@LaurensGoedel

I think this is not a bug ...

proper usage would be to add a 2nd parameter (the 'prefix') to it, so this:

JModelLegacy::addIncludePath(JPATH_COMPONENT_ADMINISTRATOR.'/models/');
$productModel = JModelLegacy::getInstance('Product', 'StockModel');

should be:

$_prefix = 'StockModel';
JModelLegacy::addIncludePath(JPATH_COMPONENT_ADMINISTRATOR.'/models/', $_prefix);
$productModel = JModelLegacy::getInstance('Product', $_prefix);

Still the fact that it worked before is a B/C break ?

That seems to work indeed! But why did it work till 3.5.1 without the prefix?
The function inside JModelLegacy isnt' changed.

If something worked because of a bug and the bug is fixed it's unfortunate
but not a b/c issue

I confirm this behaved differently in J3.5.x,
i am afraid this is a B/C break,

• some software maybe using this without the prefix ?

Almost all usage of it in core files, that i could find
is making use of the $prefix when calling

JModelLegacy::addIncludePath()

But i found 1 case not using it (also 1 in com_admin)
https://github.com/joomla/joomla-cms/blob/staging/administrator/components/com_categories/helpers/categories.php#L148-L151

now because there is not a frontend model for it, no bug will manifest, if someone tries to use the categories helper from frontend

public static function addIncludePath($path = '', $prefix = '')

$prefix is an optional parameter. I was never using $prefix in my extensions, because it is optional. And I am sure that many developers also. If behavior without it was changed then it is a B/C break.

I'd like to investigate on this.

For people who are having similar issue with:

JModelLegacy::addIncludePath(JPATH_COMPONENT_ADMINISTRATOR . '/models/');
$productModel = JModelLegacy::getInstance('Product', 'StockModel');

Can you provide attach the output of the following code (Change the Model Prefix StockModel to your components prefix):

$paths   = array();
$paths[] = JModelLegacy::addIncludePath(null, '');
$paths[] = JModelLegacy::addIncludePath(null, 'StockModel');

JModelLegacy::addIncludePath(JPATH_COMPONENT_ADMINISTRATOR . '/models/');

$paths[] = JModelLegacy::addIncludePath(null, '');
$paths[] = JModelLegacy::addIncludePath(null, 'StockModel');

$productModel = JModelLegacy::getInstance('Product', 'StockModel');

$paths[] = JModelLegacy::addIncludePath(null, '');
$paths[] = JModelLegacy::addIncludePath(null, 'StockModel');

echo '<pre>';
print_r($paths);
echo '</pre>';

output of the code above:

Array
(
    [0] => Array
        (
            [0] => -webdir-/components/com_stock/models
        )

    [1] => Array
        (
            [0] => -webdir-/components/com_stock/models
        )

    [2] => Array
        (
            [0] => -webdir-/administrator/components/com_stock/models/
            [1] => -webdir-/components/com_stock/models
        )

    [3] => Array
        (
            [0] => -webdir-/components/com_stock/models
        )

    [4] => Array
        (
            [0] => -webdir-/administrator/components/com_stock/models/
            [1] => -webdir-/components/com_stock/models
        )

    [5] => Array
        (
            [0] => -webdir-/components/com_stock/models
        )

)

Please also check for

print_r(class_exists('StockModelProduct', false));

This should return false, if your backend model is supposed to load. If it returns true that means your front-end model has already been loaded and there will be no effect of addModelPath or addIncludePath anymore.

Well, on little investigation I found it to be caused by the fix I did with #9409. However, that is a real fix, it has to be that way.

On further investigation, I found that earlier (before that fix) the model paths were stored as:

Array
(
    [stockModel] => Array
        (
            [0] => /-/components/com_stock/models
        )
    [] => Array
        (
            [0] => /-/components/com_stock/models
        )
)

Notice lowercase "s" in stockModel. When looking up for StockModel (uppercase "S") using:

$productModel = JModelLegacy::getInstance('Product', 'StockModel');

It was never found and hence fallback to "" prefix (i.e. path with no prefix) was used. That's why,

JModelLegacy::addIncludePath(JPATH_COMPONENT_ADMINISTRATOR . '/models/');

always worked. Now it doesn't because When looking up for StockModel using the same code above it finds the correct path array and uses it already.

