The best practice for checking variable - php

Which one is the best practice to use the argument values?
Below is the php code I wrote inside a Wordpress theme.
function kpn_page_banner($args) {
if (!$args['title']) {
$args['title'] = the_title();
}
!$args['title'] && $args['title'] = the_title();
$title = $args['title'] ? $args['title'] : the_title();
// ...
}

Is not recommended to access array keys without checking its existence. If you do in that way you can get some Notices.
if(!isset($args['title']) || ( isset($args['title']) && trim($args['title']) === '')) {
$args['title'] = the_title();
}
Also, don't ever try to reduce the size of an if statement by excluding some conditions that are so important, like isset is in your case.
Check out more http://php.net/manual/ro/function.isset.php

Related

Php mail() echo showing all the time [duplicate]

I'm trying to check whether a $_POST exists and if it does, print it inside another string, if not, don't print at all.
something like this:
$fromPerson = '+from%3A'.$_POST['fromPerson'];
function fromPerson() {
if !($_POST['fromPerson']) {
print ''
} else {
print $fromPerson
};
}
$newString = fromPerson();
Any help would be great!
if( isset($_POST['fromPerson']) )
{
$fromPerson = '+from%3A'.$_POST['fromPerson'];
echo $fromPerson;
}
Simple. You've two choices:
1. Check if there's ANY post data at all
//Note: This resolves as true even if all $_POST values are empty strings
if (!empty($_POST))
{
// handle post data
$fromPerson = '+from%3A'.$_POST['fromPerson'];
echo $fromPerson;
}
(OR)
2. Only check if a PARTICULAR Key is available in post data
if (isset($_POST['fromPerson']) )
{
$fromPerson = '+from%3A'.$_POST['fromPerson'];
echo $fromPerson;
}
Surprised it has not been mentioned
if($_SERVER['REQUEST_METHOD'] == 'POST' && isset($_POST['fromPerson'])){
Everyone is saying to use isset() - which will probably work for you.
However, it's important that you understand the difference between
$_POST['x'] = NULL; and $_POST['x'] = '';
isset($_POST['x']) will return false on the first example, but will return true on the second one even though if you tried to print either one, both would return a blank value.
If your $_POST is coming from a user-inputted field/form and is left blank, I BELIEVE (I am not 100% certain on this though) that the value will be "" but NOT NULL.
Even if that assumption is incorrect (someone please correct me if I'm wrong!) the above is still good to know for future use.
isset($_POST['fromPerson'])
The proper way of checking if array key exists is function array_key_exists()
The difference is that when you have $_POST['variable'] = null it means that key exists and was send but value was null
The other option is isset() which which will check if array key exists and if it was set
The last option is to use empty() which will check if array key exists if is set and if value is not considered empty.
Examples:
$arr = [
'a' => null,
'b' => '',
'c' => 1
];
array_key_exists('a', $arr); // true
isset($arr['a']); // false
empty($arr['a']); // true
array_key_exists('b', $arr); // true
isset($arr['b']); // true
empty($arr['b']); // true
array_key_exists('c', $arr); // true
isset($arr['c']); // true
empty($arr['c']); // false
Regarding your question
The proper way to check if value was send is to use array_key_exists() with check of request method
if ($_SERVER['REQUEST_METHOD'] == 'POST' && array_key_exists('fromPerson', $_POST)
{
// logic
}
But there are some cases depends on your logic where isset() and empty() can be good as well.
In that case using method isset is not appropriate.
According to PHP documentation: http://php.net/manual/en/function.array-key-exists.php
(see Example #2 array_key_exists() vs isset())
The method array_key_exists is intended for checking key presence in array.
So code in the question could be changed as follow:
function fromPerson() {
if (array_key_exists('fromPerson', $_POST) == FALSE) {
return '';
} else {
return '+from%3A'.$_POST['fromPerson'];
};
}
$newString = fromPerson();
Checking presence of array $_POST is not necessary because it is PHP environment global variable since version 4.1.0 (nowadays we does not meet older versions of PHP).
All the methods are actually discouraged, it's a warning in Netbeans 7.4 and it surely is a good practice not to access superglobal variables directly, use a filter instead
$fromPerson = filter_input(INPUT_POST, 'fromPerson', FILTER_DEFAULT);
if($fromPerson === NULL) { /*$fromPerson is not present*/ }
else{ /*present*/ }
var_dump($fromPerson);exit(0);
Try
if (isset($_POST['fromPerson']) && $_POST['fromPerson'] != "") {
echo "Cool";
}
I would like to add my answer even though this thread is years old and it ranked high in Google for me.
My best method is to try:
if(sizeof($_POST) !== 0){
// Code...
}
As $_POST is an array, if the script loads and no data is present in the $_POST variable it will have an array length of 0. This can be used in an IF statement.
You may also be wondering if this throws an "undefined index" error seeing as though we're checking if $_POST is set... In fact $_POST always exists, the "undefined index" error will only appear if you try to search for a $_POST array value that doesn't exist.
$_POST always exists in itself being either empty or has array values.
$_POST['value'] may not exist, thus throwing an "undefined index" error.
Try isset($_POST['fromPerson'])?
if (is_array($_POST) && array_key_exists('fromPerson', $_POST)) {
echo 'blah' . $_POST['fromPerson'];
}
if( isset($_POST['fromPerson']) ) is right.
You can use a function and return, better then directing echo.
I like to check if it isset and if it's empty in a ternary operator.
// POST variable check
$userID = (isset( $_POST['userID'] ) && !empty( $_POST['userID'] )) ? $_POST['userID'] : null;
$line = (isset( $_POST['line'] ) && !empty( $_POST['line'] )) ? $_POST['line'] : null;
$message = (isset( $_POST['message'] ) && !empty( $_POST['message'] )) ? $_POST['message'] : null;
$source = (isset( $_POST['source'] ) && !empty( $_POST['source'] )) ? $_POST['source'] : null;
$version = (isset( $_POST['version'] ) && !empty( $_POST['version'] )) ? $_POST['version'] : null;
$release = (isset( $_POST['release'] ) && !empty( $_POST['release'] )) ? $_POST['release'] : null;
I recently came up with this:
class ParameterFetcher
{
public function fetchDate(string $pDate):string{
$myVar = "";
try{
if(strlen($_POST[$pDate]) > 0){
$myVar = $_POST[$pDate];
}
}catch (Exception $faild){
die("field NULL or not set for $pDate");
}
[ ... other stuff ]
to fetch a date obviously, but it can take ANY post param. You can also check for GET this way.

