DMZ 1.7.1 (DataMapper OverZealous Edition)

[eluser]lsemel[/eluser]
Hi Phil,
I was thinking about what the best way to integrate DataMapper model validation with regular CI form validation. I ended up writing an extension to the form validator in CI that lets you process forms involving DataMapper models in only a few lines of code. Assuming you have a DataMapper object Status that has its own validations, and your form's fields match the fields from Status, you can write this:

Code:

$status = new Status();
$status->get_by_id($status_id_to_update);
$this->form_validation->set_model($status);
# Add any additional form validation rules here
if ($this->form_validation->run($this)) {
      $model->save();
}

Here's the full code:

Code:

<?php

/**
* This form validation class extends the one that comes with Code Igiter to solve
* a few problems:
* - The Code Igniter one does not work well with Modules.  This gives the validation
*   run() function an extra parameter to indicate what class contains any
*   custom validation methods.
* - Form validation from Datamapper is completely separate from form validation
*   Code Igniter, and this unites them.  Call $this->form_validation->set_model($dm_object)
*   to have the form validator include the data model's validations along with
*   any rules you set up directly
* - This also copies data from the form into the model, so it doesn't have to be done
*   manually.  You can validate and save a model's 'text' field like this
*
*   $status = new Status();
*   $status->get_by_id($status_id_to_update);
*   $this->form_validation->set_model($status,array('text'));
*   if ($this->form_validation->run($this)) {
*      $model->save();
*      $this->form_validation->clear();
*      $this->data->message = 'Your item was saved';
*   }
*
*  Any error messages from the model will appear using the regular form_error()
*  helper.  The fields used in the form must match the field names of the model
*  - A clear() method is provided which will clear out any data submitted by the
*    post, in cases where the form results are shown on the same page as the form
*    itself
*/
class MY_Form_Validation extends CI_Form_Validation {
    var $model;
    var $model_fields = array();

    /**
     * Sets the error delimiters the way we want them on this site
     */
    function __construct() {
        parent::__construct();
        $this->set_error_delimiters('<div class=\"error\">','</div>');
    }

    /**
     * Call this to validate on the given model.  The model's fields will be set from the
     * contents of the post.  Specify an array of fields to set, otherwise all the
     * fields from the post will be set in the model.  The model's validation rules
     * will be called and added to the form validation object as if they had been
     * set up using the usual Code Igniter way
     *
     * This can also be called with a dummy model (e.g. new Account()) if you want
     * to ensure that the fields don't get saved
     */
    function set_model(&$model,$fields = array()) {
        $this->model =& $model;
        if (is_string($fields)) $fields = preg_split('/\s*,\s*/',$fields);
        $this->model_fields = $fields;
    }

    /**
     * Modification needed to work with Modules
     * See: http://ellislab.com/forums/viewthread/92212/P90/#578755
     */
    function run($module = '', $group = '') {
        (is_object($module)) AND $this->CI =& $module;

        // CodeIgniter convention is to return false if nothing was posted
        if (!$_POST) return false;
        
        // Skip CI's validiton if nothing was posted, or if there are no validation rules
        $result = ($_POST && (count($this->_config_rules) > 0 || count($this->_field_data) > 0)) ? parent::run($group) : true;
  
        // Perform the model's own validation
        $model_result = $this->model? $this->validate_model($this->model) : true;
        return $result && $model_result;
    }

    /**
     * Clears out all the posted data
     */
    function clear() {
        $this->_field_data = array();
    }

    /**
     * Sets an error message on a particular field, which will be accessible
     * via the form_error() helper
     *
     * @param <type> $field
     * @param <type> $message
     */
    function set_error($field,$message) {
        $this->_field_data[$field]['error'] = $message;
        $this->_error_array[$field] = $message;
    }


    /**
     * Given a DataMapper object, run validations on it and add any additional error messages to the form
     * This way we can use one validation mechanism.  Returns true or false if the model is valid
     * Form fields are pulled from the POST
     */
    function validate_model(&$model) {
        $ci =& get_instance();

      
        $model->error_prefix = $this->_error_prefix;
        $model->error_suffix = $this->_error_suffix;

        if (is_callable(array($model,'validate'))) {

            // Populate the model with the posted fields
            while (list($k,$v) = each($_POST)) {
                if ((!$this->model_fields) || in_array($k,$this->model_fields)) {
                    $model->$k = $v;
                }
            }
            $model->validate();
            if (!$model->valid) {
                $errors = (array)($model->error);
                unset($errors['all']);
                unset($errors['string']);
                while(list($k,$v) = each($errors)) {
                    if ($v && !$this->error($k)) {
                        $this->set_error($k,$v);
                    }
                }
            }
            return $model->valid;
        }
        trigger_error("The object provided is not a Datamapper model");
    }



}

?&gt;

Is there a better way to integrate the two distinct types of validation?