passing variable to my default.ctp cakephp

Question

i am newbie in cakephp ..actually i have two problems .. first one is I am setting variables in AppController in order to use them in default.ctp.

public function beforeRender(){

    $id = $this->Auth->user('idUser');

    $this->loadModel('Userinfo');
    $data= $this->Userinfo->find('all',array(
        'conditions' => array('Userinfo.User_id' => $id)
    ));

    foreach($data as $d){
        $product_purchase = $d['Userinfo']['product_purchase'];
    }

    $this->set('userinfo',$product_purchase);
}

so it is working fine when i use the variable into my default.ctp layout .. but the problem is when i logout from the the app then it displays this error on my login page

Undefined variable: product_purchase

What am I doing wrong? by the way i want to mention here is that in my login page i am not using default.ctp well which i think it has nothing to do with dat

the second problem is i want to show specific menu items for the specific user ... so i am doing this in my view page

<?php if ($userinfo == 1){ ?> 
  <li><a href="explorer.html" class="shortcut-medias" title="Media">Media</a> </li>
<?php }else{ //nothing }?>

value in userinfo is 2 .. but if else isnt working .. it is still displaying the menu

Answer 1

The variable product_purchase isn't initialized

If there is no results for the previous find call, the variable $product_purchase will not be defined triggering an undefined variable error. This will be the case if there is no logged in user:

public function beforeRender(){

    // will be null if there is no user
    $id = $this->Auth->user('idUser');

    // unnecessary find call if there is no user, returning no rows
    $this->loadModel('Userinfo');
    $data= $this->Userinfo->find('all',array(
        'conditions' => array('Userinfo.User_id' => $id)
    ));

    // will not enter this foreach loop as data is empty
    foreach($data as $d){
        $product_purchase = $d['Userinfo']['product_purchase'];
    }

    // $product_purchase is undefined.
    $this->set('userinfo',$product_purchase);
}

For the code in the question, just initialize the variable earlier:

public function beforeRender(){
    $product_purchase = null;

$producut_purchase may get overwritten

Note that if there is more than one row of data returned for this query:

foreach($data as $d){
    $product_purchase = $d['Userinfo']['product_purchase'];
}

The $product_purchase variable will only contain the value of the last row.

If there is only ever one result - use an appropriate method. Don't use find('all') - use find('first'). Or given the fact that only one field is being retrieved - directly use the field method:

$product_purchase = $this->Userinfo->field(
    'product_purchase', 
    array('Userinfo.User_id' => $id))
);