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PHP : Language Reference : Variables : Variables from outside PHP

Variables from outside PHP

HTML Forms (GET and POST)

When a form is submitted to a PHP script, the information from that form is automatically made available to the script. There are many ways to access this information, for example:

Example 3.9. A simple HTML form

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<form action="foo.php" method="post">
   Name:  <input type="text" name="username" /><br />
   Email: <input type="text" name="email" /><br />
   <input type="submit" name="submit" value="Submit me!" />
</form>


Depending on your particular setup and personal preferences, there are many ways to access data from your HTML forms. Some examples are:

Example 3.10. Accessing data from a simple POST HTML form

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<?php
// Available since PHP 4.1.0

  echo $_POST['username'];
  echo $_REQUEST['username'];

  import_request_variables('p', 'p_');
  echo $p_username;

// Available since PHP 3. As of PHP 5.0.0, these long predefined
// variables can be disabled with the register_long_arrays directive.

  echo $HTTP_POST_VARS['username'];

// Available if the PHP directive register_globals = on. As of
// PHP 4.2.0 the default value of register_globals = off.
// Using/relying on this method is not preferred.

  echo $username;
?>


Using a GET form is similar except you'll use the appropriate GET predefined variable instead. GET also applies to the QUERY_STRING (the information after the '?' in a URL). So, for example, http://www.example.com/test.php?id=3 contains GET data which is accessible with $_GET['id']. See also $_REQUEST and import_request_variables().

Note:

Superglobal arrays, like $_POST and $_GET, became available in PHP 4.1.0

As shown, before PHP 4.2.0 the default value for register_globals was on. And, in PHP 3 it was always on. The PHP community is encouraging all to not rely on this directive as it's preferred to assume it's off and code accordingly.

Note:

The magic_quotes_gpc configuration directive affects Get, Post and Cookie values. If turned on, value (It's "PHP!") will automagically become (It\'s \"PHP!\"). Escaping is needed for DB insertion. See also addslashes(), stripslashes() and magic_quotes_sybase.

PHP also understands arrays in the context of form variables (see the related faq). You may, for example, group related variables together, or use this feature to retrieve values from a multiple select input. For example, let's post a form to itself and upon submission display the data:

Example 3.11. More complex form variables

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<?php
if ($_POST) {
   echo '<pre>';
   echo htmlspecialchars(print_r($_POST, true));
   echo '</pre>';
}
?>
<form action="" method="post">
   Name:  <input type="text" name="personal[name]" /><br />
   Email: <input type="text" name="personal[email]" /><br />
   Beer: <br />
   <select multiple name="beer[]">
       <option value="warthog">Warthog</option>
       <option value="guinness">Guinness</option>
       <option value="stuttgarter">Stuttgarter Schwabenbräu</option>
   </select><br />
   <input type="submit" value="submit me!" />
</form>


In PHP 3, the array form variable usage is limited to single-dimensional arrays. As of PHP 4, no such restriction applies.

IMAGE SUBMIT variable names

When submitting a form, it is possible to use an image instead of the standard submit button with a tag like:

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<input type="image" src="image.gif" name="sub" />

When the user clicks somewhere on the image, the accompanying form will be transmitted to the server with two additional variables, sub_x and sub_y. These contain the coordinates of the user click within the image. The experienced may note that the actual variable names sent by the browser contains a period rather than an underscore, but PHP converts the period to an underscore automatically.

HTTP Cookies

PHP transparently supports HTTP cookies as defined by » Netscape's Spec. Cookies are a mechanism for storing data in the remote browser and thus tracking or identifying return users. You can set cookies using the setcookie() function. Cookies are part of the HTTP header, so the SetCookie function must be called before any output is sent to the browser. This is the same restriction as for the header() function. Cookie data is then available in the appropriate cookie data arrays, such as $_COOKIE, $HTTP_COOKIE_VARS as well as in $_REQUEST. See the setcookie() manual page for more details and examples.

If you wish to assign multiple values to a single cookie variable, you may assign it as an array. For example:

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<?php
 setcookie("MyCookie[foo]", 'Testing 1', time()+3600);
 setcookie("MyCookie[bar]", 'Testing 2', time()+3600);
?>

That will create two separate cookies although MyCookie will now be a single array in your script. If you want to set just one cookie with multiple values, consider using serialize() or explode() on the value first.

Note that a cookie will replace a previous cookie by the same name in your browser unless the path or domain is different. So, for a shopping cart application you may want to keep a counter and pass this along. i.e.

Example 3.12. A setcookie() example

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<?php
if (isset($_COOKIE['count'])) {
   $count = $_COOKIE['count'] + 1;
} else {
   $count = 1;
}
setcookie('count', $count, time()+3600);
setcookie("Cart[$count]", $item, time()+3600);
?>


Dots in incoming variable names

Typically, PHP does not alter the names of variables when they are passed into a script. However, it should be noted that the dot (period, full stop) is not a valid character in a PHP variable name. For the reason, look at it:

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<?php
$varname.ext;  /* invalid variable name */
?>

Now, what the parser sees is a variable named $varname, followed by the string concatenation operator, followed by the barestring (i.e. unquoted string which doesn't match any known key or reserved words) 'ext'. Obviously, this doesn't have the intended result.

