isset or !empty to determine if Wordpress array has content? - php

I'm using the ACF Gallery plugin for Wordpress that produces an array of image data.
It's called as so:
$floorplans = get_field('floorplans');
My problem is that sometimes, the array doesn't have any proper content e.g if i var_dump() it and they haven't uploaded any content, I get:
string(0) ""
If the result stored in $floorplans is empty, I want the script to skip over some statements.
I've tried:
if(!empty(get_field('floorplans'))){
...
}
... and yet the statements in my if still occur.
I tried:
if(isset(get_field('floorplans'))){
...
}
And I get:
Fatal error: Cannot use isset() on the result of a function call
So then I tried:
$floorplanCount = count(get_field('floorplans'));
if ($floorplanCount !== 0){
...
}
And you guessed it, the statements in the if still pass.
So how can I not run a section of code if there is nothing in my floorplans field?

As mentioned in comments get_field is the culprit, and a shining example of why a function shouldn't return multiple data types (array or string, array or int, etc), because it forces complexity on the calling code to have to figure out what was returned.
Try this:
if (((true === is_array($floorplans)) && (count($floorplans) > 0)) || (false === empty($floorplans))) {
// Do work
}

According to acf gallery documentation, you can use
if($floorplans)
{
//your statements goes here
}
Here is the link. http://www.advancedcustomfields.com/resources/gallery/
The reason why you cant use isset is, the get_field function returns the array if anything exists, else it will return a false or 0 ( Im not sure, but even if it is 0 or false the $floorplan variable should work seamlessly in the if statement as I mentioned above )
Here is more documentation just in case : http://www.advancedcustomfields.com/resources/get_field/

Related

PHP won't display "0" value string?

I'm using Wordpress with Genesis Framework, and I'm having trouble getting values of custom fields to display if they're "0". The values come from a form, and the 0 values are indeed in the post meta in my database. If I change them to anything else, they display perfectly on the single-posttype.php template. However, if they are set to 0, then nothing is displayed. I've included an example of the code I'm using, and yes, I'm aware of my dirty short codes, but it's ok. I know my place. Help?
$customField = genesis_get_custom_field('customField');
add_action('hookLocation','myDirtyShortcodes');
function myDirtyShortcodes(){
echo do_shortcode('[some dirtyshortcodehere'.$customField.' more dirty shortcode]');
}
So as #Machevity mentioned try this way:
add_action('hookLocation','myDirtyShortcodes');
function myDirtyShortcodes(){
$customField = genesis_get_custom_field('customField');
echo do_shortcode('[some dirtyshortcodehere'.$customField.' more dirty shortcode]');
}
Fixed. the genesis_get_custom_field function used a poor method of checking the variable for a null value.
Inside of genesis_get_custom_field,
if ( ! $custom_field )
return '';
Was replaced with
if($custom_field === '')
return '';
In the original function, "0" was returning false. But this quick change (thanks to /u/gu3st12 on Reddit).

