if (isset ($_POST['somethingA']))
{
//code for doing something A
}
elseif (isset ($_POST['somethingB']))
{
//code for doing something B
}
I will need to access some data from somethingA code, into somethingB code.
How can I do that in a proper way?
Should I declare a variable outside the conditionals, work inside the conditionals, and later (bottom) I use that?
Should I work with them inside the conditionals, and, somehow, pull them out after the conditional lines?
Thanks in advance,
MEM
you may do something like you said:
$innervar = null;
if (isset ($_POST['somethingA']))
{
$innervar = new A();
//code for doing something A
}
elseif (isset ($_POST['somethingB']))
{
$innervar = new B();
//code for doing something B
}
$innervar->CommonMethod();
If you are accesing $_POST directly consider using some sort of framework like symfony, or Zend, unless you are learning or working in a very simple(house) project.
Best of luck
David
You should just declare the variable outside. So you can use and access the resources in both
According to your clarification the comments, you want to share data between two successive executions of the PHP script. That's not a question of where to put your variables in the ocde. You want the code to run once, compute some value, and then have this value available when the code is run again.
There are two ways of doing this:
Put the value into a hidden input field on the webpage
Put the value into the user session (which means it's stored "somewhere" by the PHP runtime and made available for all subsequent requests with the same session ID)
Related
Before I explain the issue, I know the risks of using eval, but there is no realy other way to do it on how my system is build, and it also is for a personal project only. (its a custom cms which when I publish it makes the physical files for me, I just made it though db so I don't need to upload files when not working remote and it is just easy).
Lets explain my issue, I have a main php file which handles all pages, all pages are stored in the db with code and all and is being executed through eval.
And the system also has a function include_db which basicly does the same as include from php normaly just from the db.
But when I access a variable defined in the first eval (main page) it can not be read out in the included eval from the db.
Weird thing is that functions can be read out though the second eval.
Any way to access variables normaly from the included eval that is being generated in the eval of the main page?
(I think it has to do because those variables are not global and its being executed in a function but I do not know a way to make every variable global :( )
Thanks in advance!
The code that is being evalled on the main page:
$skill = isset($_REQUEST['skill']) && is_string($_REQUEST['skill']) && isValidSkill($_REQUEST['skill']) ? $_REQUEST['skill'] : 'overall';
if(!isset($_REQUEST['player']))
include_db('highscore_overview');
else
include_db('highscore_player');
And inside the include of overview I dump the get_defined_vars() and that doesn't return the $skill I set before the include only the variables that are declared in the main index.php (database and such)
First of all a disclaimer: You should never ever execute code from a database. That is a big security risk. It means that whenever someone is successful in gaining access to your database (using sql-injection for example) is now also capable of executing arbitrary code in php by changing the code in your database. You really should not do that!
If you are using code from the database to implement custom (email-)templates, please consider using a templating-engine for that like twig. Most syntaxes of template-engines are built in a way that you cannot break out of them and execute arbitrary code like you could with raw php code.
That said, i now try to answer the original question (because i cannot stop you doing things you should not do anyways). In terms of variable-scope, eval behaves like a function. If you want the variables defined inside it global, you have to manually make every variable defined inside the eval global.
You can do that by append a code-snippet to every code executed in eval that takes every local (in eval defined) variable and writes it into global scope.
<?php
function include_db() {
# ... get $code from db here ...
# get's executed after code from db, globalizes all variables
$code .= ';foreach (get_defined_vars()) as $newGlobalName) {';
$code .= ' $GLOBALS[$newGlobalName] = $$newGlobalName;';
$code .= '}';
eval($code);
}
this is my first time using PHP in a real project environment. The project is pretty simple, take an existing, working PHP site and update the HTML to be consistent with HTML5. After designing the HTML, I am inserting the PHP from the previous site. This works most of the time, but I get a few errors. For instance:
<?
$sec = $_GET['sec'];
if ($sec == "1") {
echo ('Success!');
}
?>
Is causing the error:
Notice: Undefined index: sec in /file_that_holds_site_build.
Of course that is only if the url doesn't include the append tag (=1) that alerts the message.
So the question is this, what am I missing that causes the $GET when there is no $sec? How do I eliminate this error on first page load?
You're getting that notice because you're trying to access an array index that doesn't exist in some scenarios. Here's how you should be getting the data out of the request.
$sec = array_key_exists('sec', $_GET) ? $_GET['sec'] : null;
Thanks to everyone who provided possible answers to this question. It was Daniel that came up with the easiest fix. Again, I am just adjusting someone else's code to work, so a universal solve would involve too much of my own writing. To the point, the final code looks like this:
<?
if (isset($_GET["sec"])){
$sec = $_GET['sec'];
if ($sec == "1") {
echo ('Success! Your username and password have been sent via email.');
}}
?>
Notice the added if statement. As I said in a comment to Daniel, SO SIMPLE!
Thanks again for everyone's help. I hope to be likewise of service to you all soon.
Simple just use isset($_GET['sec']) to check for the parameter 'sec' before using it in the php code. That should eliminate the error. This is quite trivial I suppose.
I often simply extract() the wohle $_GET super global and then either get the desired variable or not. As a kind of "declaration" I initialize each expected variable first with false. This way I find it much easier to handle than individually doing a check like if(isset($_GET['element'])) ...
