php string manipulation received by url after installing facebook app - php

I get this string from URL after installing a facebook page app on several pages.
tabs_added[255408179646]=1&tabs_added[197573531148]=1&tabs_added[225556742602]=1&tabs_added[201931451540]=1&tabs_added[205657687417]=1
I am looking for a way to itterate and be able to loop and echo each numeric value within brackets [].

The values are stored in $_GET['tabs_added'], and you can access them like this:
$tabs_added = $_GET['tabs_added'];
foreach($tabs_added as $key => $value){
echo $key;
}
You should probably check if the values are present with if(isset($_GET['tabs_added'])) first.

The array should be stored in $_GET['tabs_added']. So you can try something like this to loop through it;
foreach($_GET['tabs_added'] AS $key => $value)
{
echo $key;
}

parse_str is made for parsing query strings.
parse_str('tabs_added[255408179646]=1&tabs_added[197573531148]=1', $parsed);
var_dump($parsed);

You can get an array of tabs through either the $_GET or $_POST superglobal variable, depending on whether this is a GET or POST request.
$tabs = $_GET["tabs_added"]; // or $_POST['tabs_added'];
foreach($tabs as $k => $v) {
echo $k;
}
You can also check if the param is present first to avoid an Undefined Index Notice for $_GET["tabs_added"]; and subsequent Invalid argument Warning passing NULL to the foreach loop.
isset($_GET['tabs_added']

Related

foreach $key variable clarification

I have this code
if (isset($_POST['submit2']))
{
foreach ($_POST['check_list'] as $key) {
$input = implode(",", $key);
}
} /*end is isset $_POST['submit2'] */
echo $input;
it produces the error " implode(): Invalid arguments passed " when I change the implode arguments to implode(",", $_POST['check_list']) it works as intended.
Can someone clarify why? As far as I understand the $key variable should be the same as the $_POST['submit2'] isn't that what the as in the foreach does?
Sorry if it's a silly question, I'm self taught and sometimes details like that are hard to find online.
You seem confused at several levels, so let me clarify some of them:
You said 'As far as I understand the $key variable should be the same as the $_POST['submit2'] isn't that what the as in the foreach does?'. The answers are NO and NO:
The $key variable outside the foreach loop will contain the last element of the array that's stored in $_POST['check_list'], $_POST['submit2'] seems to be only used to check if is set and nothing else in your piece of code. What foreach does is to traverse any iterator variable (an array in your case) and set the current item in a variable ($key) in your case. So after the loop, $key will contain the last element of that array. For more information refer to the docs: [http://php.net/manual/en/control-structures.foreach.php]
implode expects the second parameter to be an array, it seems you're not providing an array, but any other type. Is the last item of $_POST['check_list'] actually an array?
If you're trying to 'glue' together all items of $_POST['check_list'], you don't need to iterate, you just use implode on that one: $input = implode(",", $_POST['check_list']);. Otherwise, i'm not sure what are you trying to do.
Maybe if you explain what are you trying to do, we can help better.
Foreach already iterates trough your values. You can either get the value and echo it from there or you can add it to another array input if thats what you need:
if (isset($_POST['submit2']))
{
foreach ($_POST['check_list'] as $key => $value) {
$input[] = 'Value #'. $key .' is ' . $value;
}
}
echo implode(",", $input);
You are saying that $_POST['check_list'] is an array if implode() works on it, so no need to loop to get individual items. To implode() the values:
echo implode(',', $_POST['check_list']);
To implode() the keys:
echo implode(',', array_keys($_POST['check_list']));
foreach() iterates over an array to expose each item and get the individual values and optionally keys one at a time:
foreach($_POST['check_list'] as $key => $val) {
echo "$key = $value<br />";
}
implode function needs array as second argument. You are passing string value as second argument. That's why it's not working.

