Hi @lewis2413,

I manage to reproduce the issue with PS1.7.6.0 & PS1.7.5.2.
I attached a screen record
https://drive.google.com/file/d/1kTDiNC19Xk5kd0m-vhijwK9axB8laymI/view
I used this script to update the position of a product

<?php
/**
 * Created by PhpStorm.
 * User: khouloud.belguith
 * Date: 30/09/17
 * Time: 11:58
 */
define('DEBUG', true);
ini_set('display_errors','on');
define('PS_SHOP_PATH', 'http://shop.com');
define('PS_WS_AUTH_KEY', 'Key');
require_once('PSWebServiceLibrary.php');
$webService= new PrestaShopWebservice(PS_SHOP_PATH, PS_WS_AUTH_KEY, DEBUG);
$id =  23; 
$category_id = 3;
$xml = $webService->get(array('resource' => 'products', 'id' => $id));
unset($xml->product->manufacturer_name);
unset($xml->product->quantity);

$product = $xml->children()->children();
$product->name->language[0][0] = "Produit webservice";

$product->description->language[0][0] = "Description produit webservice";

$product->price = 1.121;
$product->position_in_category = 1;
//I don't update XML, i just resend it here
$opt['putXml'] = $xml->asXML();                  
$opt['id'] = $id;
$opt['category_id'] = $category_id;
$opt['resource'] = 'products';

$xml = $webService->edit($opt);

echo "DONE";

I’ll add this to the debug roadmap so that it’s fixed. If you have already fixed it on your end or if you think you can do it, please do send us a pull request!
Thanks!

Hi good afternoon,

@khouloudbelguith Do you have any feedback about this problem? i´m contacting to you because we need some solution about this bug..

I'll hope your comments

thanks advance

Hi @lewis2413,

Sorry, this issue is not yet.
There are some major issues to solve before this one.
But PrestaShop is an open source project, so it can be solved before if someone submits a pull request to solve it.
Thanks!

I'm not sure it's related to this problem but the function setWsCategories() in classes/Product.php looks to work in a wrong way to me.
No matter what you send in position_in_category, the datas in category_product table (sorted by product id) is deleted and recreated as if it was sorted by the category id.
Feel free to check that by yourself, it's only my observations, maybe I got something wrong.

I'm not a pro in PrestaShop code so I won't dare to submit a pull request but I hope those infos will help to fix this issue.

I've made a PR normally handling this bug : #31342

I am getting this bug too... The category is not empty, and I can't set the position_in_category for the new product, because I get this error:

Error on creating product: This call to PrestaShop Web Services failed and returned an HTTP status of 500. That means: Internal Server Error - (Code 135): Non puoi impostare una posizione maggiore del numero complessivo dei prodotti nella categoria, che comincia da 1.

Position in category is 4 and in the category I have already 3 products.
I have found why: the PR #16697 changed the condition in the Product.php class.
For a new product that cannot work, because its position will be always bigger of the current count.
I will try to fix it myself and see, but I am new to Prestashop.

The problem is that I get a new product without any position_in_category set and the result is that in the cart I can't update the quantity of that product, I get an error (in the developer console of the browser) that the product is not available. In the front end the quantity returns back to the previous value.
If I save the product in the backed, I can update the quantity in the cart and I notice that position_in_category has been set.

@afdev82 If you want to spend some times you can juste use my previous PR #31342 and fix the bug that was reported by the QA Team, the logic was already validated.

@TomLorenzi Yes, I have already seen that PR, but in my opinion the real problem in that function is that it cannot update a row that doesn't exist in the DB (in the case of a new product created with the Webservice: https://github.com/PrestaShop/PrestaShop/pull/31342/files#diff-e94a594ba740485c7a4882b333984d3932a2f99c0d6d0005620745087cce7a10R7195

I don't think I could find a general solution that could work, because I don't know so much Prestashop.
As I can see the problem with a completely new product is that in the setWsPositionInCategory function we don't have yet the product ID, then I can't create the row for the position in the category_product table.

Maybe someone with more experience could help here, for the moment I am just creating the row in my class, where I know (after the product creation) the product ID.