Ports

Ports describe the format of an incoming or outgoing stream or HTTP endpoint.
They are used to automatically serialize and deserialize communications to a convenient structure for your application.

The term "Ports" is taken from Hexagonal Architecture, where it used to describe

... dedicated interfaces to communicate with the outside world. They allow the entry or exiting of data to and from the application.

-- Hexagonal Architecture, Medium

go-msx uses two types of ports, with many overlapping options:

• Input Port: describes an HTTP request or incoming Stream Message
• Output Port: describes an HTTP response or outgoing Stream Message

Declaration

Ports are defined using go structures, consisting of a series of fields. Each field consists of three parts:

1. Name: The name by which you can access the struct member in go code.

2. Type: The type of the field to which the data will be converted. These types fall into one of a few categories, to simplify conversion:

   • Scalar: Any simple single-valued (eg string, int, uuid, bool)
   • Array: A sequence of scalars
   • Object: A dictionary of scalars with string keys
   • File: An uploaded file
   • FileArray: A sequence of uploaded files

3. Tags: A set of annotations of the struct field, describing attributes like source/destination, index, validation, optionality, etc.

Example

type outputs struct {
    Code   int          `resp:"code"`
    Body   api.Response `resp:"body"`
    Error  api.Error    `resp:"body" error:"true"`
}