For this reason, it is important to note that PHP will automatically replace any dots in incoming variable names with underscores.

Determining variable types

Because PHP determines the types of variables and converts them (generally) as needed, it is not always obvious what type a given variable is at any one time. PHP includes several functions which find out what type a variable is, such as: gettype(), is_array(), is_float(), is_int(), is_object(), and is_string(). See also the chapter on Types.

Code Examples / Notes » language.variables.external

nospam
you can convert old code to work with register_globals=off without sacrificing security.  Or maybe you like working with variables the old way better.  I know I do!
I looked all over for something like this so here it is:
$expected=array(
'name', // Only accept these variables from a submit!
'email',
'favorite_color'
); for ($i=0;$i < count($expected);$i++)
$$expected[$i] = (isset($_GET[$expected[$i]]))?$_GET[$expected[$i]]:NULL;
// This is a test.
echo "Name: $name
";
echo "Email: $email
";
echo "Fav. Color: $favorite_color
";

vierubino dot r3m0ofdisb1t
When you are using checkboxes to submit multiple choices, there is no need to use the complex method further down the page where you assign a unique name to each checkbox.
Instead, just name each checkbox as the same array, e.g.:
<input type="checkbox" name="items[]" value="foo" />
<input type="checkbox" name="items[]" value="bar" />
<input type="checkbox" name="items[]" value="baz" />
This way your $_POST["items"] variable will return as an array containing all and only the checkboxes that were clicked on.

lennynyktyk
When dealing with multiple select boxes and the name=some_name[] so that PHP will understand that is needs to interpet the input as an array an not as a single value. If you want to access this in Javascript you should assign an id attribute to the select box as well as the name attribute. Then proceed to use the id attribute in Javascript to reference the select box and the name attribute to reference the select box in PHP.
Example
<select multiple id="select_id" name="select_name[]">
....
</select>
<?PHP
   echo $select_name[0];
?>
<script language="javascript">
 document.forms[0].select_id.options[0].selected = true;
</script>
I hope you get the idea

arjini
When dealing with form inputs named_like_this[5] and javascript, instead of trying to get PHP to do something fancy as mentioned below, just try this on the javascript side of things:
<form name="myForm">
<script>
my_fancy_input_name = 'array_of_things[1]';
/* now just refer to it like this in the dom tree
document[myForm][my_fancy_input_name].value
etc*/
</script>
<input type="text" name="array_of_things[1]" value="1"/>
</form>
No fancy PHP, in fact, you shouldn't need to change your PHP at all.

steiner277
When accessing variables from a post, do NOT put $_POST['fieldname'] in double quotes or you will get an error message.
e.g. the following works fine:
$msg = "The message is:\t" . $_POST['message'] . "\n";
but the following will cause errors:
$msg = "The message is:\t$_POST['message']\n";

tmk-php
To handle forms with or without [] you can do something like this:
function repairPost($data) {
// combine rawpost and $_POST ($data) to rebuild broken arrays in $_POST
$rawpost = "&".file_get_contents("php://input");
while(list($key,$value)= each($data)) {
$pos = preg_match_all("/&".$key."=([^&]*)/i",$rawpost, $regs, PREG_PATTERN_ORDER);
if((!is_array($value)) && ($pos > 1)) {
$qform[$key] = array();
for($i = 0; $i < $pos; $i++) {
$qform[$key][$i] = urldecode($regs[1][$i]);
}
} else {
$qform[$key] = $value;
}
}
return $qform;
}
// --- MAIN
$_POST = repairPost($_POST);
The function will check every field in the $_POST with the raw post data and rebuild the arrays that got lost.

jlratwil
To get multiple selected (with "multiple" ) lists in <select> tag, make sure that the "name" attribute is added to braces, like this:
<select multiple="multiple" name="users[]">
    <option value="foo">Foo</option>
    <option value="bar">Bar</option>
</select>
When submitted to PHP file (assume that you have a complete form) it will return an array of strings. Otherwise, it will just return the last element of the <select> tag you selected.

