex parameters or multiple parameters:
$data = 'www.mysite.com/test.php?ABD_07,_oU_876.00/8999&message=success';
$url = parse_url($data);
parse_str($url['query'], $url['query']);
//now, do something with parameters:
unset($url['query']['message']);
$url['query'] = http_build_query($url['query']);
$url = http_build_url($url);
-please, note, that http_build_url() is a PECL function (pecl_http to be precise). The way above may look more complex, but it has benefits - first, as I've already mentioned, this will be easy to modify for working with complex parameters or multiple parameters. Second, it will produce valid url - i.e. encode such things as slashes, spaces, e t.c. - in result. Thus, result will always be correct url.
Do like this
<?php
$str = "http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
echo $str = array_shift(explode('&',$str));
Try this:
$current_link_path = substr($_SERVER['PHP_SELF'], 1);
$params = $_GET;
if ($params['message'] == 'success') {
unset($params['message']);
}
$current_link_redirect = $current_link_path . '?' . http_build_query($params);
Maybe not an answer, but a disclaimer for future visitors:
1) I would strongly recommend the function: http://pl1.php.net/parse_url.
And in that case:
$current_link = "$_SERVER[REQUEST_URI]";
$arguments = explode('&', parse_url($current_link, PHP_URL_QUERY));
print_r($arguments);
2) To build new url, use http://pl1.php.net/manual/en/function.http-build-url.php. This is the best, future modifications ready solution I think.
In that case this solution is a little overkill, but these functions are really great, and worth to introduce here.
Best regards
I would like to know if there is a way to bind PHP function inside a regexp.
Example:
$path_str = '/basket.php?nocache={rand(0,10000)}';
$pattern = ? // something i have no idea
$replacement = ? // something i have no idea
$path = preg_replace($pattern, $replacement, $path_str);
Then :
echo "'$path'";
would produce something like
'/basket.php?nocache=123'
A expression not limited to the 'rand' function would be even more appreciated.
Thanks
You could do the following. Strip out the stuff in between the {} and then run an eval on it and set it to a variable. Then use the new variable. Ex:
$str = "/basket.php?nocache={rand(0,10000)}";
$thing = "rand(0,10000)";
eval("\$test = $thing;");
echo $test;
$thing would be what's in the {} which a simple substr can give you. $test the becomes the value of executing $thing. When you echo test, you get a random number.
Don't, whatever you do, store PHP logic in a string. You'll end up having to use eval(), and if your server doesn't shoot you for it, your colleagues will.
Anywhoo, down to business.
Your case is rather simple, where you need to append a value to the end of a string. Something like this would be sufficient
$stored = '/basket.php?nocache=';
$path = $stored . rand(0,10000);
If, however, you need to place a value somewhere in the middle of a string, or possibly in a variable location, you could have a look at sprintf()
$stored = '/basket.php?nocache=%d&foo=bar';
$path = sprintf($stored, rand(0,10000));
I would not try to store functions in a database. Rather store some kind of field that represents the type of function to use for each particular case.
Then inside your crontab you can do something like:
switch ($function)
{
case 'rand':
$path_str = '/basket.php?nocache='. rand(0,10000);
}
e.t.c
as follow:
<?php
/*
* #I'm data
*/
function demo() {}
how to get "I'm data"?
thx
Well, if you are accessing it via the demo() function...
// #I'm Data
function demo(){
$script = file(__FILE__);
$comment = $script[__LINE__ - 5]; // 4 lines above, and 1 for arrays
$temp = explode("#", $comment);
return $temp[1];
}
If your code is inside a class, the correct way is to use reflection:
http://www.php.net/manual/en/reflectionclass.getdoccomment.php
There's no obvious way to do it -- your script is blissfully unaware of its own comments.
However, you could probably hack it by having your script read itself as data, and then parse out whatever you're looking for:
<?php
$my_own_source = file_get_contents(__FILE__);
//some code to pull out exactly what you want here.
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'));