Braintree js/php full working example working like Paypal Express Checkout? -

i'm trying understand if it's convenient client switch paypal express checkout braintree, find latter way complicated , hard understand (terrible docs, reference good).

documentation lacks complete working examples, pages needed can change api credentials , works. fundamental system/api logic , workflow.

i have checkout system customer's data , basket_id, form redirect customer paypal passing these data, , once customer completes payment paypal calls url on server sending data sent plus transaction id, , way mark basket_id/order paid , assign transaction. , no sensitive payment data typed or pass through our server/network.

how on braintree js+php? full , complete sandbox working example can change credentials , have working code understand logics? faster reading quite confusing documentation.

thanks!