Paypal Checkout logic is wrong when it is the only available payment method

[nick4501]

Describe the bug
When the only available payment method is Paypal Checkout, the whole payment process does not work, as the Select Payment Method checkout step is automatically skipped, preventing the user from being able to click on the dedicated Paypal button. NOTE: the Paypal button DOES appear when there are multiple payment methods available and the user selects Paypal.

To Reproduce
Steps to reproduce the behavior:

1. Remove all payment methods except for Paypal Checkout.
2. Add a product to the cart and then continue to the checkout page.
3. After entering shipping/billing address, the payment selection page is skipped, so there is no way to be redirected to Paypal to authorise the payment. If the user continues all the way to the end of the standard checkout process and clicks Confirm, instead of being redirected to the Paypal website, the following error is displayed: PayPal Error (PayPalCheckoutState.PaypalOrderId)

Expected behavior
We should either force the Payment Method step to be displayed (which will allow the user to click on the Paypal button next to the payment method), or correctly handle this scenario at the end of the checkout process.

Desktop (please complete the following information):

• OS: (All)
• Browser: (All)

[Michael-Herzog]

Hi,
There is already a hidden setting which prevent this behaviour. Please go to Admin / Configuration / Settings / All setting
Search for the setting name bypasspaymentmethodselectionifonlyone and set it to False.
Regards,
Michael

[nick4501]

Hi @Michael-Herzog, @muratcakir. Sorry to re-open this ticket. I've changed the setting and the payment method step is now displayed so I'm able to click on the Paypal button, but after logging into Paypal and confirming the payment, I get redirected back to the store website with an error saying "Error: data is not defined". Everything looks to be correctly configured in the Paypal plugin, so I'm wondering why this is now happening. Is it a known bug?

[nick4501]

I believe this may be because we're not passing a "custom_id" field on the Paypal request (see screenshot from Paypal dashboard). Am I right in thinking that we use this custom_id on the return to our site, to retrieve the session/cart?

[Michael-Herzog]

Hi,
currently in branch 5.0.5 there are no know bugs and the plugin is working fine in multiple shops.
Are you working in another branch or did you adapt the code?
Regards,
Michael

[nick4501]

Hi Michael. I'm running v5.0.4.0, but haven't made any changes to the Paypal code. What are your thoughts on the missing custom_id field?

Thanks,
Nick

[Michael-Herzog]

Hi Nick,
custom_id should be filled. But I can't tell if this is causing the error. We also fixed lots of othe stuff in version 5.0.5 so please perform an update.
Regards,
Michael

[nick4501]

Thanks Michael - I've just had a look at a long list of bug fixes in 5.0.5 and it certainly sounds like it's worth upgrading! I'll do this today and report back.

Also: if you take a look at PayPalHttpClient.cs, you can see that the orderGuid parameter is optional (see attached screenshot). It's this parameter that is used to populate custom_id...

[nick4501]

@Michael-Herzog, Thanks very much - upgrading to v5.0.5 fixed this!