Create php variable from HTML post name and value - php

I have a large HTML form posting many fields to a PHP page. I'm assigning all those fields to PHP variables one by one. Is there a way to put to create a function to auto assign the POST value to a PHP variable?
This is my code now:
if (!empty($_POST["x"])) {
$x = clean_post($_POST["x"]); }
if (!empty($_POST["y"])) {
$y = clean_post($_POST["y"]);
}?>
Thanks!

You can do this using the array_keys() function and a foreach-loop like this:
foreach (array_keys($_POST) as $key) {
${$key} = $_POST[$key];
}
But why not use the $_POST array in the first place?

Yes, but it's a rubbish idea. They actually had this in PHP, but removed it. It was called register_globals. So for instance, $_POST['name'] would automatically have $name created.
If you insist on this terrible idea, you should be able to do it like this:
foreach ($_POST as $key => $value) {
$$key = $value;
}
Don't do it though! Read this for more info https://secure.php.net/manual/en/security.globals.php

Related

Foreach loop that loops through $_POST data instead of static isset($_POST["name"]......)

So here I am again trying to find better ways of doing things. 90% of tutorials do things the normal way below:
if (isset($_POST['name']) && isset($_POST['password'])) {
// Does some stuff...
}
It is fine but it does seem too static since I prefer something far more dynamic. For example lets say looping through all $_POST arrays within a contact form. This way I can change the name or the fields to whatever I want or add more...my code will always handle the rest.
I know a foreach loop would come in handy but, as someone new to the world of programming and php I thought you could show me how something like this is done. So how do I replace the above with a for loop? I am not sure where to start.
try this:
$check=true;
if(isset($_POST)){
foreach($_POST as $key=>$value){
if(!isset($_POST[$key]){
$check = false;
break;
}
}
}
based on $check you can verify if it was properly sent or not.
Another approach is to have a sort of verification because it is possible you might not get the key in $_POST
$keys =array("input1","input2");
$check=true;
if(isset($_POST)){
foreach($keys as $input){
if(!array_key_exists($input,$_POST)){
$check = false;
break;
}
}
}
Well you could try something like this :-
<?php
$inputNames = array("input1","input2");
foreach($inputNames as $input)
{
if (isset($_POST["$input"]) && isset($_POST["$input"])) {
// Does some stuff...
}
}
?>
Make an array with the names of all your input tags, and then simply do a foreach between them. In this way, you always only need to edit the names array.
You can always use foreach loop like that:
foreach($_POST as $key => $value){ echo '$_POST["'.$key.'"] = "'.$value.'"'}
But remember, that anyone, can modify your form, prepare some post statement and send data that can create little mess with your code. So it`s good way to validate all fields.
Dynamic validation is of course possible, but you need to do it right!

Naming variables automatically from $_POST array.

My PHP script processes some POST variables.
Instead of manually naming each variable
$name = $_POST['name'];
$email = $_POST['account'];
I'd like my script to grab all the variable names from the $_POST array and automatically create variables with those names, e.g. (not code, just illustrating the principle)
foreach ($_POST as $name => $value) {
$[$name] = $value;
}
Is something like that possible?
You can use the extract function for this. But there is a risk, because you cannot know what data is posted, and it will create or overwrite variables in the scope in which you call it, possibly leading to unexpected behaviour.
You can partially counter this, using one of the flags for extract, for instance:
extract($_POST, EXTR_SKIP);
Anyway, make sure to read the two warnings (red block) on the documentation page of this function. And of course, the same warning applies when you do this using your own foreach loop, so answers suggesting that are no more secure.
There is extract function in php:
extract($_POST);
This is a very bad idea because it allows a user to create any variable in your PHP script (within the scope that it this code is used). Take for example if you have a $debugging flag:
$debugging = false;
foreach ($_POST as $name => $value) {
$$name = $value;
}
// some time later, we do a query and output the SQL if debugging
if($debugging){
echo $sql;
}
What if a malicious user submitted an input called debugging with a value of 1? Your debugging flag would be changed and the user could see sensitive debug data.
Try this (which is a bad practice):
foreach ($_POST as $name => $value) {
$$name = $value;
}
You can do this with variable variables as follows:
foreach ($_POST as $name => $value) {
$$name = $value;
}
You can also use the following format if you want to muck about with the variable names some more:
foreach ($_POST as $name => $value) {
${$name.'_1'} = $value;
}
There are comments here saying don't use variable variables - mainly because they are hard as heck to troubleshoot, make it damn hard for others to read your code and will (for the most part) create more headaches than they solve.

