web

Documentation

Overview

Package web provides a minimal framework for common HTTP related tasks.

Index

• Constants
• func Decode(r *http.Request, val interface{}) error
• func NewRequestError(err error, status int) error
• func Respond(ctx context.Context, w http.ResponseWriter, data interface{}, statusCode int) error
• func RespondError(ctx context.Context, w http.ResponseWriter, err error) error
• type App
  • func NewApp(log *log.Logger, mw ...Middleware) *App
  • func (a *App) Handle(method, url string, h Handler, mw ...Middleware)
  • func (a *App) ServeHTTP(w http.ResponseWriter, r *http.Request)
• type Error
  • func (err *Error) Error() string
• type ErrorResponse
• type FieldError
• type Handler
• type Middleware
• type Values

Constants

const KeyValues ctxKey = 1

KeyValues is how request values or stored/retrieved.

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 NewRequestError

func NewRequestError(err error, status int) error

NewRequestError wraps a provided error with an HTTP status code. This function should be used when handlers encounter expected errors.

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 RespondError

func RespondError(ctx context.Context, w http.ResponseWriter, err error) error

RespondError sends an error reponse back to the client.

Types

type App

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

App is the entrypoint into our application and what controls the context of each request. Feel free to add any configuration data/logic on this type.

func NewApp

func NewApp(log *log.Logger, mw ...Middleware) *App

NewApp constructs an App to handle a set of routes. Any Middleware provided will be ran for every request.

func (*App) Handle

func (a *App) Handle(method, url string, h Handler, mw ...Middleware)

Handle associates a handler function with an HTTP Method and URL pattern.

It converts our custom handler type to the std lib Handler type. It captures errors from the handler and serves them to the client in a uniform way.

func (*App) ServeHTTP

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

ServeHTTP implements the http.Handler interface.

type Error

type Error struct {
	Err    error
	Status int
	Fields []FieldError
}

Error is used to pass an error during the request through the application with web specific context.

func (*Error) Error

func (err *Error) Error() string

Error implements the error interface. It uses the default message of the wrapped error. This is what will be shown in the services' logs.

type ErrorResponse

type ErrorResponse struct {
	Error  string       `json:"error"`
	Fields []FieldError `json:"fields,omitempty"`
}

ErrorResponse is the form used for API responses from failures in the API.

type FieldError

type FieldError struct {
	Field string `json:"field"`
	Error string `json:"error"`
}

FieldError is used to indicate an error with a specific request field.

type Handler

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

Handler is the signature used by all application handlers in this service.

type Middleware

type Middleware func(Handler) Handler

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 {
	StatusCode int
	Start      time.Time
}

Values carries information about each request.