Difference in accessing variables in views - arrays

Question

I've two controllers one is "Upload" which deals with images uploads and other is "Page" whid deals with the creation of pages of CMS now if in my "Upload" controller I load both the models i.e 'image_m' which deals with image upload and "page_m" which deals with the pages creation I've highlighted the relevant code my problem is if I access the variables in the view
$this->data['images'] = $this->image_m->get(); sent by this I can access in foreach loop as "$images->image_title, $images->image_path" etc
But the variable sent by this line ***$this->data['get_with_images'] = $this->page_m->get_no_parents();*** as $get_with_images->page_name, $get_with_images->page_id etc produces given error
A PHP Error was encountered
Severity: Notice
Message: Trying to get property of non-object
Filename: upload/index.php
Line Number: 20
what is the difference between these two access levels one for $image & other for $get_with_images because I can only access its values as $get_with_images
class Upload extends Admin_Controller {
public function __construct() {
parent::__construct();
***$this->load->model('image_m');
$this->load->model('page_m');***
}
public function index($id = NULL) {
//var_dump($this->data['images'] = $this->image_m->get_with_images());
//$this->data['images'] = $this->image_m->get_with_images();
***$this->data['images'] = $this->image_m->get();***
$this->data['subview'] = 'admin/upload/index';
if ($id) {
$this->data['image'] = $this->image_m->get($id);
count($this->data['image']) || $this->data['errors'][] = 'Page Could not be found';
}
$id == NULL || $this->data['image'] = $this->image_m->get($id);
/*this calls the page_m model function to load all the pages from pages table*/
***$this->data['get_with_images'] = $this->page_m->get_no_parents();***

Answer 1

You are not posting all your code so its hard to tell but is it because you used $this-> in the controller, but you haven't done the same thing in the view?
In this case i would recommend not using $this-> because its not necessary. Also its much better to check for errors etc when you call the model so do something like
if ( ! $data['images'] = $this->image_m->get($id) ) {
// Failure -- show an appropriate view for not getting any images
// am showing $data in case you have other values that are getting passed
$this->load->view( 'sadview', $data ); }
else {
// Success -- show a view to display images
$this->load->view( 'awesomeview', $data ); }
so we are saying if nothing came back - the ! is a negative - then show the failure view. Else $data['images'] came back, and it will be passed to the view. note i have not had to use $this-> for anything and it won't be needed in the view.
Would also suggest using separate methods - have one method to show all images and a separate method like returnimage($id) to show an image based on a specific validated $id.
====== Edit
You can access as many models as you want and pass that data to the View. You have a different issue - the problem is that you are waiting until the View to find out - and then it makes it more difficult to figure out what is wrong.
Look at this page and make sure you understand the differences between query results
http://ellislab.com/codeigniter/user-guide/database/results.html
When you have problems like this the first thing to do is make a simple view, and echo out directly from the model method that is giving you problems. Its probably something very simple but you are having to look through so much code that its difficult to discover.
The next thing is that for every method you write, you need to ask yourself 'what if it doesn't return anything?' and then deal with those conditions as part of your code. Always validate any input coming in to your methods (even links) and always have fallbacks for any method connecting to a database.

Answer 2

On your view do a var_dump($get_with_images) The error being given is that you are trying to use/access $get_with_images as an object but it is not an object.
or better yet on your controller do a
echo '<pre>';
var_dump($this->page_m->get_no_parents());
exit();
maybe your model is not returning anything or is returning something but the data is not an object , maybe an array of object that you still need to loop through in some cases.