 PHP Page 5 - Building a PHP 5 Form Processor: Using the Form Processor Package |
The complete application at a glance: listing the complete code of the form processor - PHPWelcome to the last part of the series “Building a PHP 5 form processor.” In three parts, this series goes through the development of an extensible form processor package in PHP 5, explaining its benefits and demonstrating its implementation.
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To summarize, here’s the complete source code for the form processing package: // class formElement // creates form elements class formElement{ private $html=''; public function __construct($type='text',$attributes=array ('name'=>'default'),$options=array()){ // check for <input> elements if(preg_match("/^ (text|radio|checkbox|password|hidden|submit|reset|button|image| file)$/",$type)){ $openTag='<input type="'.$type.'" '; $closeChar=' '; $closeTag='/>'; } // check for <textarea> and <select> elements else if(preg_match("/^(textarea|select)$/",$type)){ $openTag='<'.$type.' '; $closeChar='>'; $closeTag='</'.$type.'>'; } else{ throw new Exception('Invalid element type'); } if(!is_array($attributes)||count($attributes)<1){ throw new Exception('Invalid number of attributes for <'.type.'> element'); } // loop over element attributes $elemAttributes=''; foreach($attributes as $attribute=>$value){ if(empty($attribute)||empty($value)){ throw new Exception('Invalid attribute or value for <'.type.'> element'); } // check for 'required' attribute - add client-side validation $attribute=='required'?JSGenerator::addValidation ($attributes ['name'],$value):$elemAttributes.=$attribute.'="'.$value.'" '; } // check for <select> options $selOptions=''; if(count($options)>0){ foreach($options as $value=>$text){ if(empty($value)||empty($text)){ throw new Exception('Invalid value or text for <'.type.'> element'); } $selOptions.='<option value="'.$value.'">'.$text.'</option>'; } } // build form element(X)HTML output $this->html.=$openTag.trim ($elemAttributes).$closeChar.$selOptions.$closeTag; } // return complete (X)HTML public function getHTML(){ return $this->html; } } // class JSGenerator // generates client-side validation functions abstract class JSGenerator{ private static $js=array(); // load external JavaScript validating functions public function initializeFunctions(){ self::$js['ext']='<script language="javascript" src="functions.js"></script>'; } // add JavaScript validating function to selected field public function addValidation($fieldName,$valData){ if(!is_array($valData)){ throw new Exception('Invalid client-side validation array'); } $obj='document.getElementsByTagName("form")[0].elements ["'.$fieldName.'"]'; // obtain client-side validating function & error message list($valFunction,$errorMessage)=$valData; self::$js['int'].='if (!'.$valFunction.'('.$obj.',"'.$errorMessage.'")){'.$obj.'.focus ();return false};'; } // return JavaScript code public function getCode(){ return self::$js['ext'].'<script language="javascript">function validate(){'.self::$js['int'].'}</script>'; } } // class formValidator // performs server-side form validation class formValidator{ private $errors=array(); public function __construct(){} // validate empty field public function validateEmpty($field,$errorMessage,$min=4,$max=32){ if(!isset($_POST[$field])||trim($_POST[$field]) ==''||strlen($_POST[$field])<$min||strlen($_POST[$field])>$max){ $this->errors[]=$errorMessage; } } // validate integer field public function validateInt($field,$errorMessage){ if(!isset($_POST[$field])||!is_numeric($_POST[$field]) ||intval($_POST[$field])!=$_POST[$field]){ $this->errors[]=$errorMessage; } } // validate numeric field public function validateNumber($field,$errorMessage){ if(!isset($_POST[$field])||!is_numeric($_POST[$field])){ $this->errors[]=$errorMessage; } } // validate if field is within a range public function validateRange($field,$errorMessage,$min=1,$max=99){ if(!isset($_POST[$field])||$_POST[$field]<$min||$_POST [$field]>$max){ $this->errors[]=$errorMessage; } } // validate alphabetic field public function validateAlphabetic($field,$errorMessage){ if(!isset($_POST[$field])||!preg_match("/^[a-zA-Z] +$/",$_POST[$field])){ $this->errors[]=$errorMessage; } } // validate alphanumeric field public function validateAlphanum($field,$errorMessage){ if(!isset($_POST[$field])||!preg_match("/^[a-zA-Z0-9] +$/",$_POST[$field])){ $this->errors[]=$errorMessage; } } // validate email public function validateEmail($field,$errorMessage){ if(!isset($_POST[$field])||!preg_match ("/.+@.+\..+./",$_POST[$field])||!checkdnsrr(array_pop(explode ("@",$_POST[$field])),"MX")){ $this->errors[]=$errorMessage; } } // private method 'windnsrr()' for Windows systems private function windnsrr($hostName,$recType=''){ if(!empty($hostName)){ if($recType=='')$recType="MX"; exec("nslookup -type=$recType $hostName",$result); foreach($result as $line){ if(preg_match("/^$hostName/",$line)){ return true; } } return false; } return false; } // check for errors public function checkErrors(){ if(count($this->errors)>0){ return true; } return false; } // return errors public function displayErrors(){ $errorOutput='<ul>'; foreach($this->errors as $err){ $errorOutput.='<li>'.$err.'</li>'; } $errorOutput.='</ul>'; return $errorOutput; } } // class formGenerator // builds up the web form class formGenerator{ private $html=array(); private $action; private $method; public function __construct($action='',$method='post'){ // setup form attributes $this->action=empty($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; } // display form public function display(){ $formOutput='<form action="'.$this->action.'" method="'.$this->method.'">'; foreach($this->html as $html){ $formOutput.=$html; } $formOutput.='</form>'; // load global JavaScript checking functions JSGenerator::initializeFunctions(); // append JavaScript code to general (X)HTML output $formOutput.=JSGenerator::getCode(); return $formOutput; } } Wrapping up In this article, I went through the makings of an extensible form processing library, for use either in PHP 5, or –- with minor modifications -- in PHP 4. If you’re serious about taking PHP to more complex levels of development, I encourage you to grab the proper theory behind processing forms through the object-oriented paradigm, and then make your own way, either by extending the package I developed or by picking up an existing one. As always, the choice is up to you. Meet you in the next PHP tutorial!
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