Get value in URL PHP

When I submit a form with wrong id's, the url is set like this :
url-test.com/connexion/?login-failed
I want to trigger login-failed to make conditions.
Here's my code, but it does not work
$login_failed = $_GET['login-failed'];
if($login_failed) {
$error = 'Oups failed';
}
//My form
<?php wp_login_form(); ?>
<p><?php if(isset($error)) {echo $error;} ?></p>
Thanks for your help !
if(isset($login_failed)) {
$error = 'Oups failed';
}
You have to check that it's isset.
Your code isn't working, because you're store the value of $_GET['login-failed], but actually there's no value. If you change ?login-failed to ?login-failed=1, it should works.
Otherwise, you should check if variable isset, e.g:
$login_failed = isset( $_GET['login-failed'] ) ? true : false;

How to add another page ID in a PHP function - newbie asking?

I need some help to see where I am going wrong.
I am trying to add a page ID to this original function:
<?php if( $post->ID != '91' )
{
get_sidebar();
} ?>
>
to also exclude the ID 1267.
I am trying this, with no success.
<?php
$pageIDs_to_exclude=array("91","1267");
if( $post->ID != $pageIDs_to_exclude )
{
get_sidebar();
}
?>
Surely there must be a better way of doing this? Or what am I missing?
Thnaks for any help
/Anders
$pageIDs_to_exclude = array("91","1267");
// in_array will return false if it doesn't find $post->ID within the $pageIDs_to_exclude array
if( ! in_array($post->ID, $pageIDS_to_exclude) )
{
get_sidebar();
}
You are trying to directly compare $post->ID to $pageIDs_to_exclude, an array. As $post->ID is not an array (it is a string), this is not possible. Instead, see if $post->ID is in $pageIDs_to_exclude.
if (!in_array($post->ID, $pageIDs_to_exclude)) {
get_sidebar();
}
in_array() is a function that will return true if the object is found in the array.
You can use in_array of php. It will return true or false.
$pageIDs_to_exclude=array("91","1267");
if(!in_array($post->ID,$pageIDs_to_exclude))
{
get_sidebar();
}
Use the PHP function in_array() (http://php.net/manual/en/function.in-array.php) to search for a value in an array:
<?php
$page_ids = array("91", "1271");
if(!in_array($post->ID, $page_ids))
{
get_sidebar();
}
?>