Summary

The fix is correct and the behaviour is appropriate. However, if we think we should provide B/C support here too, its fine and simple too. We'd just ignore the case of the prefix in addIncludePath.

EDIT: Sorry, that case-insensitivity would be good, but still won't provide the B/C. Only removing prefix from the call at JControllerLegacy would do this.

But I won't do it unless advised. May be @brianteeman can decide the best here.

@wilsonge your advice please on moving forward with this

@wilsonge @rdeutz it appears from the comments that there was a b/c break BUT its been almost a year now so can we just close this?

Hello,
It seems it's not fixed permanently..
J 3.9.11
In site view I'm not able to load the admin model (I can load other views admin model instead, other component models too):

Array
(
[0] => Array
(
[0] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_fields/models
[1] => /Library/WebServer/Documents/web/testmodel/components/com_test/models
[2] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_actionlogs/models
)

[1] => Array
    (
        [0] => /Library/WebServer/Documents/web/testmodel/components/com_test/models
    )

[2] => Array
    (
        [0] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_test/models/
        [1] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_fields/models
        [2] => /Library/WebServer/Documents/web/testmodel/components/com_test/models
        [3] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_actionlogs/models
    )

[3] => Array
    (
        [0] => /Library/WebServer/Documents/web/testmodel/components/com_test/models
    )

[4] => Array
    (
        [0] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_test/models/
        [1] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_fields/models
        [2] => /Library/WebServer/Documents/web/testmodel/components/com_test/models
        [3] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_actionlogs/models
    )

[5] => Array
    (
        [0] => /Library/WebServer/Documents/web/testmodel/components/com_test/models
    )

)

With or without the famous prefix... no way.

Please provide a full reproduction scenario. Dumping a debug output here provides absolutely no information on how someone can recreate your issue (and write automated tests to prevent it from reoccurring if confirmed to be a bug). There is a reason it’s generally suggested to open new items instead of randomly commenting on closed issues, part of it being the issue template which asks important questions to help people triage the issue.

Hello,
I just try to use the admin model in site side, same view name, let's say 'order', so I have 'MycomponentModelOrder' in the backend and 'MycomponentModelOrder' in the frontend.
Now, in the view 'view.html.php' (frontend) I want to load the backend model.
I tried with (in different attempt):
$test = JModelLegacy::addIncludePath(JPATH_COMPONENT_ADMINISTRATOR.'/models/', $_prefix);
var_dump($test) returns:
Array
(
[0] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_test/models
[1] => /Library/WebServer/Documents/web/testmodel/components/com_test/models
)
and JModelLegacy::getInstance('Order', $_prefix);
loads the frontend model

$test = JModelLegacy::addIncludePath(JPATH_ADMINISTRATOR.'/components/com_test/models/');
var_dump($test) returns:
Array
(
[0] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_test/models
[1] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_fields/models
[2] => /Library/WebServer/Documents/web/testmodel/components/com_test/models
[3] => /Library/WebServer/Documents/web/testmodel/administrator/components/com_actionlogs/models
)
and JModelLegacy::getInstance('Order', $_prefix); returns frontend model

$test = JModelLegacy::addIncludePath(JPATH_COMPONENT_ADMINISTRATOR.'/models, 'TestModel');
var_dump($test) returns:
Array
(
[0] => /Library/WebServer/Documents/web/bpplan/administrator/components/com_bpplan/models
[1] => /Library/WebServer/Documents/web/bpplan/administrator/components/com_fields/models
[2] => /Library/WebServer/Documents/web/bpplan/components/com_bpplan/models
[3] => /Library/WebServer/Documents/web/bpplan/administrator/components/com_actionlogs/models
)
and JModelLegacy::getInstance('Order', $_prefix); loads the frontend model.

All tested with and without $_Prefix = 'TestModel'; (which I confess I never used so far...)

At the same time, all the above work with different model name and even different components/models, so basically it seems in the front end I'm not able to load the admin model of the same component in same view/model name.

So, to reproduce the scenario, open the front view.html.php and try to load the relative model but from admin side.
I hope you've got the picture.