krydprz
This post is with regards to handling forms that have more than one submit button.
Suppose we have an HTML form with a submit button specified like this:
<input type="submit" value="Delete" name="action_button">
Normally the 'value' attribute of the HTML 'input' tag (in this case "Delete") that creates the submit button can be accessed in PHP after post like this:
<?
$_POST['action_button'];
?>
We of course use the 'name' of the button as an index into the $_POST array.
This works fine, except when we want to pass more information with the click of this particular button.
Imagine a scenario where you're dealing with user management in some administrative interface.  You are presented with a list of user names queried from a database and wish to add a "Delete" and "Modify" button next to each of the names in the list.  Naturally the 'value' of our buttons in the HTML form that we want to display will be "Delete" and "Modify" since that's what we want to appear on the buttons' faceplates.
Both buttons (Modify and Delete) will be named "action_button" since that's what we want to index the $_POST array with.  In other words, the 'name' of the buttons along cannot carry any uniquely identifying information if we want to process them systematically after submit. Since these buttons will exist for every user in the list, we need some further way to distinguish them, so that we know for which user one of the buttons has been pressed.
Using arrays is the way to go.  Assuming that we know the unique numerical identifier of each user, such as their primary key from the database, and we DON'T wish to protect that number from the public, we can make the 'action_button' into an array and use the user's unique numerical identifier as a key in this array.
Our HTML code to display the buttons will become:
<input type="submit" value="Delete" name="action_button[0000000002]">
<input type="submit" value="Modify" name="action_button[0000000002]">
The 0000000002 is of course the unique numerical identifier for this particular user.
Then when we handle this form in PHP we need to do the following to extract both the 'value' of the button ("Delete" or "Modify") and the unique numerical identifier of the user we wish to affect (0000000002 in this case). The following will print either "Modify" or "Delete", as well as the unique number of the user:
<?
$submitted_array = array_keys($_POST['action_button']);
echo ($_POST['action_button'][$submitted_array[0]] . " " . $submitted_array[0]);
?>
$submitted_array[0] carries the 0000000002.
When we index that into the $_POST['action_button'], like we did above, we will extract the string that was used as 'value' in the HTML code 'input' tag that created this button.
If we wish to protect the unique numerical identifier, we must use some other uniquely identifying attribute of each user. Possibly that attribute should be encrypted when output into the form for greater security.
Enjoy!

un shift
This function takes a recurring form item from php://input and loads it into an array - useful for javascript/dom incompatibility with form_input_item[] names for checkboxes, multiple selects, etc.  The fread maxes out at 100k on this one.  I guess a more portable option would be pulling in ini_get('post_max_size') and converting it to an integer.
function multi_post_item($input_item_name) {
    $array_output = array();
    $in_handle = fopen("php://input", "r");
    $raw_input_items = split("&", urldecode(fread($in_handle, 100000)));
    foreach ($raw_input_items as $input_item) {
           // split this item into name/value pair
           $item = split("=", $input_item);
           // form item name
           $item_name = $item[0];
           // form item value
           $item_value = $item[1];
           if ($item_name == $input_item_name) {
                   $array_output[] = $item_value;
           }
    }
    return $array_output;
}

darren
This function is a simple solution for getting the array of selectes from a checkbox list or a dropdown list out of the Querry String. I took an example posted earlier and simplified it.
function multi_post_item($repeatedString) {
// Gets the specified array of multiple selects and/or
// checkboxes from the Query String
$ArrayOfItems = array();
$raw_input_items = split("&", $_SERVER["QUERY_STRING"]);
foreach ($raw_input_items as $input_item) {
$itemPair = split("=", $input_item);
if ($itemPair[0] == $repeatedString) {
$ArrayOfItems[] = $itemPair[1];
}
}
return $ArrayOfItems;
}
Use the name of the field as the agrument. Example:
$Order = $_GET['Order'];
$Name = $_GET['Name'];
$States = multi_post_item('States');
$Products = multi_post_item('Products');
Be sure to check for NULL if there are no selections or boxes checked.

tim
This code module can be added to every form using require_once().
It will process any and all form data, prepending each variable with
a unique identifier (so you know which method was used to get the data).
My coding could be neater, but this sure makes processing forms much easier!
<?php
// -----------------------------------------------------------------
// Basic Data PHP module. This module captures all GET, POST
// and COOKIE data and processes it into variables.
// Coded April, 2005 by Timothy J. Pauly
// www.timpauly.com
// -----------------------------------------------------------------
//
// coo_ is prepended to each cookie variable
// get_ is prepended to each GET variable
// pos_ is prepended to each POST variable
// ses_ is prepended to each SESSION variable
// ser_ is prepended to each SERVER variable
session_start(); // initialize session data
$ArrayList = array("_POST", "_GET", "_SESSION", "_COOKIE", "_SERVER"); // create an array of the autoglobal arrays
// we want to process
foreach($ArrayList as $gblArray) // process each array in the array list
{
  $prefx = strtolower(substr($gblArray,1,3))."_"; // derive the prepend string
// from the autoglobal type name
  $tmpArray = $$gblArray;
  $keys = array_keys($tmpArray); // extract the keys from the array being processed
  foreach($keys as $key) // process each key
   {
     
   $arcnt = count($tmpArray[$key]);
   
   if ($arcnt > 1) // Break down passed arrays and
// process each element seperately
   {
     $lcount = 0;
     foreach ($tmpArray[$key] as $dval)
       {
          $prkey = $prefx.$key; // create a new key string
// with the prepend string added
          $prdata['$prkey'] = $dval; // this step could be eliminated
          ${$prkey}[$lcount] = $prdata['$prkey']; //create new key and insert the data
          $lcount++;
       }
     
       } else { // process passed single variables
       
               $prkey = $prefx.$key; // create a new key string
// with the prepend string added
               $prdata['$prkey'] = $tmpArray[$key]; // insert the data from
// the old array into the new one
               $$prkey = $prdata['$prkey']; // create the newly named
// (prepended) key pair using variable variables :-)
             