PHP post all form inputs without creating variables for each

Usually when I use PHP I create a variable and post statement for each form input like so:
$myVar1 = $_POST["formItem1"];
$myVar2 = $_POST["formItem2"];
ect......
I know if i use:
echo $_POST;
I can get all the key and values from the form inputs but I don't know how to use them in a script.
So I guess I have 2 questions:
How do I quickly post all form inputs without creating a variable for each input?
How do I use a posted in a script without having it assigned to a specific variable?
To simply echo all the inputs, you can use a foreach loop:
foreach ($_POST as $key => $value) {
echo $value.'<br/>';
}
If you don't want to store them in variables, use arrays:
$data = array();
foreach ($_POST as $key => $value) {
$data[] = $value;
}
Now, $data is an array containing all the data in $_POST array. You can use it however you wish.
You don't have to assign to a variable. You can use directly $_POST['input_name']
If you want to deal with each sended params, you can use foreach loop:
foreach ($_POST as $key => $val)
{
echo "$key : $val <br/>";
}
for this instance of just quickly checking and testing i typically just use the print_r() function: documentation here
as quoted from the docs:
print_r() displays information about a variable in a way that's readable by humans.
one line easy to toggle on and off (with comments)- no need to use any form of variables
print_r($_POST);
if i need my output nice and readable i like to expand it as follows:
function print_r2($x){
echo '<pre>';
print_r($x);
echo '</pre>';
}
and then you can call with: print_r2($_POST);
this way you get the pre-formatted text block on your html page and can see the line breaks and tabbed spacing provided from the $_POST object printout
Another way to extract (besides the extract function) variables is;
$array = array('foo'); // Which POST variables do you want to get
foreach($array as $key) {
if(!isset(${$key})) { // Check if variable hasn't been assigned already
${$key} = $_POST[$key];
}
}
echo $foo;
I would not recommend it because it can get quite messy to keep up.
View everything in $_POST is useful for debugging
echo '<pre>'.print_r($_POST, true).'</pre>';
Access a specific checkbox
HTML
<input type="checkbox" value="something" name="ckbox[]" checked>
<input type="checkbox" value="anotherthing" name="ckbox[]" checked>
PHP
echo $_POST['ckbox'][0]; // something
echo $_POST['ckbox'][1]; // anotherthing
// isolate checkbox array
$ckbox_array = $_POST['ckbox'];
Define a function that allows you to access a specific $_POST item by name (key):
function get_post_value($name, $default)
{
if ( isset($_POST[$name]) ) {
return $_POST[$name];
} else if ( $default ) {
return $default;
}
return null;
}
$default allows you to pass a value that can be used as a fallback if the key you specify isn't present in the $_POST array.
Now you can reference $_POST items without assigning them to a variable, and without worrying if they are set. For example:
if ( get_post_value('user-login-submit', false) ) {
// attempt to log in user
}
You can use extract($_POST), it will create variables for you.
For example, you can have for the code you posted :
<?php
$_POST["formItem1"] = "foo";
extract($_POST);
echo $formItem1; // will display "foo"
?>
EDIT : it's not PHP explode, it's extract.

Calling PHP function in itself

In the following script function clean($data) calls it within it, that I understand but how it is cleaning data in the statement $data[clean($key)] = clean($value);??? Any help is appreciated.. I am trying to figure it out as I am new to PHP. Regards.
if (ini_get('magic_quotes_gpc')) {
function clean($data) {
if (is_array($data)) {
foreach ($data as $key => $value) {
$data[clean($key)] = clean($value);
}
} else {
$data = stripslashes($data);
}
return $data;
}
$_GET = clean($_GET);
$_POST = clean($_POST);
$_REQUEST = clean($_REQUEST);
$_COOKIE = clean($_COOKIE);
}
Your Question:
So if I undertsand correctly you want to know what is the function doing in the line
$data[clean($key)] = clean($value);
The Answer:
See the prime purpose of the function is to remove slashes from string with php's stripslashes method.
If the input item is an array then it tries to clean the keys of the array as well as the values of the array by calling itself on the key and value.
In php arrays are like hashmaps and you can iterate over the key and value both with foreach loop like following
foreach ($data as $key => $value) {....}
So if you want to summarize the algorithm in your code snippet it would be as under
Check if the input is array. If it is not then go to step 4
For each item of array clean the key and value by calling clean method on it (Recursively)
Return the array
clean the input string using stripslashes method
5 return the cleaned input
From my understanding it's not cleaning the key but creates a new element with a clean key while the uncleaned key remains.
$a['foo\bar'] : val\ue
becomes
$a['foo\bar'] : val\ue
$a['foobar'] : value
Someone correct me if im wrong.
Maybe you'll understand the code better if it's put this way:
foreach ($data as $key => $value) {
$key = clean($key); // Clean the key, the
$value = clean($value); // Clean the value
$data[$key] = $value; // Put it in the array that will be returned
}
Assuming you have an array like this:
$_POST = array(0 => 'foo', 1 => array('bar' => 'baz'));
the following will happen:
Call clean($_POST);
call clean 0
call clean 'foo'
$return[0] = 'foo'
call clean 1
call clean 'bar'
call clean 'baz'
$return[1] = array('bar' => 'baz');
You should probably read this: http://www.codewalkers.com/c/a/Miscellaneous/Recursion-in-PHP/
The main purpose of the function is to clean an associative array or a single variable. An associative array is an array where you define keys and values for that keys; so are special arrays used in PHP like $_GET $_POST and so on.
The meaning of "cleaning" is to check whether magic quotes are active - this causes some characters in these arrays to be escaped with backslashes when you post dynamic data to a PHP page.
$_GET["Scarlett"] = "O' Hara" becomes with magic quotes $_GET["Scarlett"] = "O\' Hara"
So if magic quotes are active, the function takes care of this, and slashes are stripped so that the strings retain their correct, not escaped value.
The algorithm checks if the data passed to the function is an array, if not it cleans directly the value.
$string = "Escapes\'in\'a string";
clean($string);
is it an array? No. Then return stripslashes(my data)
$array = array("key\'with\'escapes"=>"value\'with\'escapes", "another\'key"=>"another value");
clean($array)
is it an array? Yes. So cycle through each key/value pair with foreach, take the key and clean it like the first example; then take the value and do the same and put the cleaned versions in the array.
As you see the function has two different behaviours differentiated by that "if" statement.
If you pass an array, you activate the second behaviour that in turns passes couples of strings, not arrays, triggering the first behaviour.
My thought is that this function doesn't work properly, though. Anyone got the same sensation? I have it not tested yet but it seems it's not "cleaning" the key/values in the sense of replacing them, but adds the cleaned versions along the uncleaned ones.

