web

Documentation

Overview

Package web contains a small web framework extension.

Index

• func Decode(r *http.Request, val interface{}) error
• func GetTraceID(ctx context.Context) string
• func IsShutdown(err error) bool
• func NewShutdownError(message string) error
• func Param(r *http.Request, key string) string
• func Respond(ctx context.Context, w http.ResponseWriter, data interface{}, statusCode int) error
• func SetStatusCode(ctx context.Context, statusCode int) error
• type App
  • func NewApp(shutdown chan os.Signal, mw ...Middleware) *App
  • func (a *App) Handle(method string, group string, path string, handler Handler, mw ...Middleware)
  • func (a *App) ServeHTTP(w http.ResponseWriter, r *http.Request)
  • func (a *App) SignalShutdown()
• type Handler
• type Middleware
• type Values
  • func GetValues(ctx context.Context) (*Values, error)

Functions

func Decode

func Decode(r *http.Request, val interface{}) error

Decode reads the body of an HTTP request looking for a JSON document. The body is decoded into the provided value.

If the provided value is a struct then it is checked for validation tags.

func GetTraceID

func GetTraceID(ctx context.Context) string

GetTraceID returns the trace id from the context.

func IsShutdown

func IsShutdown(err error) bool

IsShutdown checks to see if the shutdown error is contained in the specified error value. [PS] Helper function to check the type of the error (Assert)

func NewShutdownError

func NewShutdownError(message string) error

NewShutdownError returns an error that causes the framework to signal a graceful shutdown. [PS] Factory function to create and return error

func Param

func Param(r *http.Request, key string) string

Param returns the web call parameters from the request.

func Respond

func Respond(ctx context.Context, w http.ResponseWriter, data interface{}, statusCode int) error

Respond converts a Go value to JSON and sends it to the client.

func SetStatusCode

func SetStatusCode(ctx context.Context, statusCode int) error

SetStatusCode sets the status code back into the context.

Types

type App

type App struct {
	// contains filtered or unexported fields
}

[PS] This struct represents a web application App is the entrypoint into our application and what configures our context object for each of our http handlers. Feel free to add any configuration data/logic on this App struct.

func NewApp

func NewApp(shutdown chan os.Signal, mw ...Middleware) *App

NewApp creates an App value that handle a set of routes for the application. [PS] pass 0 to many middleware functions

func (*App) Handle

func (a *App) Handle(method string, group string, path string, handler Handler, mw ...Middleware)

[PS] This is the outer layer. Actual treemux handle will be inside it Handle sets a handler function for a given HTTP method and path pair to the application server mux. [PS] group can be used for versioning v1, v2

func (*App) ServeHTTP

func (a *App) ServeHTTP(w http.ResponseWriter, r *http.Request)

ServeHTTP implements the http.Handler interface. It's the entry point for all http traffic and allows the opentelemetry mux to run first to handle tracing. The opentelemetry mux then calls the application mux to handle application traffic. This was setup on line 58 in the NewApp function.

func (*App) SignalShutdown

func (a *App) SignalShutdown()

SignalShutdown is used to gracefully shutdown the app when an integrity issue is identified.

type Handler

type Handler func(ctx context.Context, w http.ResponseWriter, r *http.Request) error

[PS] This handler function is used to overcome the limitation of httptreemux handler. This will be inner layer of onion A Handler is a type that handles an http request within our own little mini framework.

type Middleware

type Middleware func(Handler) Handler

[PS] middleware is the different concentric rings around a Handler function Middleware is a function designed to run some code before and/or after another Handler. It is designed to remove boilerplate or other concerns not direct to any given Handler.

type Values

type Values struct {
	TraceID    string
	Now        time.Time
	StatusCode int
}

Values represent state for each request.

func GetValues

func GetValues(ctx context.Context) (*Values, error)

GetValues returns the values from the context.