               
              }
   }
}
// -------------------------------------------------------------
?>

epr3
there is more simple to generate the checkbox and recognize
which box is clicked
<?php
echo '<script language="JavaScript" type="text/JavaScript">
var t = 0;
</script>';
for($i = 0 ;$i <5 ;$i++){

 echo '
 <script language="JavaScript" type="text/JavaScript">
 
 t++;
 
 document.writeln(t);
 document.writeln("<input type=\"checkbox\" name=\"cbx_foo[]\" value=\"" + t + "\">");
 
 </script>
 ';
}
foreach($_POST['cbx_foo'] as $value) {
   echo "
You clicked checkbox number " . $value . "\n";
}
?>

soeren
The decision in PHP to translate a query string like:
a=2&a=3&a=4
into one single variable a=4 is simply strupid!
The "wonderful" hack allowing multiple values to be read only if one uses:
a[]=2&a[]=3&a[]=4
is - at first sight - a nice feature but soon become a pain in the a..!
In ASP and ASPX the first situation is handled as:
a=2,3,4
which is better than the PHP behaviour but still bad (what if your variable values contain commas?).
It seems to me that the proper behaviour would be:
a=2&a=3&a=4
automatically generates an array with all the variables inside. I know this would require proper error handling but evevy things does anyway!

mordae
Small note to previous post; $this can not be redeclared in PHP 5.

ch1902uk
Regarding image input buttons, above where it says:
"When the user clicks somewhere on the image, the accompanying form will be transmitted to the server with two *additional* variables, sub_x and sub_y. These contain the coordinates of the user click within the image."
This is the case with Firefox (and probably other standards browsers), however my experience with Internet Explorer is that when image inputs are clicked, they only submit the location of the click on the button and *not* the name of the input.
So if you have a form to move/delete entries like this
entry[]  [delete_0] [up_0] [down_0]
entry[]   [delete_1] [up_1] [down_1]
entry[]   [delete_2] [up_2] [down_2]
Then submitting the form in firefox will give you post variables such as
<?php
  $_POST['delete_2'];   // "Delete" - button value
  $_POST['delete_2_x'];   // 23 - x coord
  $_POST['delete_2_y'];   // 3 - y coord
?>
In IE you only get
<?php
  $_POST['delete_2_x'];   // 23 - x coord
  $_POST['delete_2_y'];   // 3 - y coord
?>
So if you are checking for what button was clicked do something like this
<?php
  for ($i = 0; $i < count($_POST['entry']); $i++)
  {
     if (isset($_POST['delete_' . $i . '_x']))
     {
        // do delete
     }
  }
?>

user: "someuser"
Numerous string like:
if (isset($_POST["var1"]))
   $var1=$_POST["var1"];
else $var1='';
...
if (isset($_POST["varN"]))
   $varN=$_POST["varN"];
else $varN='';
Can be replaced with:
get_superglobal_vars_from_POST('var1',...,'varN');
function get_superglobal_vars_from_POST()
{
   $numargs = func_num_args();
   $setargs = 0; // for counting set variables
   for ($i=0; $i<$numargs; $i++)
   {
$varname=func_get_arg($i);
if (!isset($_POST[$varname]))
   $result='';
else
{
   $result=$_POST[$varname];
   $setargs++;
}
$GLOBALS["$varname"]=$result;
   }
   return $setargs; // who cares?
}

jesper
Just to help others with the same stupid problem i have:
I you use a checkbox in your form, it will only return the value specified in value if it is checked.
ex. <input type="checkbox" value="yes">
in php code you then write
$checkboxchecked = ($checkbox == "yes");
I guess :)

hyan christian
Just to complete Murat TASARSU's post in this page.
I hope this will help anyone who is going to add it with fsockopen
<html>
 <body>
   <form method="post" action="">
     <input name="fruit" value="banana" /><br />
     <input name="color" value="yellow" /><br />
     <input type="submit" value="Click It">
   </form>
   <br />
   <b>POST</b> :
<?php
$be_var = $_POST;
foreach ( $be_var as $key => $value ) {
$be_var = $be_var."&".$key."=".$value;
}
echo str_replace( "Array&", "", $be_var ); // fruit=banana&color=yellow
?>
 </body>
</html>

jan.gacioch
Just a correction regarding 'cscotti@ifrance' contribution: code '$first = $item_value;' should be place just BEFORE the 'else if' condition and NOT AFTER.
So correct code would be:
function multi_post_item() {
$array_output = array();
$raw_input_items = split("&", $_SERVER["QUERY_STRING"]);
foreach ($raw_input_items as $input_item) {
// split this item into name/value pair
$item = split("=", $input_item);
// form item name
$item_name = urldecode($item[0]);
// form item value
$item_value = urldecode($item[1]);
if ( !isset($array_output[$item_name]) ) {
$array_output[$item_name] = $item_value;
$first = $item_value;
} elseif ( !is_array($array_output[$item_name]) ) {
$array_output[$item_name] = array();
$array_output[$item_name][]= $first;
$array_output[$item_name][]= $item_value;
} else {
$array_output[$item_name][]= $item_value;
}
}
return $array_output;
}

