fn-serverless/api/server/special_handler.go

package server

import (
	"net/http"

	"context"
	"github.com/gin-gonic/gin"
	"github.com/iron-io/functions/api/models"
)

type SpecialHandler interface {
	Handle(c HandlerContext) error
}

// Each handler can modify the context here so when it gets passed along, it will use the new info.
// Not using Gin's Context so we don't lock ourselves into Gin, this is a subset of the Gin context.
type HandlerContext interface {
	// Context return the context object
	Context() context.Context

	// Request returns the underlying http.Request object
	Request() *http.Request

	// Datastore returns the models.Datastore object. Not that this has arbitrary key value store methods that can be used to store extra data
	Datastore() models.Datastore

	// Set and Get values on the context, this can be useful to change behavior for the rest of the request
	Set(key string, value interface{})
	Get(key string) (value interface{}, exists bool)
}

func (s *Server) AddSpecialHandler(handler SpecialHandler) {
	s.specialHandlers = append(s.specialHandlers, handler)
}

func (s *Server) UseSpecialHandlers(ginC *gin.Context) error {
	c := &SpecialHandlerContext{
		server:     s,
		ginContext: ginC,
	}
	for _, l := range s.specialHandlers {
		err := l.Handle(c)
		if err != nil {
			return err
		}
	}
	return nil
}