using a foreach loop to initialize variables

I have built an empty associative array whos keynames refer to submitted post data. I can capture the postdata just fine, but I run into trouble trying to instantiate variables who's names match the array key.
for example:
$insArray = array('rUsername'=>'', 'rPass'=>'', 'rQuestion'=>'', 'rAnswer'=>'', 'rFName'=>'', 'rLName'=>'', 'rBDateD'=>'', 'rBDateM'=>'', 'rBDateY'=>'', 'rHCheck'=>'', 'rHCeckOption'=>'', 'rEmail'=>'');
foreach($insArray as $key=>$value){
if (filter_input(INPUT_POST, $key) != ''){
$key = stripslashes(filter_input(INPUT_POST, $key));
$insArray[$key] = $key;
}
}
First line creates the empty array, then the foreach loops through this array. Now it gets tricky.
filter_input(INPUT_POST, $key) captures the value located in the post data matching the current key, rUsername in this case
$key is where the problem lies. I want the NAME of the new variable to be the associative key name, for example I want to replace $key with $rUsername in the first iteration, $rPass in the second, and so on. I tried using two $$, but I know that's not right. Never tried doing this before, but it would be helpful if I could figure it out.
UPDATE:
This is the final code which was a combination of two of the answers provided.
if (isset($_POST['submit'])) {
//Build array of variables to be put into database
$insArray = array('rUsername'=>'', 'rPassword'=>'', 'rQuestion'=>'', 'rAnswer'=>'', 'rFName'=>'', 'rLName'=>'', 'rBDateD'=>'', 'rBDateM'=>'', 'rBDateY'=>'', 'rHCheck'=>'', 'rHCheckOption'=>'', 'rEmail'=>'');
foreach(array_keys($insArray) as $key){
$insArray[$key] = filter_input(INPUT_POST, $key);
$$key = filter_input(INPUT_POST, $key);
}
}
Gave me exactly the output I wanted, thanks guys!
You're not accessing $_POST at all, so all you're doing is taking some array members you defined yourself, filtering them for harmful POST characters (why would you attempt to inject your own code?) and then creating a new array from those self-defined key values.
If I'm guessing right at what you want, it should be this:
foreach(array_keys($insArray) as $key) {
$insArray[$key] = stripslashes(filter_input(INPUT_POST, $_POST[$key]));
}
The use of stripslashes suggests that you're on a braindead version of PHP which has magic_quotes enable. You should upgrade to a modern version of PHP and/or turn them off.
The solution is change
$key = stripslashes(filter_input(INPUT_POST, $key));
to
$$key = stripslashes(filter_input(INPUT_POST, $key));
See http://www.php.net/manual/en/language.variables.variable.php
Also, recheck your code, which are doing some mistakes..
If I understand you correctly, Im going to suggest this approach:
$defaultValues = array('rUsername'=>'', 'rPass'=>'', 'rQuestion'=>'', 'rAnswer'=>'', 'rFName'=>'', 'rLName'=>'', 'rBDateD'=>'', 'rBDateM'=>'', 'rBDateY'=>'', 'rHCheck'=>'', 'rHCeckOption'=>'', 'rEmail'=>'');
$values = array_map('stripslashes', array_merge($defaultValues, array_filter($_POST)));
extract($values, EXTR_SKIP);
echo $rUsername;
echo $rPass;
.........
By using the snippet above, you have to take into account the following
Im using the extract function with EXTR_SKIP so you dont overwrite existing variables. Make sure to only use the variables you need in your code and sanitize them appropietly.
By using array_filter on the $_POST superglobal im "erasing" all empty or null variables. so if an expected key was not sent via $_POST, it defaults to the value specified by the $defaultValues array.
I dont quite understand why you are using filter_input without the third parameter (filter constants).
Hope this will help, If not may be I have misunderstood the problem.
Instead of
$key = stripslashes(filter_input(INPUT_POST, $key));
$insArray[$key] = $key;
Try
$insArray[$key] =stripslashes(filter_input(INPUT_POST, $key));
Then after the foreach loop
extract($insArray);