07-nov-2003 05:07
It's been driving me mad, but I've finally worked out the only way to reliably allow form data to be fed back into a form (for editing a record, for instance) is like this:
echo "<input type='text' name='varname' ";
if(isset($existingvalue))
  echo "value=\"".htmlspecialchars(stripslashes($existingvalue))."\" ";
echo "/>";
This assumes that variables have been escaped (such as addslashes) after being retrieved from the database or after being received from a (probably this) form.
Note the type of quotes used in the code above: the value attribute must use escaped double-quotes, and the echo command must use double-quotes, or errors occur when single quotes appear in the data. htmlspecialchars will protect the form from errors caused by data that contains double quote marks, and it stops errors occurring when triangle brackets < > are present in the data.
Alas, to make your site display properly, you must also use htmlspecialchars every time string data is displayed to the user.
There might be an easier way of allowing data to safely be put back into a form, but if there is, I've spent a lot of time not finding it.

cscotti@ifrance
In reply to the second post:
This function construct an HTTP vars array
It is useful for javascript/dom incompatibility with form_input_item[] names for checkboxes, multiple selects, etc.
function multi_post_item() {
   $array_output = array();
   $raw_input_items = split("&", $_SERVER["QUERY_STRING"]);
   foreach ($raw_input_items as $input_item) {
          // split this item into name/value pair
          $item = split("=", $input_item);
          // form item name
          $item_name = urldecode($item[0]);
          // form item value
          $item_value = urldecode($item[1]);
          if (!isset($array_output[$item_name]) ) {
               $array_output[$item_name] = $item_value;  
          }else if (!is_array($array_output[$item_name])){
          $first = $item_value;
          $array_output[$item_name] = array();
          $array_output[$item_name][]= $first;
          $array_output[$item_name][]= $item_value;
          }else{
          $array_output[$item_name][]= $item_value;
          }
   }
  return $array_output;
}

yasuo_ohgaki
Important:  Pay attention to the following security concerns when handling user submitted  data :
http://www.php.net/manual/en/security.registerglobals.php
http://www.php.net/manual/en/security.variables.php

keli
image type inputs apparently return their "value" argument from Mozilla, but not from IEXplorer... :(
example:
<input type="image" name="sb" value="first" src="first.jpg">
using a mozilla will give you
 $sb="first" AND $sb_x, $sb_y ... whereas from IE there's just no $sb. :(
[this in short form, as I'm still using trackvars :) ]

murat tasarsu
if you want your multiple select returned variable in comma seperated form you can use this. hope that helps. regards...
$myvariable
  Array ( [0] => one [1] => two [2] => three )
turns into
  one,two,three
<?php
$myvariable="";
$myseperator="";
foreach ( $_POST["myvariable"] as $v) {
if (!isset($nofirstcomma)) $nofirstcomma=0; else $myseperator=",";
$myvariable = $myvariable.$myseperator.$v;
}
echo $myvariable;
?>

kevinrlat nospam dot ccs dot neu dot edu
if you use an array of checkboxes to submit info to a database or what have you, be careful of the case when no boxes are checked.  for example:
<form method="post">
<input type="checkbox" name="checkstuff[]" value="0">
<input type="checkbox" name="checkstuff[]" value="1">
<input type="checkbox" name="checkstuff[]" value="2">
. . .
</form>
if these are submitted and none are checked, the $_POST['checkstuff'] variable will not contain an empty array, but a NULL value.  this bothered me when trying to implode() the values of my checkboxes to insert into a database, i got a warning saying the 2nd argument was the wrong type.  
hope this helps!
-kevin

mattij
If you try to refer or pass HTML-form data which has arrays with javascript remember that you should point to that array like this
<script type="text/javascript">
window.opener.document.forms[0]["to[where][we][point]"];
</script>

agup
If you have multiple checkboxes that you want to submit from an html form to process elsewhere, you might try using this methodology:
1) create a unique id number for each row in the table
2) assign that unique row id to each checkbox input name
3) pass the total number of rows as a hidden value in the form
4) recover all the checkbox booleans by iterating through all the unique settings.
5) on the downstream page you can assign any value you want to the variable before writing it to the database or whatever you need to do. For example; you can assign the value 0 if the boolean for the checkbox is FALSE.
row=0;
do{
<form name="some_name" action="some_action.php" method="post">
<td><input type="checkbox" name="unique_item[<?echo$row?>]">
<INPUT TYPE="hidden" name="row_count" value="<?echo$row?>"></INPUT>
<INPUT TYPE="submit" name="....">
.
.
row++;
}
while (something);
</table>
</form>
Upon submit, all the unique checkbox booleans can then be recovered on another PHP page using:
$some_data = $_POST['some_data'];
$row_count = $_POST['row_count'];
$row=0;
do {
if($some_data[$row]){
...do something...e.g. assign a variable, write to db, etc.
}
if(!$some_data[$row]){
...do something...e.g. assign a variable, write to db, etc.
}
$row++;
}
while ($row<$row_count);
I left out alot of syntax since this example is simply illustrative to cover multiple scenarios. Don't forget to always validate form data before entering it into a database. I hope this helps.