Process form fields with foreach loop on posting form?

I'm posting 20 results from a form, to be used on the next page, is there a quick foreach way of posting:
$UserID1 = $_POST['UserID1'];
Where the ID changes each time rather than listing it 20 odd times? I thought a foreach statement, but i'm not too sure where to begin with it?
You can use extract():
extract($_POST);
echo $UserID1; // This now works
This is not considered a good programming practice but will do what you want.
The other answers will do the job just fine, however they introduce security issues.
Code such as:
foreach($_POST as $key => $value){
$$key = $value; //Assign the value to a variable named after $key
}
Allows me to post any form field I wish to your page and alter any variables value, for example, say you have code something like this elsewhere:
if ($validation) { // Do something }
Then I am able to post a form field named validation with a value of 1 and manipulate your code as that would assign a variable called $validation to a value of my choosing.
Using that code to assign variables from all your $_POST values automatically, is the same as using register_globals which was deprecated due to it's blatent security issues. See: http://www.php.net/manual/en/security.globals.php
If you must do this, you must check that the posted values are something that you expect. For example, check for the existance of UserID. This will only allow the creation of variables if they begin with UserID:
foreach($_POST as $key => $value) {
if (substr($key, 0, 6) == 'UserID') {
$$key = $value; //Assign the value to a variable named after $key
}
}
This will check for $_POST['UserID1'] and create $UserID1 and $_POST['UserID2'] and create $UserID2...
foreach($_POST as $key => $value){
$$key = $value; //Assign the value to a variable named after $key
}

Put all parameters from a session into variables

I have the following code:
if(isset($_SESSION["spgrund"])) {
$spgrund = $_SESSION["spgrund"];
}else{
$spgrund = '';
}
This code is repeated about 20 times for each session variable. How can I make a loop out of it?
foreach($_SESSION as $key => $value){
$$key = $value;
}
I think that should work. But I get undefined variable error messages. Can't I use such a loop?
What you actually try to achieve is already available in PHP, the extract­Docs function:
extract($_SESSION);
From it's documentation:
Import variables from an array into the current symbol table.
Checks each key to see whether it has a valid variable name. It also checks for collisions with existing variables in the symbol table.
You would still need look for undefined variables however. Probably you should define them first?
foreach($_SESSION as $key => $value)
{
$$key = $value;
}
you missed the $ for value

Any easier way to do $name = $_REQUEST["name"];?

So I'm new to PHP and am trying to create a form. I accept a bunch of parameters and want to process them in the same page. I'm not sure how to do this without a giant if-else containing the entire page as if($_POST). This doesn't seem ideal.
In addition, I'm finding that I do the following a lot. Is there any way to shorten this? The names all remain the same.
$name = $_REQUEST["name"];
$gender = $_REQUEST["gender"];
$age = $_REQUEST["age"];
And I have a lot of lines which are just doing that, and it seems terribly inefficient
You can use the extract() function to do that. But it has a security downside: existing variables can be overwritten if someone would add variables to the POST header.
Edit: hsz's solution is better
What process you are doing with if..else..if you have to post the code so that we can let you know how that can be shorten.
you can avoid the assignment for each variable using extract function.
extract($_POST);
But be aware that can overwrite your existing variable if the are named same as your input controls.
Stop using $_REQUEST, because it is a combination of $_COOKIE , $_POST and $_GET.
It becomes a security risk.
Instead of using $_REQUEST you should use $_POST here.
$keys = array('name', 'gender', 'age');
foreach ( $keys as $key ) {
if ( isset($_POST[$key]) ) {
$$key = $_POST[$key];
}
// optional:
else {
$$key = ''; // default value
}
}
Magic quotes? http://php.net/manual/en/security.magicquotes.php
For the first thing: Turn it around. Don't do
if ($_POST) {
// Your handling code
} else {
echo "No data!";
}
do
if (!$_POST) {
die("No data!");
}
// Your handling code
You can use extract(), however, this means that you're bringing in a lot of variables that you (might not know about) int your current scope.
My suggestion would be to loop through your array and do something with the variables in there (e.g. - validation)
foreach ($_POST as $key => $valu) {
//do something with the variables
}
Also, don't use $_REQUEST unless you really want to check $_GET, $_POST and $_COOKIE. Use the proper array when accessing variables or people can send data you don't expect.

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