$var1=$var2=$var3=false; // my desired variables
extract($_GET); // everything I get from the form
// or: extract($_REQUEST);
if ($var1) { /* do something with it */ }
Possible security risk:
Of course you should be aware that everybody could simply include their own variable as an argument to he page ...
I am actually trying to monitor a PHP variable (may be as a separate thread but not possible in PHP) and fire a PHP function whenever the value of the variable changes.
eg: lets take a variable $_GLOBALS['foo']=1;
if at any point in the code, the value of $_GLOBALS['foo'] changes to something else, i want to fire a PHP function immediately.
The variable can be anywhere inside a loop or in a function,etc.
Why i want this: I have a variable which stores the last error occured as a text. If the value of the variable changes from "" to something else, i want to trigger an error. My LOGIC may seem a bit strange but this is what i would like to do.
Thanx in advance.
Edit: I tried: How to use monitors in PHP? and How can one use multi threading in PHP applications but does not seem to solve the problem.
The Code (Thought this could solve some of your doubts on my question):
public function addtag($tagarray,$uid,$tagtype="1")
{
$dbobj=new dboperations();
$uiobj=new uifriend();
$tagid=$uiobj->randomstring(30,DB_SOCIAL,SOCIAL_TAG,tag_tagid);
$c=0;
foreach($tagarray as $tags)
{
$c++;
$tagname=$tags["tagname"];
$taguid=$tags["tagid"];
$dbobj->dbinsert("INSERT INTO ".SOCIAL_TAG." (".tag_tagid.",".tag_fuid.",".tag_tuid.",".tag_tagname.",".tag_tagtype.") VALUES
('$tagid','$uid','$taguid','$tagname','$tagtype')",DB_SOCIAL);
}
if($c==0)
{
$lasterror="No tags were added";return "";
}
else
{
return $tagid;
}
}
Here, if i call a error handling function instead of monitoring the variable, it wont be advisable in my case since the error handling function may do any operation like give alert and redirect to a page or any similar operation.
I asked this question cause, i thought what if the script does not reach the line
return "";
It would affect the project's workflow. Thats what i am worried about.
And the variable i was talking about is $lasterror and i have many functions like this where $lasterror is used.
I saw this, so I built this:
https://github.com/leedavis81/vent
Should solve your problem.
There is no built-in way to do this in PHP, and there's no easy way to add it. It doesn't really feel right for the way the language works anyway.
Instead of setting a variable, you could build a custom function that handles the error - or use PHP's built-in error handling functionality using a custom error handler.
Another error handling method which comes close to what you want to do (I think) is exceptions.
I want clear $_POST array content fully, all examples what I see in internet, looks like this:
if (count($_POST) > 0) {
foreach ($_POST as $k=>$v) {
unset($_POST[$k]);
}
}
Tell please, this variant will be not more better? (Point of view as saving resources)
if (count($_POST) > 0) {
$_POST = array();
}
or not ?
Yes, that is fine. $_POST is just another variable, except it has (super)global scope.
$_POST = array();
...will be quite enough. The loop is useless. It's probably best to keep it as an array rather than unset it, in case other files are attempting to read it and assuming it is an array.
To unset the $_POST variable, redeclare it as an empty array:
$_POST = array();
The solutions so far don't work because the POST data is stored in the headers. A redirect solves this issue according this this post.
How to delete $_POST variable upon pressing 'Refresh' button on browser with PHP?
It may appear to be overly awkward, but you're probably better off unsetting one element at a time rather than the entire $_POST array. Here's why: If you're using object-oriented programming, you may have one class use $_POST['alpha'] and another class use $_POST['beta'], and if you unset the array after first use, it will void its use in other classes. To be safe and not shoot yourself in the foot, just drop in a little method that will unset the elements that you've just used: For example:
private function doUnset()
{
unset($_POST['alpha']);
unset($_POST['gamma']);
unset($_POST['delta']);
unset($_GET['eta']);
unset($_GET['zeta']);
}
Just call the method and unset just those superglobal elements that have been passed to a variable or argument. Then, the other classes that may need a superglobal element can still use them.
However, you are wise to unset the superglobals as soon as they have
been passed to an encapsulated object.
You can use a combination of both unset() and initialization:
unset($_POST);
$_POST = array();
Or in a single statement:
unset($_POST) ? $_POST = array() : $_POST = array();
But what is the reason you want to do this?
To answer "why" someone might use it, I was tempted to use it since I had the $_POST values stored after the page refresh or while going from one page to another. My sense tells me this is not a good practice, but it works nevertheless.
I have a php script which can take some GET params. I would like to know how I can call the script with a different param inside the script.
I want to achieve something like this:
if ($param == "authorise") {
//call the same script but use the $param, getAccountDetails"
i.e http://mywebsite.com/?param=getAccountDetails&var=ivar&foo=bar
}
You could just modify the $_GET array at the top of the script depending on what's inside it:
if(isset($_GET['authorise'])){
$_GET['do_some_secret_thing'] = 'whatever';
}
// run the rest of your logic LIKE A BOSS.
There might be some more wizardy way of doing it, but that'd work and is fairly straightforward.
Good luck!
Use sessions
http://php.net/manual/en/features.sessions.php
sessions are used to add information to the client so they can be retrieved later.
The simplest thing I can think of would be to redirect the user to the script with the new GET variable.
if( $_GET['abc'] == 1 ) {
header( 'Location: '.$_SERVER['PHP_SELF'].'?abc=2' );
}
If you would like to do this without exiting the running PHP script, take a look at cURL.