mail
If you have form data that could be coming in via either GET or POST and register_globals is off (as it should be) use the empty() function to find out where the data is coming from, as in the following example
if(empty($_GET)) {
$clientfilter = $_POST['clientfilter'];
$branchfilter = $_POST['branchfilter'];
}
if(empty($_POST)) {
$clientfilter = $_GET['clientfilter'];
$branchfilter = $_GET['branchfilter'];
}
Big thank you to all the people posting helpful comments on these boards, I dont know what i'd do without you. <a href="www.paulodeon.com">www.paulodeon.com</a>

nospam
I've combined the method of converting old code suggested by solar at heliacal dot net into the improved script below.  This one works whether the submit is get or post and, as in my previous contribution, sets any unsubmitted variables to null, preventing errors.  This supercedes my previous post below (if it hasn't been deleted yet).
$expected=array(
'name', // Only accept these variables from a submit!
'email',
'favorite_color'
); foreach ($expected as $formvar)
$$formvar = (isset(${"_$_SERVER[REQUEST_METHOD]"}[$formvar]))?
  ${"_$_SERVER[REQUEST_METHOD]"}[$formvar]:NULL;

hjncom
I think '[' and ']' are valid characters for name attributes.
http://www.w3.org/TR/html401/interact/forms.html#h-17.4
-> InputType of 'name' attribute is 'CDATA'(not 'NAME' type)
http://www.w3.org/TR/html401/types.html#h-6.2
-> about CDATA('name' attribute is not 'NAME' type!)
...CDATA is a sequence of characters from the document character set and may include character entities...
http://www.w3.org/TR/html401/sgml/entities.html
--> about Character entity references in HTML 4
([ - &#91, ] - &#93)

imarvintpa
I saw a note from
jan.gacioch at motorola dot com
posted on
19-Feb-2004 11:52
"Just a correction regarding 'cscotti@ifrance' contribution: code '$first = $item_value;' should be place just BEFORE the 'else if' condition and NOT AFTER."
This is not true, if the form has things posted in an unusual order, the $first value will be from a completely different variable.
Also, nobody mentioned this, but in the PHP.ini file there is an option called "always_populate_raw_post_data".  It'll fill in that variable.  It took me a while to find it.
I think it is bad to consider form name fields to be case sensitive, so my version uses all uppercase form values.
I also use a Request function to pull the data out of the global variables so I don't get warnings or errors when I try to access an undefined variable.  I usually just want an empty string for them.  (I have the same for Session and Server.)
UCase is shorter than strtoupper and I have a lot of converted ASP code and it was easier to create alias functions than to replace them.
<?
$_ATBREQUEST = multi_post_item();
function multi_post_item() {
$rawpost = Globals('HTTP_RAW_POST_DATA');
$array_output = array();
$raw_input_items = split("&", addbit3(Server("QUERY_STRING"), $rawpost, "&"));
foreach ($raw_input_items as $input_item) {
// split this item into name/value pair
//Print $input_item . BR;
if ($input_item != "") {
$item = split("=", $input_item);
// form item name
$item_name = ucase(urldecode($item[0]));
// form item value
if (empty($item[1]))
$item_value = "";
else
$item_value = urldecode($item[1]);

if ( !isset($array_output[$item_name]) ) {
$array_output[$item_name] = $item_value;
} elseif ( !is_array($array_output[$item_name]) ) {
$first = $array_output[$item_name];
$array_output[$item_name] = array();
$array_output[$item_name][]= $first;
$array_output[$item_name][]= $item_value;
} else {
$array_output[$item_name][]= $item_value;
}
}
}
return $array_output;
}
function Request2($param){
if (empty($_REQUEST[$param])) {
return "";
}
else
return $_REQUEST[$param];
}
function Request($param){
global $_ATBREQUEST;
$uparam = ucase($param);
if (empty($_ATBREQUEST[$uparam])) {
return Request2($param);
}
else{
if (is_array($_ATBREQUEST[$uparam])){
return implode(", ", $_ATBREQUEST[$uparam]);
}
else
return $_ATBREQUEST[$uparam];
}
}
//We want the array
function RequestArray($param){
global $_ATBREQUEST;
$uparam = ucase($param);
if (empty($_ATBREQUEST[$uparam])) {
return array(Request2($param));
}
else{
return $_ATBREQUEST[$uparam];
}
}
//AddBit 1 and 2 are commas and semicolons respectively.
function AddBit3($mystr, $mynew, $mysep) {
   if ($mystr . "" == "")
$mystr = $mynew;
   else
$mystr .= $mysep . $mynew;
   return $mystr;
}
function Server($param){
if (empty($_SERVER[$param]))
return "";
else
return $_SERVER[$param];
}
function UCase($str){
return strtoupper($str);
}
?>