A $_GET input parameter that is an Array

I'm trying to pass 3 parameter to a script, where the 3rd parameter $_GET['value3'] is supposed to be an array
$_GET['value1']
$_GET['value2']
$_GET['value3'] //an array of items
I'm calling the script like this: (notice my syntax for value3, I'm not sure it's correct)
http://localhost/test.php?value1=test1&value2=test2&value3=[the, array, values]
I then use a foreach to hopefully loop through the third parameter value3 which is the array
//process the first input $_GET['value1']
//process the second input $_GET['value2']
//process the third input $_GET['value3'] which is the array
foreach($_GET['value3'] as $arrayitem){
echo $arrayitem;
}
but I get the error Invalid argument supplied for foreach()
I'm not sure if my methodology is correct. Can some clarify how you'd go about doing the sort of thing
There is no such thing as "passing an array as a URL parameter" (or a form value, for that matter, because this is the same thing). These are strings, and anything that happens to them beyond that is magic that has been built into your application server, and therefore it is non-portable.
PHP happens to support the &value3[]=the&value3[]=array&value3[]=values notation to automagically create $_GET['value3'] as an array for you, but this is special to PHP and does not necessarily work elsewhere.
You can also be straight-forward and go for a cleaner URL, like this: value3=the,array,values, and then use explode(',', $_GET['value3']) in your PHP script to create an array. Of course this implies that your separator char cannot be part of the value.
To unambiguously transport structured data over HTTP, use a format that has been made for the purpose (namely: JSON) and then use json_decode() on the PHP side.
try
http://localhost/test.php?value1=test1&value2=test2&value3[]=the&value3[]=array&value3[]=values
For arrays you need to pass the query parameters as
value3[]=abc&value3[]=pqr&value3[]=xyz
You can cast the name of the index in the string too
?value1[a]=test1a&value1[b]=test1b&value2[c][]=test3a&value2[c][]=test3b
would be
$_GET['value1']['a'] = test1a
$_GET['value1']['b'] = test1b
$_GET['value2']['c'] = array( 'test3a', 'test3b' );
http://php.net/manual/en/reserved.variables.get.php
Check out the above link..
You will see how the GET method is implemented.
What happens is that the URL is taken, it is delimited using '&' and then they are added as a key-value pair.
public function fixGet($args) {
if(count($_GET) > 0) {
if(!empty($args)) {
$lastkey = "";
$pairs = explode("&",$args);
foreach($pairs as $pair) {
if(strpos($pair,":") !== false) {
list($key,$value) = explode(":",$pair);
unset($_GET[$key]);
$lastkey = "&$key$value";
} elseif(strpos($pair,"=") === false)
unset($_GET[$pair]);
else {
list($key, $value) = explode("=",$pair);
$_GET[$key] = $value;
}
}
}
return "?".((count($_GET) > 0)?http_build_query($_GET).$lastkey:"");
}
Since, they are added as a key-value pair you can't pass array's in the GET method...
The following would also work:
http://localhost/test.php?value3[]=the&value3[]=array&value3[]=values
A more advanced approach would be to serialize the PHP array and print it in your link:
http://localhost/test.php?value3=a:3:{i:0;s:3:"the";i:1;s:5:"array";i:2;s:6:"values";}
would, essentially, also work.

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