In my proje开发者_开发百科ct all of my view classes are extensions of a base view class which handles all common aspects to the views, including error messages. In one of the view extensions I am creating an instance of another 'helper' class which may need to output error messages.
Is there any way that I can reference my addError
method from the parent of the class that created the instance of the helper class, directly from within a method of the helper class itself?
e.g.
class baseview { ... public function addError($message) { ... } ... } class pageview extends baseview { ... $helper = new helper(); ... } class helper { ... public function myFunction($var) { if( $var ) { ... } else { theClassThatInstantiatedMe::addError('Error Message') } } ... }
~ OR ~
Could someone please suggest a better way to structure my system to better handle this type of situation?
2 simple solutions are:
Store the parent class in the helper class:
class pageview extends baseview {
...
$helper = new helper($this);
...
}
class helper {
function __construct($parent)
{
$this->_parent=$parent;
}
...
$this->_parent->addError("...");
}
Othwerwise make the addError function public and static so that you can call it in the helper class without store the parent class instance:
class baseview {
...
static public function addError($message) {
...
}
...
}
class helper{
...
baseview::addError("...");
}
From your example, I would have supposed that you meant baseview to be used universally, and so "baseview::addError('Error Message');"
But from the text, I gather that there may be differnt classes. In that case, you are going to have to pass a reference to the creating class into the helper, like this:
class pageview extends baseview {
...
$helper = new helper($this);
... }
class helper { protected $creator; ... public function myFunction($creator, $var) {
$this->creator = $creator;
if( $var ) { ... }
else { $creator->addError('Error Message') }
}
...
}
If you want clean code, you should separate wiring (object creation) and logic.
Here is THE pdf all coders should have read at least once: Writing Testable Code
It is a pdf found on Misko Hevery's blog (A google "clean code" evangelist).
If you prefer videos, you can check these: Misko's conferences at Google
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