dreptack
I needed to post html form through image input element. But my problem was I had to use multiple image-buttons, each one for a single row of form table. Pressing the button was mention to tell script to delete this row from table and also (in the same request) save other data from the form table.
I wrote simple test-script to see what variable I should check for in a script:
I have a html document:
<form action="test.php" method="post">
<input type="image" name="varscalar" src="/images/no.gif" />
<input type="image" name="vararray[12]" src="/images/no.gif" />
</form>
And a php script:
<?php
 if ($_POST) {
   echo "post: <pre>"; print_r($_POST); echo '</pre>';
 }
?>
What I've discovered suprised me a lot.
After hitting on varscalar:
post:
Array
(
   [varscalar_x] => 6
   [varscalar_y] => 7
)
After hitting on upper right corner of vararray:
post:
Array
(
   [vararray] => Array
       (
           [12] => 2
       )
)
This mean when clicking on image-type input element, which name is an array, only y-part of a value is remembered.
The result is the same on: php 4.1.2 on Win98se, php 4.3.9-1 on linux

jim
How to pass a numerically indexed array.
This is the part inside the form. Notice that the name is not 'english[$r]' which you would normally write, but 'english[]'. PHP adds the index when it receives the post and it starts at 0.
<?php
for ($r=0; $r <= count($english)-1; $r++){
        echo "<TEXTAREA NAME='english[]'>".$english[$r]."</TEXTAREA>";
     
}
?>
<?php
And this will get it out at the other end
function retrieve_english(){
for ($r=0; $r <= count($_POST['english'])-1; $r++){
echo $_POST['english'][$r]."
";
}
}
?>
Keys are useful but so are numerical indices!
Cheers everyone

__kbanks
Hi all:
I'm presently building a solution to programmatically build, view, and validate HTML forms when I came across the ol' PHP non-scalar form variable handling problem.  Because my form validator class would really have no way of knowing if a given form variable was meant to be scalar or not, I decided to TREAT ALL PHP FORM VARIABLES AS ARRAYS, i.e., to use the '[]' syntax for all variables, scalar or not.  This way, the form designer need not remember to specify the '[]' syntax, and the Form->HTML transformer need not scan for every input within the form, looking for duplicate names.  This also eliminates the risk of losing data you meant to keep in an array but to which you forgot to apply the '[]' syntax.  
You may then either treat all form variables as arrays in your form handling code, or you may, as I intend to do, filter each HTML request through a Front Controller (desc. in Fowler, PoEAA).  The Front Controller would convert all arrays of length 1 to a scalar variable and leave multi-element arrays as they are.  This should essentially convert PHP's handling of non-scalar form variables to that of ASP's (or slightly better, since multiple form values of the same name will actually be arrays, not just comma-seperated values).  
This way my Form Validator class can just check if the input to validate is an array, and then apply some constraint across each element in the array.

jonas lindeløv
Here is my solution to the following annoying problems:
- When POSTing data and updating/going back one page, an annoying message appears from the browser since the POST data has been preserved.
- External user-inputs (POST and GET) are devided into two arrays (POST and GET).
Problems often solved with rather exotic solutions, dependent on the specific context. This is my exotic solution, independent of context. A little code-block to be copy-pasted to the top of the desired PHP document. Performing in about 0.1 ms, session_start() not included + around 0.01 ms pr. input variable.
Filestreams and URL modifications must be executed before this class is executed.
Overview: collects POST and GET data in a class. When data is POSTed, the data is serialized into a session variable, page is reloaded (without POST data) and the data is unserialized into the class again for use through the rest of the document.
<?PHP
session_start();
class _xvar {
function _xvar() {
if(!$_SESSION['xvars_serialized']) {
// If data has just been recieved, it is saved in $this and the current URL is builded.
foreach ($_GET as $key => $value) $this->{$key} = $value;
foreach($_POST as $key => $value) $this->{$key} = $value;
$this->doc_url = 'http://' .$_SERVER['HTTP_HOST'] .$_SERVER['PHP_SELF'] .'?' .$_SERVER['argv'][0];

// If no POST data is recieved, nothing more is to be done. If POST data is recieved it is serialized to session and the page is redirected to itself with GET data but without POST data.
if($_POST) {
$_SESSION['xvars_serialized'] = serialize($this);
header('Location: ' .$this->doc_url);
exit();
}
}
// Just after the above redirecting, GET and POST data is unserialized into the object.
else {
$this = unserialize($_SESSION['xvars_serialized']);
$_SESSION['xvars_serialized'] = 0;
}
}
}
$_XVAR = new _xvar;
// Calling the data throughout the document.
echo $_XVAR->foo;
?>
I find it very useful in my project-management systems with lots of forms and links as user-inputs. The code is completly $_GET and $_POST free! :-)

aescomputer
Here are two usefull functions for forms:
<?php
// clean html tags out of url attributes
   if(!empty($_REQUEST)){
       foreach($_REQUEST as $x => $y){
           $_REQUEST[$x] = str_replace('<', '&lt;', str_replace('>', '&gt;', $y));
       }
   }
// replace carrage returns in url attributes with
if(!empty($_REQUEST)){
       foreach($_REQUEST as $x => $y){
           $_REQUEST[$x] = str_replace("\n", '
', $y);
       }
   }
?>

vb
For what I understand, since PHP 4.3 it is possible to access the content of a POST request (or other methods as well) as an input stream named php://input, example:
readfile("php://input");  
[to display it]
or
$fp = fopen("php://input", "r");    
[to open it and then do whatever you want]
This is very useful to access the content of POST requests which actually have a content (and not just variable-value couples, which appear in $_POST).
This substitutes the old $HTTP_RAW_POST_DATA variable available in some of the previous 4.x versions. It is available for other upload methods different from POST too, but it is not available for POSTs with multipart/form-data content type, since the file upload handler has already taken care of the content in that case.

