Controllers

Controller is responsible for handling incoming request, validate user inputs, calls appropriate application logic behind and returns the response to that request. The response would be different content types based on request such as HTML, JSON, XML, Text, Binary, File, etc.

Table of Contents

• How to create a Controller?
• How to create a Nested Controller?
• Controller provides access to

How to create a Controller?

A Controller is type struct that embeds the *aah.Context (Note: this is not a standard package context.Context).

// AppController embeds *aah.Context
type AppController struct {
  *aah.Context
}

// UserController embeds *aah.Context
type UserController struct {
  *aah.Context
}

How to create a Nested Controller?

aah supports nested controllers, the important difference is while nesting controller in another controller it would be non-pointer embed.

// AppController embeds *aah.Context
type AppController struct {
  *aah.Context
}

// UserController embeds AppController as nested.
type UserController struct {
  AppController
}

Controller provides access to

• Request and Response - Use Reply builder to compose response.
• Subject Instance (aka User) - ctx.Subject()
• Session Instance
• I18n messages
• Route URLs
• Reply Builder

Route URLs

aah provides a simple way to create route URL using route name defined in routes.conf.

Examples

// let's say route named `login` has path `/login.html`
RouteURL("login")

// Output
"//<host-address>/login.html"


// let's say route named `user_info` has path `/v1/users/:userId`
RouteURL("user_info", 100001)

// Output
"//<host-address>/v1/users/100001"


// let's say route named 'product_info' has path `/product/:productId`
RouteURLNamedArgs("product_info", map[string]interface{}{
  "id": "5564HFGFG56207",
  "lang": "es",
})

// Output
"//<host-address>/product/5564HFGFG56207?lang=es"