Limit order quantity to multiple of minimum order

-- HikaShop version -- : Essential 2.2.3
-- Joomla version -- : 3.2.1
-- PHP Version 5.3.27

I have a food product priced at $20 per 100g, and the minimum order quantity is 300g. Also I need to limit the order quantity to multiples of the minimum order. i.e. customer's orders can only be 300g, 600g, 900g and up.

Setting "Price" = 20; "Minimum quantity per order" = 3 can only limit the order quantity starting at 300g. I would like to modify the "+" and "-" buttons so that each press of the buttons will increase/decrease the order quantity by the value of the "minimum quantity per order", here is 3 in this example.

Hi,
If you want all your product to be sold per quantity of 3, the solution will probably be to edit the file "administrator/components/com_hikashop/helpers/cart.php" and change these lines :

					function hikashopQuantityChange(field,plus,max,min){
						var fieldEl=document.getElementById(field);
						var current = fieldEl.value;
						current = parseInt(current);
						if(plus){
							if(max==0 || current<max){
								fieldEl.value=parseInt(fieldEl.value)+1;
							}else if(max && current==max){
								alert(\''.JText::_('NOT_ENOUGH_STOCK',true).'\');
							}
						}else{
							if(current>1 && current>min){
								fieldEl.value=current-1;
							}
						}
						return false;
					}

					function hikashopQuantityChange(field,plus,max,min){
						var fieldEl=document.getElementById(field);
						var current = fieldEl.value;
						current = parseInt(current);
						if(plus){
							if(max==0 || current<max){
								fieldEl.value=parseInt(fieldEl.value)+3;
							}else if(max && current==max){
								alert(\''.JText::_('NOT_ENOUGH_STOCK',true).'\');
							}
						}else{
							if(current>1 && current>min){
								fieldEl.value=current-3;
							}
						}
						return false;
					}

I don't need this buying restriction in quantity apply to all products.

Some products priced by boxes. Some products priced by bottles. They are fine with the default setting of increment=1. However, for products priced by weight, they are all sold by unit of 100g for comparison sake. Amongst them, some food products are weighted over 100g per piece and must be sold as a multiple of its average weight.

Will there be way to change the increment for a few products only, not the whole site.

Hi there,

It's getting very picky, Hikashop doesn't propose this feature so far.
If you have knowledge in php and html, you can adapt the code mohamed give you to be applied only on specific product.
Or you can ask on our commercial job forum if someone is willing to do it.

Hi there, thank you for the prompt reply.

How can I adapt Mohamed's code to apply on a specific product. In what way can a specific product be referred to? Should all the work be done in the file administrator/components/com_hikashop/helpers/cart.php?

Most of the modification will have to be done here.
You will have to change the behaviour of the funciton according to the product id so it doesn't affect every product.
You can hardcode the list of product or even had something in the Hikashop backend to select your product.
Anyway it definitely require some good php skills.

To tackle the problem in another approach. Is there a way to not allow an order to proceed to checkout if the quantity is not set at one of the allowed values, which in my case above is 3, 6, 9 and up..

Same answer, you either have to edit the checkout code to check the product and the quantity or you can create a plugin to perform that check.

Hi Mohamed,

we had modified your suggested to make the increase and decrease button always add a multiple of the min order quantity.

function hikashopQuantityChange(field, plus, max, min) {
	var d = document, fieldEl = d.getElementById(field);
	if(!fieldEl) return false;
	var current = parseInt(fieldEl.value);
	if(current === NaN) return false;
	if(plus) {
		if(max == 0 || current < max) {
			fieldEl.value = current + min;
		} else if(max && current == max) {
			alert(\''.JText::_('NOT_ENOUGH_STOCK',true).'\');
		}
	} else if(current > 1 && current > min) {
		fieldEl.value = current - min;
	}
	return false;
}

Hi, so we have changed the quantity input to "show select" and now we have the dropdown with values multiples of the minimum order. The only problem is that when one selects a different characteristic, the quantity input dropdown is not populated with the complete list, just the first value. We have tried different characteristics selection method but it doesn't change anything.

Hi,

we have updated to version 3.1.1. It still doesn't work with characteristics. We have some template overrides of the product view. Probably we need to update these too. Which files are to update?

Hi, we have found the issue. Under Hikashop configuration > Display > General Display Options > Use Chosen Library is set to YES then the dropdown list for the quantity is not loaded correctly. Set Use Chosen Library to NO and the quantity list displays correctly when changing the characteristic.

Hi, I don't know what other people think of the new system, those who were using multiples of minimum order quantity. Here are out thoughts.

1) drop down lists to achieve multiples of the minimum quantity is not a use friendly as being able to click the plus or minus button
2) being limited to a maximum 15 with the drop down lists is annoying because if the product can be bought singly you often might want more than 15 such as 100. One to a hundred in a drop down list is not very nice. Even with multiples of the minimum order 15 might not be enough. For example you have minimum order 24 pieces and you want 1152 pieces that is 48 items in the drop down list. Again not user friendly.

Just my thoughts.

Thanks, James

Hi Nicolas,

while I agree entirely with you answer I was speaking specifically about cases where shop owners want to see multiples of the min quantity per order, i.e. 6, 12, 18, 24, 30 etc

With the legacy cart system (prior to hikashop 3+) it was possible to use the input field along with the modification proposed by Mohamed Thelji near the start of this thread. However with the new cart system in hikahops 3+ the only way to be able to sell multiple values of the minimum quantity is to use the dropdown input method with the inconveniences as outlined in my previous post.

So is there a way with the new cart system to sell multiples of the minimum order quantity the input field box?

James

Cool feature "Display view files" under advanced config.

As you can imagine not all products will have same master boxes. It could be any number. You example examples works fine if they all have master box of 6.

How do you handle the situation in which for example, even the same category, a products has master box 6 and another product has master box 12?