Constarints for product quantities?

[ccppll]

Thank you, maybe using that module I'll be able to adapt it to my needs.
Thank you, both of you, for your help.

[schoolboy]

If you succeed, I'd really like to know the solution, as I too am building a wineshop with the same challenge!

[ccppll]

In the product editing page in admin, you can set

Product Qty Units: []

to 6, and customers will only be allowed to buy that product in groups of 6.

That's not what I want, the customer can buy 3 products A 1 products B and 1 product C, the important thing is that that sum is a multiple of 6 (only for some products, not for all).

[bunyip]

Interesting tip, I'll try it! I think this could be ok, but now I would like to go a bit further: is it possible to add an hidden attribute to a product in order to be able to choose which products must be taken into account when doing this calculation? I mean, my goal is to check if the user has bought a number of products multiple of 6, but not all products must be subject to this limit. I could hard-code this list in the class, but it would be better if I could select them in the admin section.

The best way to approach this would be to create a new product type that uses the same handler page as a normal product. Then you use that new product type only for items that have the qty 6 limit, rather than try to use a hidden attribute. Your custom code then just needs to check the product type, rather than against a list of product ids or extra fields/attributes.

I don't think the qty-units setting in admin will help you, because that sets the order units just for the single product, which is not what you are trying to achieve.

[ccppll]

[In the product editing page in admin, you can set

Product Qty Units: []

to 6, and customers will only be allowed to buy that product in groups of 6.

I don't know for sure if this forbids changing the quantity to an odd number once in the shopping cart, but I think that aspect is covered too.]

Nevermind, eyes too bleary to see the "different kinds of wine" aspect of your question... no wonder knowledgeable people weren't giving that answer... :) Time for bed.

The best way to approach this would be to create a new product type that uses the same handler page as a normal product. Then you use that new product type only for items that have the qty 6 limit, rather than try to use a hidden attribute. Your custom code then just needs to check the product type, rather than against a list of product ids or extra fields/attributes.

I don't think the qty-units setting in admin will help you, because that sets the order units just for the single product, which is not what you are trying to achieve.

Mmmm, could I have a sample of this?

thanks

[bunyip]

To add the new product type to your database, run this query from your SQL Patch page in admin:

INSERT INTO `product_types` ( `type_id` , `type_name` , `type_handler` , `type_master_type` , `allow_add_to_cart` , `default_image` , `date_added` , `last_modified` ) VALUES ('', 'Product - Wine', 'product', '1', 'Y', '', NOW( ) , NOW( ));

sample function codes I've used for checking the product type:

// function to lookup product_type for product-wine
function get_wine_product_type_id() {
    global $db;
	
	$sql = "select type_id from " . TABLE_PRODUCT_TYPES . " where type_name = 'Product - Wine'";
	$type_query = $db->Execute($sql);
	$wine_product_type = $type_query->fields['type_id'];
	
	return $wine_product_type;
}

// function to lookup a product's product_type
function get_products_product_type_id($products_id) {
    global $db;
	
	$sql = "select products_type from " . TABLE_PRODUCTS . " where products_id = '" . (int)$products_id . "'";
	$type_query = $db->Execute($sql);
	$product_type_id = $type_query->fields['products_type'];
	
	return $product_type_id;
}

Then you could change the product type of your existing products that need to be this type directly from phpmyadmin - replace the value in the products_type field of the products table with the newe value (if you haven't previously added a new product type, the new one will be 6)

[ccppll]

To add the new product type to your database, run this query from your SQL Patch page in admin:

INSERT INTO `product_types` ( `type_id` , `type_name` , `type_handler` , `type_master_type` , `allow_add_to_cart` , `default_image` , `date_added` , `last_modified` ) VALUES ('', 'Product - Wine', 'product', '1', 'Y', '', NOW( ) , NOW( ));

sample function codes I've used for checking the product type:

// function to lookup product_type for product-wine
function get_wine_product_type_id() {
    global $db;
	
	$sql = "select type_id from " . TABLE_PRODUCT_TYPES . " where type_name = 'Product - Wine'";
	$type_query = $db->Execute($sql);
	$wine_product_type = $type_query->fields['type_id'];
	
	return $wine_product_type;
}

// function to lookup a product's product_type
function get_products_product_type_id($products_id) {
    global $db;
	
	$sql = "select products_type from " . TABLE_PRODUCTS . " where products_id = '" . (int)$products_id . "'";
	$type_query = $db->Execute($sql);
	$product_type_id = $type_query->fields['products_type'];
	
	return $product_type_id;
}

So type_handler is product, that is, it uses the same product class? Or should I override it? And, regarding the functions you posted, where could i add them? And where to call them?

Thanks

[bunyip]

yes, if you keep the type_handler the same, you don't need to create a whole new bunch of files in admin or the catalog.
If for example you set the handler to product_wine, you'd need to duplicate the folder admin/includes/modules/product, and add new pages and templates on the catalog side. You'd really only want to do that if you intended to add specific product fields into the database for standardizing display, or perhaps adding new product filters, etc.
As for the functions, add them into a new file (eg wine_functions.php) in the includes/functions/extra_functions folder.
You'd call them when writing your code for quantity checking:
eg:

if (get_products_product_type_id($products_id) == get_wine_product_type_id()) { 
check quantities code
} else {
do nothing
}

[ccppll]

Hi! After some discussion with the costumer, he decided to change the way to handle things. He now wants to send only groups of 6 bottles of the same wine. So, now I just use quantity units to 6 and that's all. I would like to know if it would be possible to change a bit the way it's done. For example, why does zen cart lets me add 5 bottles to my cart if I must buy 6? Also, wouldn't it be possible to add the product unit instead of the single bottle? I mean, since I must add 6 or 12 etc bottles, but I would like to keep the price of a single bottle etc, is there a way to add not single bottles but groups of 6 bottles? So the number in the product quantity would be the number of units...

Thanks!

[Ajeh]

If you set the Units to 6, then the add to cart quantity box is 6 ...