Blog posts tagged with 'Expressions'

The GetOrders() customer extension method has been around since Shipping Director 1.13 (for nopCommerce 3.10), but we've never blogged about it.  Here's a couple of possible scenarios  (you may need to put the expression in different configuration fields depending on your needs).

Example: Prior orders containing 2 or more products from a particular vendor:

  Customer.GetOrders().Count(OrderItems.Any(Product.VendorId = 1)) > 2

Example: 10% discount (by using Surcharge Expression) if any (paid) orders in the last 45 days

    Integer PaymentStatus_Paid 30
    Customer.GetOrders().Any(CreatedOnUtc > DateTime.UtcNow.AddDays(-45) and PaymentStatusId = [PaymentStatus_Paid]) ? -[$Rate]*0.10 : 0

Example: Free Shipping for Add On Order (i.e. there's a prior order that's not yet shipped)

    Integer ShippingStatus_NotYetShipped  20
    OptionExit   Free Shipping for Add On Order    Customer.GetOrders().Any(ShippingStatusId = [ShippingStatus_NotYetShipped])     0

Be sure your expression is of the correct type whether assigned to a variable, or used in one of the Expression fields of a record.  Here are the types for the various Expression Fields:

Expressions are created by referencing variables that you define, or the underlying attributes of the Shopping Cart.  Expressions are built using variables and properties of the shipping request (e.g. Customer, Items collection, etc.).   Simple expressions just use typical operators like "+", "-", "and", "or", etc.  Queries use a variant of Linq syntax (no lambda symbol "=>" required).  Queries are applied to collections to "extract" the items in the collection that meet the query criteria.

When variable names are used in expressions, they must be enclosed in square brackets - e.g. [ZipCode3].  Variables can be boolean, string, decimal, integer, etc.  Query expressions and Attributes are referenced without enclosing brackets.  Most attributes are "objects" that themselves contain other attributes.  Some attributes are collections (lists), that can contain 0 or more other objects.  Developers having a familiarity with the nopCommerce shopping cart object and linq syntax certainly have an advantage when creating expressions, but the syntax is not that hard to grasp given some examples, and future blogs will discuss the cart,, and provide more examples.  Here are some examples that may commonly be used:

(Update: 12/12/2012 - see this for more about Variable and Expression Data Types )

(Update: 12/20/2021 - Customer.CustomerRoles won't work in 4.x and above.   Use Customer.GetCustomerRoles() to get the full collection, or to check a specific role, use helper property  Customer.IsInRole("role system name") )