Do you have a Github repository for this plugin?

I’m pretty sure that will work fine. But just in case it does not, feel free to send me a message so we can check what’s wrong.

Based on our tests, fixed discounts don’t work because the plugin has to pass them to the conversion functions first. That is, it’s not our multi-currency plugin that “intercepts” the discount, it’s the discount plugin that has to explicitly pass them (any plugin that handles any pricing has to interface with the multi-currency layer explictily).

What happens when you set a fixed discount is that the amount is taken as an absolute value. For example, if a shop’s base currency is USD and there is a discount of “10 USD”, the actual discount value becomes “10 <of the active currency>” (10 USD, 10 EUR, 10 GBP, and so on, depending on which currency is active). To prevent this, the value should be passed through a filter that our multi-currency layer provides, so that it’s converted to the active currency before it’s applied.

A further improvement, which most of our customers require, is to allow entering the discount in multiple currencies directly on the backend. For example, the discount could be:
– 10 USD
– 9 EUR
– <auto> GBP

Which means:
– When currency is USD, the discount is 10.
– When currency is EUR, the discount is 9.
– When currency is GBP, the discount is “10 USD converted to GBP, using the exchange rates“

Percentage discounts work out of the box, because a discount of 10% is “10% of whatever amount is in the cart”, the currency is irrelevant.

I see… What’s the currency plugin?

It’s a commercial plugin we developed, it’s called Currency Switcher. There isn’t a free version available, but we can send it to you if you would like to test it.

Alternatively, as I wrote initially, we can try to implement the integration ourselves, and send you a pull request for the changes. ??

Ok, here is what i suggest:
Since it’s not a widely used plugin, we can add a hook in our own code so external plugins may be able to modify the discounts amounts applied. What do you think?

Actually, there are thousands of sites running our plugin, it’s quite popular. ??

Since our Currency Switcher is an addition to the WooCommerce core, we can’t modify it to interact with all plugins on the market. Instead, we did what you suggested, and we already added filters that external plugins can hook into. It’s a very simple, yet effective API, designed precisely for plugins that handle discounts, addons, special products and so on to become multi-currency aware.
In summary, instead of “talking” to a single currency WooCommerce core, they just have to hook into the multi-currency layer as well.

Besides, to allow admins to enter a discount in each currency, the UI of the discounts plugin would have to be modified as well. This not something we would do from our side either (we can’t possibly “inject” fields in other plugins), we give authors the freedom to show the extra currency fields and store the additional values as they like.

It’s simpler than it seems, we also have code examples to get started. ??

But these fields will be useless for shops whithout a currency management plugin… So we’ll need a to check the plugins list for specific currency plugins like yours before displaying them. What do you think?

That’s the great part: the filters we provide allow for full compatibility with single currency configurations, without any extra check.

The key is simply to use a different mindset. Instead of showing “one field”, you would show “one field per available currency”. This means one field in single currency setups, and one or more in multi-currency setups. You don’t need a single “if”, it all works transparently by using filters. There isn’t any strict dependency, nor any extra check required to see if our plugin is installed. It just works, Thanks to our simple API. ??

I think we have a misunderstanding. This version of the plugin is free. That means anyone can use it. I looked for the plugins that can handle multiple currencies and i found 2 free ones. It’s useless to display multiple currencies fields for discounts if there is no active plugin on the installation to handle the currencies switch otherwise this can be very confusing to shop managers. So we need to be able to detect if that feature is required in order to display the fields you’re requesting. And we can’t do that if your plugin is not available (at least some features) as freebie. If we were talking about the free plugin i saw in the repository then we will integrate it because they are plugins used by a lot of customers for free and that can be really good for us to have that in the pro version. Do you understand what i mean?

No misunderstanding, I understood perfectly the first time. As I wrote, an integration would not display unnecessary fields, and there would be no need to add checks to determine if a plugin is installed or not.

Checking for the presence of one or the other plugin would be the wrong way to implement a transparent integration, as it would introduce a tight coupling with other plugins. Since the WooCommerce environment is infamous for the lack of backward compatibility (which, instead, we guarantee at every update), such tight coupling could break any time when one of the plugins is updated. Our approach allows for loose coupling, preventing issues in the future.

I reckon that the easiest way to show how that works will be what I described at the beginning. We can patch the discounts plugin ourselves, to show you how easy the integration is, then you can review the changes and integrate them in the main release.

Ok. Please do and send me the modified files so i can run a diff and check what has been done.