PHP isset not working properly on form, with loops and arrays

This is honestly the most finicky and inept language I've ever coded in. I'll be glad when this project is good and over with.
In any case I have to us PHP so here's my question.
I have an Array named $form_data as such:
$form_data = array
('trav_emer_med_insur',
'trav_emer_single',
'trav_emer_single_date_go',
'trav_emer_single_date_ba',
'trav_emer_annual',
'trav_emer_annual_date_go',
'trav_emer_extend',
'trav_emer_extend_date_go',
'trav_emer_extend_date_ef',
'trav_emer_extend_date_ba',
'allinc_insur',
'allinc_insur_opt1',
'allinc_single_date_go',
'allinc_single_date_ba',
'allinc_insur_opt2',
'allinc_annual_date_go',
'allinc_annual_date_ba',
'cancel_insur',
'allinc_annual_date_go',
'allinc_annual_date_ba',
'visitor_insur',
'country_select',
'visitor_supervisa',
'visitor_supervisa_date_go',
'visitor_supervisa_date_ba',
'visitor_student',
'visitor_student_date_go',
'visitor_student_date_ba',
'visitor_xpat',
'visitor_xpat_date_go',
'visitor_xpat_date_ba',
'txtApp1Name',
'txtApp2Name',
'txtApp1DOB',
'txtApp2DOB',
'txtApp1Add',
'txtApp1City',
'selprov',
'txtApp1Postal',
'txtApp1Phone',
'txtApp1Ext',
'txtApp1Email',
'conpref', );
These are the names of name="" fields on an HTML form. I have verified that ALL names exist and have a default value of '' using var_dump($_POST).
What I want to do is very simple, using the $form_data as reference do this:
create a new array called $out_data which can handle the data to display on a regurgitated form.
The structure of $out_data is simple the key will be the name of the element from the other array $out_data[txtApp1Name] for example, and then the value of that key will be the value.
Now what I want is to first check to see if every name="" is set or not, to eliminate errors and verify the data. Then regardless of whether it is set or not, create its placeholder in the $out_data array.
So if $_POST[$form_data[1]] (name is 'trav_emer_single') is not set create an entry in $out_data that looks like this $out_data([trav_emer_single] => "NO DATA")
If $_POST[$form_data[1]] (name is 'trav_emer_single') is set create and entry in $out_data that looks like this: $out_data([trav_emer_single] => "whatever the user typed in")
I have tried this code:
$out_data = array();
$count = count($form_data);
for( $i = 0; $i < $count; $i++ )
{
if(!isset($_POST[$form_data[$i]])) {
$out_data[$form_data[$i]] = "NO_DATA";
}
else {
$out_data[$form_data[$i]] = $_POST[$form_data[$i]];
}
}
Now this code technically is working, it is going through the array and assigning values, but it is not doing so properly.
I have hit submit on the form with NOTHING entered. Therefore every item should say "NO_DATA" on my regurgitated output (for user review), however only some items are saying it. All items I have confirmed have name="" and match the array, and have nothing entered in them. Why is "NO_DATA" not being assigned to every item in the array?
Also of note, if I fill in the form completely $out_data is fully and correctly populated. What is the problem with !isset? I've tried doing $_POST[$form_data[$i]] == '' which does put no_data in every instance of no data, however it throws an 'undefined index' warning for every single item on the page whether I write something in the box or not.
Really I just want to know WTF is going on, the dead line for this project is closing fast and EVERY step of the PHP gives me grief.
As far as I can tell by reading around my code is valid, but refuses to execute as advertised.
If you need more code samples please ask.
Really befuddled here, nothing works without an error, help please.
Thanks
-Sean
Instead of checking !isset(), use empty(). If the form posts an empty string, it will still show up in the $_POST as an empty string, and isset() would return TRUE.
I've replaced your incremental for loop with a foreach loop, which is almost always used in PHP for iterating an array.
$out_data = array();
foreach ($form_data as $key) {
if(empty($_POST[$key])) {
$out_data[$key] = "NO_DATA";
}
else {
$out_data[$key] = $_POST[$key];
}
}
PHP's isset returns TRUE unless the variable is undefined or it is NULL. The empty string "" does not cause it to return FALSE. empty() will do exactly what you need, though.
http://php.net/manual/en/function.isset.php
isset() will return FALSE if testing a variable that has been set to
NULL. Also note that a NULL byte ("\0") is not equivalent to the PHP
NULL constant.
Returns TRUE if var exists and has value other than NULL, FALSE
otherwise.

What is the best way to know is $_GET['example']=="somevalue"?

