Difference between #5 and #4 of Using the jamselect widget with min and max values

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Title
Using the jamselect widget with min and max values
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Category
How-tos
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Tags
Form validation, Widgets
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Content
The problem
-----------
I needed to have users select from a list of keywords, in this example they must
select at least two keywords but they cannot select more than six.

The keywords will be stored in a text field in a comma delimited format.  The
keywords will be created by the site administrator.

In a very timely fashion the
[jamselect](http://www.yiiframework.com/extension/jamselect/
"jamselect") widget showed up, thanks volkmar!

The widget does not provide min/max filtering so I will implement a custom rule.


First put the widget in a form
------------------------------
This is my implementation.

~~~
[php]
<?php	
$this->widget(
    'application.extensions.asmselect.JAMSelect',
    array(
        'selected'=>$this->getKeywords($model->keywords),
		'data'=>CHtml::listData(Keywords::model()->findAll(),'word', 'word'),
                'htmlOptions'=>array(
            'title'=>'Select up to six keywords',
            'name'=>'keywordArray'
        ),
        'animate'=>true
    ));
?>
~~~

A few things to notice
----------------------
The widget is located in `/protected/extensions not
/protected/extensions/widgets`, I only point this out for people who aren't sure
where to put things.  You have quite a bit of flexibility on where you locate
widgets and components. It doesn't makes sense to me to create another folder in
extensions but perhaps on a very large project it would.

The dropdown list data is being pulled from a table that has only two fields,
`id` and `word`, since I want to select the word from the list and store exactly
the same value in the database I need a key=>value array that looks like
`word'=>'word`.

The `$_POST` data will contain an array of selected values, this will be in
`$_POST['keywordArray']`

Lets look at the controller (create)
------------------------------------
~~~
[php]
public function actionCreate()
{
    $model=new EventAbstract;

    $this->layout = '//layouts/column1';

    // Uncomment the following line if AJAX validation is needed
    // $this->performAjaxValidation($model);

    if(isset($_POST['EventAbstract']))
    {
        $model->attributes=$_POST['EventAbstract'];

        // I better do a check in case no keywords were selected
        $keywordArray = (!isset($_POST['keywordArray']) ? array() :
$_POST['keywordArray']); 

        // now I either have an array of keywords or an empty array
        // send the array to a function to format the keywords in a 
        // comma delimited format
        $this->setKeywords($model,'keywords',$keywordArray);

        // it's all done but not yet validated
        if($model->save())
            $this->redirect(array('view','id'=>$model->id));
    }

    $this->render('create',array('model'=>$model));
}
~~~

Here is the function that formats the keywords
----------------------------------------------
Remember the keywords are suppled by the admin so I am not doing any checking
here for capitals or illegal characters.

~~~
[php]
public function setKeywords($model,$field,$keys)
{
    $model->$field = (empty($keys) ? null : implode(',',$keys));
}
~~~

Update record
-------------
And when we perform an update on the record we have to turn our comma delimited
field back into an array, so similarly.

~~~
[php]
public function getKeywords($delimited)
{
    $keys = explode(',',$delimited);
    return $keys;
}
~~~

Rules
-----
And now for the rules (in the model file)

~~~
[php]
public function rules()
{
    // NOTE: you should only define rules for those attributes that
    // will receive user inputs.
    return array(
        // other rules are here
       
array('keywords','keywordCount','skipOnError'=>true,'maxKeys'=>6,'minKeys'=>2),array('keywords',
'keywordCount', 'skipOnError'=>true, 'maxKeys'=>6, 'minKeys'=>2),
        // keywords is the field in the table currently holding the submitted
value
        // $model->keywords
        // keywordCount is the function (in the model) that will do the
validation
        //
        //skipOnError, maxKeys and minKeys are all parameters that will be 
        //sent to the validation function other rules
    );
}
~~~

The validation function
-----------------------
~~~
[php]
public function keywordCount($attribute,$params)
{
    $keys = explode(',',$this->$attribute);
    // check if there are keywords exist
    if(!$this->$attribute)
    {
        $this->addError($attribute,'<strong>If you need to add a
keyword please contact the administrator</strong>');
    } 
    // check if there are enough keywords
    if(count($keys) < $params['minKeys'])
    {
        $this->addError($attribute,'Please choose at least
'.$params['minKeys'].($params['minKeys'] > 1 ? ' keywords' :' keyword'));
    } 
    // check if there are too many keywords
    if(count($keys) > $params['maxKeys'])
    {
        $this->addError($attribute,'You have chosen too many keywords max =
'.$params['maxKeys']);
    }	 
}	
~~~
Now the user can select between 2 and 6 keywords.

doodle