DataMapper ORM v1.8.0

[eluser]DocO[/eluser]
Apologies if this has been covered - not hitting on the right search terms if it is.

I'm new to DataMapper, and got it working relatively well enough for discrete objects. Now I'm trying to be able to create/edit objects that have relationships.

For example, I've got a Location model, that defines particular locations. It has_many another model, called Rack, which has_one Location.

In the controller/view for a Rack, I need to be able to create a selector of available Locations. I have a single view, called "edit.php", that handles both creating a Rack and editing it, and is fed off two functions - edit() and save() in the controller. If validation fails in save(), it loads up edit.php with the info again and the validation errors.

To generate the selector, I created a simple function in the Location model:

Code:

function get_list() {
                $list = $this->select('id,name')->order_by('name')->get();
                $mylist = array();
                foreach ($list as $obj) {
                        #echo $obj->id." ".$obj->name."<p>\n";
                        $mylist[$obj->id] = $obj->name;

                }
                return $mylist;
        }

In the controller for Racks, I simply create the Location object and call the function:

Code:

# Need list of locations
                $locs  = new Location();
                $data['location_list'] = $locs->get();

In the view, as long as there is validation error, I can reference the array in a foreach loop, and everything is fine - i.e., this simplified loop outputs what I expect:

Code:

<?php foreach ($location_list as $loc): ?>
            &lt;?php echo "ID $loc->id<p>\n";?&gt;
            &lt;?php echo "NAME $loc->name<p>\n";?&gt;
          &lt;?php endforeach ?&gt;

But if there is ANY validation error, apparently $location_list is completely different, and I get errors about trying to get the property of a non-object with reference to the $loc->id and $loc->name references.

I'm certainly not doing something right, but I can't understand why it works except if there is a validation error.