Using array_key_exists() on objects is deprecated when using paginate() with object target

[ThauEx]

When using the paginate() method of the Paginator class with an object as target, it throws the following deprecation:

array_key_exists(): Using array_key_exists() on objects is deprecated. Use isset() or property_exists() instead in vendor/knplabs/knp-components/src/Knp/Component/Pager/Pagination/AbstractPagination.php line 163

It can be fixed with the following change:

    public function offsetExists($offset): bool
    {
        if ($this->items instanceof \ArrayIterator) {
            return array_key_exists($offset, iterator_to_array($this->items));
        }

-        return array_key_exists($offset, $this->items);
+        return isset($this->items[$offset]);
    }

Since paginate has the following description for the $target argument:

• @param mixed $target anything what needs to be paginated
  I would say this is a bug.

Should I open a PR for that?

[garak]

Can you provide an example of using paginate with an object?

[ThauEx]

I don't have any sample code, but it could be something like ArrayCollection from the doctrine collections.

[garak]

That's already working, as it's working with QueryBuilder objects and with many other objects.

[ThauEx]

I know that it works with ArrayCollection, but php 7.4 deprecated using array_key_exists on objects. This is the reason, why I opened this issue.
Together with the KnpPaginatorBundle and Twig, offsetExists gets called somewhere and triggers the mentioned deprecation message.

[garak]

A PR is welcome

[ThauEx]

Done 🙂