Developing a Form Director Class - The form builder class
(Page 3 of 4 )
In order to get the schema imposed by the builder pattern nearer to completion, it's convenient to recall quickly the signature of the respective "FormBuilder" class, along with its corresponding abstract parent.
Below I have listed the full source code that corresponds to these two classes:
// define abstract 'AbstractFormBuilder' class
abstract class AbstractFormBuilder{
abstract function getForm();
}
// define concrete 'FormBuilder' class
class FormBuilder extends AbstractFormBuilder{
private $html=array();
private $action;
private $method;
public function __construct($action='',$method='post'){
// setup form attribute
$this->action=!$action?$_SERVER['PHP_SELF']:$action;
$this->method=$method!='post'||$method!='get'?
'post':$method;
}
// add form element
public function addElement($type='text',$attributes=array
('name'=>'default'),$options=array()){
if(!$elem=new FormElement($type,$attributes,$options)){
throw new Exception
('Failed to instantiate '.$type.' object');
}
$this->html[]=$elem->getHTML();
}
// add form part
public function addFormPart($formPart='<br />'){
$this->html[]=trim($formPart)==''?'<br />':$formPart;
}
// get web form
public function getForm(){
$formOutput='<form action="'.
$this->action.'" method="'.$this->method.'">';
foreach($this->html as $html){
$formOutput.=$html;
}
$formOutput.='</form>';
return $formOutput;
}
}
All right, now I firmly believe that the two classes listed above are fresh in your mind. If they aren't yet, let me explain briefly how they fit into the builder pattern schema. As you'll see, the prior "FormBuilder" class is tasked with generating the whole online form, in accordance with some input parameters passed to its constructor, such as the $method and $action variables.
In addition, the class also comes with the "addElement()" method, which is pretty handy for adding different form elements to the general structure. In this way it allows for the dynamic generation of regular online forms. Of course, the remaining class methods speak for themselves, therefore I'll skip rapidly over them.
At this stage, and based on the set of classes that were listed earlier, the schema established by the pattern builder is very close to completion. After all, I have on one hand a "FormElement" class (in this case referenced as the target element) that obviously renders different form controls, while on the other hand there's the form builder class that you saw before, responsible for using the mentioned form elements to create the complete online form.
So, the question that comes up now is, what's the missing piece here? Obviously, the element that remains undefined is a form director class, which will instruct to the form builder on how the online form in question must be constructed. Indeed, that makes a lot of sense!
Regarding the definition of the corresponding form director class, in the upcoming section I'll show you its complete signature. If you want to see how this brand new class looks, please keep reading.
Next: Defining a form director class >>
More PHP Articles
More By Alejandro Gervasio
