PHP: how to check if an object's properties have values? - php

Question

I use this to check if an object has properties,
function objectHasProperty($input){
return (is_object($input) && (count(get_object_vars($input)) > 0)) ? true : false;
}
But then I want to check further to make sure all properties have values, for instance,
stdClass Object
(
[package] =>
[structure] =>
[app] =>
[style] =>
[js] =>
)
Then I want to return false if all the properties have empty values. Is it possible? Any hint and ideas?

Answer 1

There are several ways of doing this, all the way up to using PHP's reflection API, but to simply check if all public properties of an object are empty, you could do this:
$properties = array_filter(get_object_vars($object));
return !empty($properties);
(The temporary variable $properties is required because you're using PHP 5.4.)

Answer 2

For deep inspection and a more advanced handling I'd go for something like the following which is easily extended. Consider it a follow up answer to dev-null-dweller's answer (which is perfectly valid and a great solution).
/**
* Deep inspection of <var>$input</var> object.
*
* #param mixed $input
* The variable to inspect.
* #param int $visibility [optional]
* The visibility of the properties that should be inspected, defaults to <code>ReflectionProperty::IS_PUBLIC</code>.
* #return boolean
* <code>FALSE</code> if <var>$input</var> was no object or if any property of the object has a value other than:
* <code>NULL</code>, <code>""</code>, or <code>[]</code>.
*/
function object_has_properties($input, $visibility = ReflectionProperty::IS_PUBLIC) {
set_error_handler(function(){}, E_WARNING);
if (is_object($input)) {
$properties = (new ReflectionClass($input))->getProperties($visibility);
$c = count($properties);
for ($i = 0; $i < $c; ++$i) {
$properties[$i]->setAccessible(true);
// Might trigger a warning!
$value = $properties[$i]->getValue($input);
if (isset($value) && $value !== "" && $value !== []) {
restore_error_handler();
return true;
}
}
}
restore_error_handler();
return false;
}
// Some tests
// The bad boy that emits a E_WARNING
var_dump(object_has_properties(new \mysqli())); // boolean(true)
var_dump(object_has_properties(new \stdClass())); // boolean(false)
var_dump(object_has_properties("")); // boolean(false)
class Foo {
public $prop1;
public $prop2;
}
var_dump(object_has_properties(new Foo())); // boolean(false)
$foo = new Foo();
$foo->prop1 = "bar";
var_dump(object_has_properties($foo)); // boolean(true)

Answer 3

Depending on what do you consider as 'empty value' you may have adjust the callback function that removes unwanted values:
function objectHasProperty($input){
return (
is_object($input)
&&
array_filter(
get_object_vars($input),
function($val){
// remove empty strings and null values
return (is_string($val) && strlen($val))||($val!==null);
}
)
) ? true : false;
}
$y = new stdClass;
$y->zero = 0;
$n = new stdClass;
$n->notset = null;
var_dump(objectHasProperty($y),objectHasProperty($n));//true,false