E-commerce_Shopping Cart Sharing

Requirements:
can be added before login, shopping cart.
Merge shopping cart after login.
Multiple platforms use the same shopping cart.
Solution:
The shopping cart information is temporarily stored in the cookie, and the information is merged with the database data after logging in.
Note that multiple platforms use different domain names, so the cookies are different. It is necessary to establish a user center service to manage the shopping cart information in a unified manner. Different domain names are used. jsonp accesses the user center across domains, uses the unified cookie of the user center to save the shopping cart information, and realizes shopping cart sharing.