code: public function addField(FormField $field){
  
  		$this->fields[]=$field;
  
  		if($field->getName()==null){
  			$field->setName('name_'.count($this->fields));
  		}
  
  		if($field->getId()==null){
  			$field->setId('id_'.count($this->fields));
  		}
  
  		if($field instanceof FileField){
  			$this->formTags['enctype']='multipart/form-data';
  		}
  
  	}
docs: Add form field
  
  @param FormField $field