isset variables created using extract function

$array = explode('/', $_SERVER['REQUEST_URI']);
$count = count($array);
extract($array, EXTR_PREFIX_ALL, 'var');
can the variables (created using extract function) be isseted automatically? to avoid "Notice: Undefined variable:" errors when error_reporting(E_ALL); is enabled.
thank you
I tried doing something of this sort, still needed to isset() whenever, the variables are used next in the code (when error_reporting(E_ALL); is enabled).
if(isset($var_0))
{
$var_0 = filter_var($var_0, FILTER_SANITIZE_STRING);
}
if(isset($var_1))
{
$var_1 = filter_var($var_1, FILTER_SANITIZE_STRING);
}
if(isset($var_2))
{
$var_2 = filter_var($var_2, FILTER_SANITIZE_STRING);
}
if(isset($var_3))
{
$var_3 = filter_var($var_3, FILTER_SANITIZE_STRING);
}
==========================
Alternatively, tried the one line if condition,
$var_0 = isset($var_0) ? filter_var($var_0, FILTER_SANITIZE_STRING) : '';
$var_1 = isset($var_1) ? filter_var($var_1, FILTER_SANITIZE_STRING) : '';
$var_2 = isset($var_2) ? filter_var($var_2, FILTER_SANITIZE_STRING) : '';
$var_3 = isset($var_3) ? filter_var($var_3, FILTER_SANITIZE_STRING) : '';
while the error got subsided, but, a new problem arises i.e., variables (which are not created by extract function are getting isseted because of this one line if condition approach).
I am posting two of the routing rules (of two urls) in the website.
$pagename = "not-found.php";
//Different Routing Engine Rules follows
if ((isset($var_1)) && (($var_1 == "") || ($var_1 == "index.php"))) {
if((isset($var_2)) || (isset($var_3)) || (isset($var_4)) || (isset($var_5)) || (isset($var_6)) || (isset($var_7)))
{
$pagename = "not-found.php";
}
else
{
$pagename = "default-home.php";
}
}
if (($var_1 == "login"))
{
//echo "Login Page URL\n";
if((isset($var_2)) || (isset($var_3)) || (isset($var_4)) || (isset($var_5)) || (isset($var_6)) || (isset($var_7)))
{
$pagename = "not-found.php";
}
else
{
$pagename = "login.php";
}
}
include "code/" . $pagename;
any help will be appreciated, thank you
If I understand your question correctly then, no. It's still your responsibility to know what variables are available and act accordingly. You can simply disable these notices via error_reporting(E_ALL & ~E_NOTICE) for the portion of code in question.
Edit
Looking at your updated question, I think it would be helpful if you could explain what you're trying to achieve. Personally, I see the use of extract as a bit of a code smell and there may be a better way :)

