- Add handler logic

Author: kietnguyentuan69

handler.go

@@ -0,0 +1,85 @@
+package code
+
+import (
+	"context"
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"strings"
+)
+
+const InternalServerError = "Internal Server Error"
+
+type CodeHandler struct {
+	Loader         CodeLoader
+	Resource       string
+	Action         string
+	RequiredMaster bool
+	LogError       func(context.Context, string)
+	LogWriter      LogWriter
+}
+
+func NewDefaultCodeHandler(loader CodeLoader, resource string, action string, logError func(context.Context, string), logWriter LogWriter) *CodeHandler {
+	return NewCodeHandler(loader, resource, action, true, logError, logWriter)
+}
+func NewCodeHandler(loader CodeLoader, resource string, action string, requiredMaster bool, logError func(context.Context, string), logWriter LogWriter) *CodeHandler {
+	if len(resource) == 0 {
+		resource = "code"
+	}
+	if len(action) == 0 {
+		action = "load"
+	}
+	h := CodeHandler{Loader: loader, Resource: resource, Action: action, RequiredMaster: requiredMaster, LogWriter: logWriter, LogError: logError}
+	return &h
+}
+func (c *CodeHandler) Load(w http.ResponseWriter, r *http.Request) {
+	code := ""
+	if c.RequiredMaster {
+		if r.Method == "GET" {
+			i := strings.LastIndex(r.RequestURI, "/")
+			if i >= 0 {
+				code = r.RequestURI[i+1:]
+			}
+		} else {
+			b, er1 := ioutil.ReadAll(r.Body)
+			if er1 != nil {
+				respondString(w, r, http.StatusBadRequest, "Body cannot is empty")
+				return
+			}
+			code = strings.Trim(string(b), " ")
+		}
+	}
+	result, er4 := c.Loader.Load(r.Context(), code)
+	if er4 != nil {
+		respondError(w, r, http.StatusInternalServerError, InternalServerError, c.LogError, c.Resource, c.Action, er4, c.LogWriter)
+	} else {
+		succeed(w, r, http.StatusOK, result, c.LogWriter, c.Resource, c.Action)
+	}
+}
+
+type LogWriter interface {
+	Write(ctx context.Context, resource string, action string, success bool, desc string) error
+}
+
+func respondString(w http.ResponseWriter, r *http.Request, code int, result string) {
+	w.WriteHeader(code)
+	w.Write([]byte(result))
+}
+func respond(w http.ResponseWriter, r *http.Request, code int, result interface{}, logWriter LogWriter, resource string, action string, success bool, desc string) {
+	response, _ := json.Marshal(result)
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(code)
+	w.Write(response)
+	if logWriter != nil {
+		logWriter.Write(r.Context(), resource, action, success, desc)
+	}
+}
+func respondError(w http.ResponseWriter, r *http.Request, code int, result interface{}, logError func(context.Context, string), resource string, action string, err error, logWriter LogWriter) {
+	if logError != nil {
+		logError(r.Context(), err.Error())
+	}
+	respond(w, r, code, result, logWriter, resource, action, false, err.Error())
+}
+func succeed(w http.ResponseWriter, r *http.Request, code int, result interface{}, logWriter LogWriter, resource string, action string) {
+	respond(w, r, code, result, logWriter, resource, action, true, "")
+}