如何使用模型和控制器验证cakephp中的表单字段

Question

I have created a form which I need to validate using model and controller .Here is my form

index.ctp

    <?php echo $this->Form->create('Contact',array('url'=>array('controller'=>'contacts','action'=>'add'))); 

 echo $this->Form->text('name');

Model : Contact.php

class Contact extends AppModel
{
        var $name = 'Contact';
        var $useTable = false;

       public $validate = array(
        'name' => array(
            'alphaNumeric' => array(
                'rule'     => 'alphaNumeric',
                'required' => false,
                'message'  => 'Letters and numbers only'
            ),
            'between' => array(
                'rule'    => array('between', 5, 15),
                'message' => 'Between 5 to 15 characters'
            )
        )
    );
} 

Controller : ContactsController.php

public function add()
    {
         $this->Contact->validates();

            $this->request->data['Country']['country_name']=$this->request->data['Contact']['country'];

            $this->Country->saveall($this->request->data);

            $this->redirect('/Contacts/index/');

    }

I am trying to do the validation by googling but it seems difficult to me so if anyone could describe the process it would be a great help .My cakephp version is 2.3.8. I just need to validate this name field , as when I click in submit it will show this message in the form.

Answer 1

Your controller code should be like this The process of validation in CakePHP is like

1) as you have defined validation rules in CakePHP model public `$validates = array();`

2) when ever you do a save on particular model directly or through any association 
a callback method beforeValidate for that model gets called to validate the data which is being saved. 

3) once the data is validated then beforeSave callback is called after this save method is called. 

4) we can also validate the form input fields in controller using $this->Model->validates() but then while saving we have to disable the beforeValidate callback by doing 

$this->Model->save($data,array('validate'=>false));

Otherwise you will end validating the same data twice

your controller code should be somewhat like this.

public function add() {
        // here we are checking that the request is post method
        if ($this->request->is('post')) {
               $this->request->data['Country']['country_name']
                               = $this->request->data['Contact']['country'];
                // here we are saving data
            if ($this->Contact->saveAll($this->request->data)) {

                //here we are setting a flash message for user
                $this->Session->setFlash('your record has been added','success');

                $this->redirect(array('controller'=>'contacts','action' => 'index'));
            } else {
                //here we are setting a flash message for user for error if input are not          
                //validated as expected
                $this->Session->setFlash('sorry we could add your record','error');
            }

        }

    }

For more information you can always refer to http://book.cakephp.org/2.0/en/models/callback-methods.html