t.montg
For anyone else having trouble figuring out how to access values in a SELECT element from a POST or GET form, you can't set the "id" attribute to the same thing as your "name" attribute.  i.e. don't do this:
<?php
 //Not so good
 <select multiple="multiple" id="selectElem" name="selectElem[]">
    <option value="ham">Ham</option>
    <option value="cheese">Cheese</option>
    <option value="hamcheese">Ham and Cheese</option>
 </select>
?>
If you do the above, the variable $_POST['selectElem'] will not be set.  Instead, either change the id or name attribute so that they are dissimilar.  i.e. do this:
<?php
 //So good (notice the new "id" value)
 <select multiple="multiple" id="selectElemId" name="selectElem[]">
    <option value="ham">Ham</option>
    <option value="cheese">Cheese</option>
    <option value="hamcheese">Ham and Cheese</option>
 </select>
?>
Then you can access the value(s) of the SELECT element through the array $_POST['selectElem'][] or $_GET['selectElem'][].  It took me quite some time to figure out the problem.

pascal dot poncet
Concerning the use of both javascript and php in working with forms :
In a php code, it's quiet easy and practical to use names like "fieldname[]" in checkbox input type html elements. You will then retrieve the value(s) transmitted in the "fieldname" array type variable.
But a difficulty appears in coding some javascript function able to manipulate those fields values to verify them, as "fieldname[]" must not be recognize directly as an array in the script.
Here is a nice way to solve this question :
(html code)
 <form method="post" action="..." onsubmit="return verifyForm(this)">
   <input type="checkbox" name="colors[]" value="black"> black
<input type="checkbox" name="colors[]" value="white"> white
<input type="checkbox" name="colors[]" value="other"> other color
</form>
(javascript code)
 function verifyForm(form) {
   var selColors=new String();
   for(i=0;i<form["colors[]"].length;i++)
     if(form["colors[]"][i].checked) selColors+=form["colors[]"][i].value;
   if(selColors=="") msgErr="You have to check at least one choice of color";
   ...
 }
Of course, you may also verify anything else about the checked values, like the value itself, only by using 'form["colors[]"][i].value' instead of '...checked'.
Happy to help you,
Pascal
PS : apologying for my bad english.

a
As far as whether or not "[]" in name attributes goes, The HTML4.01 specification only requires that it be a case-insensitive CDATA token, which can quite happily include "[]". Leading and trailing whitespace may be trimmed and shouldn't be used.
It is the id= attribute which is restricted, to a case-sensitive NAME token (not to be confused with a name= attribute).

任侠 hsh_crack
a simple example:
<?
if(!isset($_POST["username"]))
{
?>
<form action=<? echo $_SERVER['PHP_SELF'] ?> method="post">
&#22995;&#21517;:<input type="text" name="username">
&#30005;&#23376;&#37038;&#20214;:<input type="text" name="email">
<input type="submit" name="submit" value="&#25552;&#20132;">
</form>
<?
}
else{echo $_POST["username"];} ?>

carl_steinhilber
A group of identically-named checkbox form elements returning an array is a pretty standard feature of HTML forms. It would seem that, if the only way to get it to work is a non-HTML-standard-compliant workaround, it's a problem with PHP.
Since the array is passed in the header in a post, or the URL in a get, it's the PHP interpretation of those values that's failing.

mraymer
A further thought about the checkbox without check mentioned above.  Rather than writing in a HIDDEN element.  Why not have your validation code check for the variable of the checkbox like so:
Assume HTML form has the following unchecked checkbox:
<INPUT TYPE='CHECKBOX' NAME="CATEGORY[]">Category Name</INPUT>
then your ACTION script in the form points to a script which has:
if (!isset($checkbox))
 {
 CATEGORY[] = "off";
 }
If you were dynamically creating the checkboxs, then, most likely, you would have your hands on the keys for each CATEGORY and you could create something like:
while (list($cat_id,$cat_title) = each($categories))
 {
   if (isset($category))
     {
if (!$category[$cat_id])
 {
   $category[$cat_id] = "off";
 }
else
 {
   $category[$cat_id] = "on";
 }
     }
   else
     {
$category[$cat_id] = "off";
     }
 }
Assuming that you have an array named $categories constructed with unique keys and category titles.

04-mar-2003 03:21
"...the dot (period, full stop) is not a valid character in a PHP variable name."
That's not completely correct, consider this example:
$GLOBALS['foo.bar'] = 'baz';
echo ${'foo.bar'};
This will output baz as expected.

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