if((isset($_GET[example]))&&($_GET['example']=='somevalue')){ ... }
OR
if((!empty($_GET[example]))&&($_GET['example']=='somevalue')){ ... }
OR just
if($_GET['example']=='somevalue'){ ... }
I am asking that why I have seen many example where people check first if $_GET['example'] is set and then if $_GET['example']=='somevalue' ( first and second example above ).
I don't understand why not just use the last solution ( if $_GET['example']=='somevalue' then $_GET['example'] is obviously set ).
This question refers to any other variable ( $_POST, $_SERVER, ecc ).
if((isset($_GET[example]))&&($_GET['example']=='somevalue')){ ... }
Is the right one, you want to know that the "variable" exists (or is set) in order to use it. Empty just checks wether it has data of any kind or not.
For example:
<?php
$foo= 0;
if (empty($foo)) { // True because $foo is empty
echo '$foo is either 0, empty, or not set at all';
}
if (isset($foo)) { // True because $foo is set
echo '$foo is set even though it is empty';
}
if (isset($var)) { // FALSE because $var was not declared before
...
}
?>
The differences between isset and empty are subtle but important. They are most relevant when used alone. If you are checking that a variable exists and is a truethy value (e.g. any string that is not all spaces or 0s) you can use either interchangeably.
When to use isset
Use isset when it's important to know if the variable has been defined and is not null:
if (isset($maybeExistsMaybeNull)) {
// variable defined and is not NULL
}
When to use !empty
Use !empty when it's important to know if the variable has be defined and is truthy
if (!empty($mightBeEmpty)) {
// variable defined, and isn't "", " ", 0, "0" etc.
}
!empty is a great shorthand for exists and is something.
When to use array_key_exists
Use array_key_exists when it's important to know if the key exists and the value is of no importance:
if (array_key_exists('something', $array)) {
// $array['something'] exists, could be literally anything including null
}
When not to use isset
If your code looks like this:
if (isset($something) && $something) {
// code is shorter with !empty
}
When not to use !empty
If your code looks like this:
if (!empty($something) && $something === "") {
// you meant isset. this is unreachable.
}
Then you're writing code that can't be executed
Code that throws errors is error prone
Avoid writing code that issues notices/warnings that you are ignoring. For example in the question:
if((isset($_GET[example]))&&($_GET['example']=='somevalue')){ ... }
The first use of example is an undeclared constant. Or is it undeclared - what if you've got define('example', "foo"); somewhere else in the code.
if($_GET['example']=='somevalue'){ ... }
If the url doesn't contain ?example=.. that's going to issue a notice too.
Writing code without displaying errors means you can very easily miss mistakes like the first.
In context: isset and !empty are equivalent
For the example given, these two language constructs act exactly the same.
There is no case where one will act differently than the other, neither will issue a notice if the variable is undefined, and no measurable difference in performance between the two.
As others have said for checking things like $_GET and $_POST you would ideally want to use:
if ( isset($_GET['example']) && $_GET['example'] =='somevalue' ) {
// process data
}
So you always want to firstly make sure that the variable has been set (and not set to null) or in other words exists. Then proceed to check if the variable contains the data that you were expecting. If you try to make reference to a variable which doesn't exist (by not checking isset()) php will give you a notice saying 'undefined variable...etc etc'.
If you wanted to find out if a variable is set but are not concerned too much by what then you could use:
if ( !empty($_GET['example']) ) {
// process data
}
But I would be careful about using empty() on strings in this regard as empty can behave strangely with string data like '0' or ' '.
So I would always do the first one, to a) make sure the variable exists and b) is what you were expecting it to be.
This is something that you'll probably do a lot of and it helps to put together a class/functions which handles this checking for you so you dont have to do it everytime.
function checkValue($key, $value) {
if(array_key_exists($key, $_REQUEST)){
if ($_REQUEST[$key] == $value) {
return true;
} else {
return false;
}
} else {
return false;
}
}
I just use Request as a default instead of switching out (though it is preferable to switch in some cases between POST and GET for security (imo)).
Now you can just call this function anywhere
if (checkValue('Item', 'Tom') === true){} etc
the best is
if((isset($_GET[example]))&&('somevalue'==$_GET['example'])){ ... }
The difference between
'somevalue'==$_GET['example']
AND
$_GET['example']=='somevalue'
If you mistype the == and type = instead, the first notaion will raise an error to notify you.
if((isset($_GET[example]))&&($_GET['example']=='somevalue')){ ... }

