Paypal AngellEye DoExpressCheckout - 数据不匹配

Question

I am just starting to use the AngellEye library with php, in particular the SetExpressCheckout which calls DoExpressCheckoutPayment.

I have built my cart and posted to Paypal using the SetExpressCheckout functionality.

All appears to go through properly, but I had left the DoExpressCheckoutPayment as it was with the original basket as in the demo. It is this basket which goes through to Paypal, not my basket.

Is this correct? I thought it would have noticed the original basket is not what is being finally processed and thrown an error. I know I can rebuild the basket in DoExpressCheckoutPayment, but I thought they should match to catch any interfering which might have taken place between my site and Paypal - or is that my job to check? (Fine if it is!)

Incidentally, it did throw an error when the currency code's did not match - I had to change them both to GBP

If I have misunderstood how it should work, my apologies.

Answer 1

In general practice:

The contents and values in SetExpressCheckout need to match DoExpressCheckoutPayment within the allowed realm (you are allowed to change the values and items of the purchase on a user... within reason).

Why it maybe didn't complain:

The reason it probably didn't completely complain, is the difference between the 'demo data' and 'actual' was within the allowed for a seller to change. And it simply accepted the differences for the final transaction (except as you noted, currency code cannot change!).

See, when you initially send a user to paypal with information such as:

• Buy Product #4
• For $9.99
• USD

Then that user 'agrees to those conditions and authorizes the transaction'. You get the authorization code to continue with the capture. However it is at this point the seller has a margin for change (although not recommended as you easily upset customers). Where you could do a final transaction of:

• Buy Product #9282 (switch the product on the user)
• For $11.99 (raise the price a bit, claiming 'taxes added' or whatever)
• USD (must remain the same as you pointed out)

Although thats still 'acceptable' for the PayPal system... it may not be proper customer business.

Concern on interference:

Your concern for "interfering which might have taken place" should not be one. The transaction code, the merchant id, and secret are all used to prevent that kind of middle-man-meddling. And since the Set and Do actions are both server-side (not javascript), the user could not alter those values directly themselves to get a different product for a lower price.

Hope that helps clarify your concerns/questions.