$this->_getParam in Zend Framework and empty()

Question

So I'm submiting a form and I'm trying to check if a field is empty or not and I do this:

if(empty($this->_getParam('my_field')))

And It doesn't work, But this works if I just use $_POST['my_field]

<b>Fatal error</b>: Can't use method return value in write context in....

How should I do this with $this->_getParam in order to work? since I guess is not such a good option to use $_POST on a framework.

Answer 1

This is your problem: Can't use method return value in write context

Here's a good explanation why have to do this: Can't use method return value in write context

To use empty() you would have to first get the return value

$field = $this->_getParam('my_field');
if(empty($field)){
  //is empty
}

(Update: This is not an issue for PHP versions >= 5.5) empty($this->_getParam('my_field')) would work just fine.

Answer 2

empty - like isset - is not a real function, instead it's a language construct. So you can only use variables as its only argument (no expressions, no function results).

But, you can use a temporary variable:

$my_field = $this->_getParam('my_field');
if(empty($my_field))
....

Answer 3

The other answers are correct. An alernative would be to provide a default to your call to _getParam(), such as null. Then you could call

is_null($this->_getParam('myfield',null))

This method might be preferable, because Zend already determines that parameter's emptiness.

Answer 4

You can use temporary variable

$field = $this->_getParam('my_field');

if(empty($field)){
  //you code here
}