PHP: testing for existence of a cell in a multidimensional array

I have an array with numerous dimensions, and I want to test for the existence of a cell.
The below cascaded approach, will be for sure a safe way to do it:
if (array_key_exists($arr, 'dim1Key'))
if (array_key_exists($arr['dim1Key'], 'dim2Key'))
if (array_key_exists($arr['dim1Key']['dim2Key'], 'dim3Key'))
echo "cell exists";
But is there a simpler way?
I'll go into more details about this:
Can I perform this check in one single statement?
Do I have to use array_key_exist or can I use something like isset? When do I use each and why?
isset() is the cannonical method of testing, even for multidimensional arrays. Unless you need to know exactly which dimension is missing, then something like
isset($arr[1][2][3])
is perfectly acceptable, even if the [1] and [2] elements aren't there (3 can't exist unless 1 and 2 are there).
However, if you have
$arr['a'] = null;
then
isset($arr['a']); // false
array_key_exists('a', $arr); // true
comment followup:
Maybe this analogy will help. Think of a PHP variable (an actual variable, an array element, etc...) as a cardboard box:
isset() looks inside the box and figures out if the box's contents can be typecast to something that's "not null". It doesn't care if the box exists or not - it only cares about the box's contents. If the box doesn't exist, then it obviously can't contain anything.
array_key_exists() checks if the box itself exists or not. The contents of the box are irrelevant, it's checking for traces of cardboard.
I was having the same problem, except i needed it for some Drupal stuff. I also needed to check if objects contained items as well as arrays. Here's the code I made, its a recursive search that looks to see if objects contain the value as well as arrays. Thought someone might find it useful.
function recursiveIsset($variable, $checkArray, $i=0) {
$new_var = null;
if(is_array($variable) && array_key_exists($checkArray[$i], $variable))
$new_var = $variable[$checkArray[$i]];
else if(is_object($variable) && array_key_exists($checkArray[$i], $variable))
$new_var = $variable->$checkArray[$i];
if(!isset($new_var))
return false;
else if(count($checkArray) > $i + 1)
return recursiveIsset($new_var, $checkArray, $i+1);
else
return $new_var;
}
Use: For instance
recursiveIsset($variables, array('content', 'body', '#object', 'body', 'und'))
In my case in drupal this ment for me that the following variable existed
$variables['content']['body']['#object']->body['und']
due note that just because '#object' is called object does not mean that it is. My recursive search also would return true if this location existed
$variables->content->body['#object']->body['und']
For a fast one liner you can use has method from this array library:
Arr::has('dim1Key.dim2Key.dim3Key')
Big benefit is that you can use dot notation to specify array keys which makes things simpler and more elegant.
Also, this method will work as expected for null value because it internally uses array_key_exists.
If you want to check $arr['dim1Key']['dim2Key']['dim3Key'], to be safe you need to check if all arrays exist before dim3Key. Then you can use array_key_exists.
So yes, there is a simpler way using one single if statement like the following:
if (isset($arr['dim1Key']['dim2Key']) &&
array_key_exists('dim3Key', $arr['dim1Key']['dim2Key'])) ...
I prefer creating a helper function like the following:
function my_isset_multi( $arr,$keys ){
foreach( $keys as $key ){
if( !isset( $arr[$key] ) ){
return false;
}
$arr = $arr[$key];
}
return $arr;
}
Then in my code, I first check the array using the function above, and if it doesn't return false, it will return the array itself.
Imagine you have this kind of array:
$arr = array( 'sample-1' => 'value-1','sample-2' => 'value-2','sample-3' => 'value-3' );
You can write something like this:
$arr = my_isset_multi( $arr,array( 'sample-1','sample-2','sample-3' ) );
if( $arr ){
//You can use the variable $arr without problems
}
The function my_isset_multi will check for every level of the array, and if a key is not set, it will return false.

PHP if statement issue when checking for variable value

I'm trying to just write a simple PHP if statement that checks if a custom field has anything entered into or if it has been left blank.
when it is blank it is meant to not print anything to the page,
if something is set in the custom field then it should create a li element with an a tag inside of it.
here is my code so far:
<ul class="externalLinks">
<? $emptycheck = get('linkname',2,1,0);
if (isset($emptycheck)){ ?>
<li><? echo get('linkname',2,1,0);?></li>
<? } else { '' } ?>
<li>Download a PDF of this project</li>
</ul>
The custom fields in this case are set by the wordpress admin (through the flutter plugin).
The issue I am having is simply that if the custom fields are left blank an empty
<li><a></a></li>
is created.
get('linkname',2,1,0) returns the field content obviously (this part works).
Any ideas would be much appreciated.
Thanks,
Jannis
Just because a variable is empty doesn't mean it's not isset().
You want to check if it's empty() or not.
$whatever = get('whatever',2,1,0)
if (! empty($whatever)){
//output your stuff
}
To be clear: isset() will just tell you if the variable name exists in the symbol table. empty() will return true when a variable is empty.
According to the documentation:
The following things are considered to
be empty:
"" (an empty string)
0 (0 as an integer)
"0" (0 as a string)
NULL
FALSE
array() (an empty array)
var $var; (a variable declared, but without a value in a class)
Edited: empty() is kind of special, and operates only on a regular variable. You can't test an expression (for instance, the return value of a function) with empty(). This is clearly documented on the manual page.
You're setting $emptycheck regardless, if the return value is falsy you might want
if ( $emptycheck ) {
} else {
}
Otherwise it will always evaluate to true. Or flip the logic around with a negation operator ( ! ) if it's the other way around.

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