Check if $_POST exists

I'm trying to check whether a $_POST exists and if it does, print it inside another string, if not, don't print at all.
something like this:
$fromPerson = '+from%3A'.$_POST['fromPerson'];
function fromPerson() {
if !($_POST['fromPerson']) {
print ''
} else {
print $fromPerson
};
}
$newString = fromPerson();
Any help would be great!
if( isset($_POST['fromPerson']) )
{
$fromPerson = '+from%3A'.$_POST['fromPerson'];
echo $fromPerson;
}
Simple. You've two choices:
1. Check if there's ANY post data at all
//Note: This resolves as true even if all $_POST values are empty strings
if (!empty($_POST))
{
// handle post data
$fromPerson = '+from%3A'.$_POST['fromPerson'];
echo $fromPerson;
}
(OR)
2. Only check if a PARTICULAR Key is available in post data
if (isset($_POST['fromPerson']) )
{
$fromPerson = '+from%3A'.$_POST['fromPerson'];
echo $fromPerson;
}
Surprised it has not been mentioned
if($_SERVER['REQUEST_METHOD'] == 'POST' && isset($_POST['fromPerson'])){
Everyone is saying to use isset() - which will probably work for you.
However, it's important that you understand the difference between
$_POST['x'] = NULL; and $_POST['x'] = '';
isset($_POST['x']) will return false on the first example, but will return true on the second one even though if you tried to print either one, both would return a blank value.
If your $_POST is coming from a user-inputted field/form and is left blank, I BELIEVE (I am not 100% certain on this though) that the value will be "" but NOT NULL.
Even if that assumption is incorrect (someone please correct me if I'm wrong!) the above is still good to know for future use.
isset($_POST['fromPerson'])
The proper way of checking if array key exists is function array_key_exists()
The difference is that when you have $_POST['variable'] = null it means that key exists and was send but value was null
The other option is isset() which which will check if array key exists and if it was set
The last option is to use empty() which will check if array key exists if is set and if value is not considered empty.
Examples:
$arr = [
'a' => null,
'b' => '',
'c' => 1
];
array_key_exists('a', $arr); // true
isset($arr['a']); // false
empty($arr['a']); // true
array_key_exists('b', $arr); // true
isset($arr['b']); // true
empty($arr['b']); // true
array_key_exists('c', $arr); // true
isset($arr['c']); // true
empty($arr['c']); // false
Regarding your question
The proper way to check if value was send is to use array_key_exists() with check of request method
if ($_SERVER['REQUEST_METHOD'] == 'POST' && array_key_exists('fromPerson', $_POST)
{
// logic
}
But there are some cases depends on your logic where isset() and empty() can be good as well.
In that case using method isset is not appropriate.
According to PHP documentation: http://php.net/manual/en/function.array-key-exists.php
(see Example #2 array_key_exists() vs isset())
The method array_key_exists is intended for checking key presence in array.
So code in the question could be changed as follow:
function fromPerson() {
if (array_key_exists('fromPerson', $_POST) == FALSE) {
return '';
} else {
return '+from%3A'.$_POST['fromPerson'];
};
}
$newString = fromPerson();
Checking presence of array $_POST is not necessary because it is PHP environment global variable since version 4.1.0 (nowadays we does not meet older versions of PHP).
All the methods are actually discouraged, it's a warning in Netbeans 7.4 and it surely is a good practice not to access superglobal variables directly, use a filter instead
$fromPerson = filter_input(INPUT_POST, 'fromPerson', FILTER_DEFAULT);
if($fromPerson === NULL) { /*$fromPerson is not present*/ }
else{ /*present*/ }
var_dump($fromPerson);exit(0);
Try
if (isset($_POST['fromPerson']) && $_POST['fromPerson'] != "") {
echo "Cool";
}
I would like to add my answer even though this thread is years old and it ranked high in Google for me.
My best method is to try:
if(sizeof($_POST) !== 0){
// Code...
}
As $_POST is an array, if the script loads and no data is present in the $_POST variable it will have an array length of 0. This can be used in an IF statement.
You may also be wondering if this throws an "undefined index" error seeing as though we're checking if $_POST is set... In fact $_POST always exists, the "undefined index" error will only appear if you try to search for a $_POST array value that doesn't exist.
$_POST always exists in itself being either empty or has array values.
$_POST['value'] may not exist, thus throwing an "undefined index" error.
Try isset($_POST['fromPerson'])?
if (is_array($_POST) && array_key_exists('fromPerson', $_POST)) {
echo 'blah' . $_POST['fromPerson'];
}
if( isset($_POST['fromPerson']) ) is right.
You can use a function and return, better then directing echo.
I like to check if it isset and if it's empty in a ternary operator.
// POST variable check
$userID = (isset( $_POST['userID'] ) && !empty( $_POST['userID'] )) ? $_POST['userID'] : null;
$line = (isset( $_POST['line'] ) && !empty( $_POST['line'] )) ? $_POST['line'] : null;
$message = (isset( $_POST['message'] ) && !empty( $_POST['message'] )) ? $_POST['message'] : null;
$source = (isset( $_POST['source'] ) && !empty( $_POST['source'] )) ? $_POST['source'] : null;
$version = (isset( $_POST['version'] ) && !empty( $_POST['version'] )) ? $_POST['version'] : null;
$release = (isset( $_POST['release'] ) && !empty( $_POST['release'] )) ? $_POST['release'] : null;
I recently came up with this:
class ParameterFetcher
{
public function fetchDate(string $pDate):string{
$myVar = "";
try{
if(strlen($_POST[$pDate]) > 0){
$myVar = $_POST[$pDate];
}
}catch (Exception $faild){
die("field NULL or not set for $pDate");
}
[ ... other stuff ]
to fetch a date obviously, but it can take ANY post param. You can also check for GET this way.

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