basic common app packages

response/reply.go

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+// Copyright 2024 Patial Tech (Ankit Patial).
+// All rights reserved.
+
+package response
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"code.patial.tech/go/appcore/request"
+)
+
+// Detail of api response
+type Detail struct {
+	// Data of api response
+	//
+	// it will nil in case of error
+	Data any `json:"data"`
+
+	// Error if any occurred during api call
+	Error *string `json:"error,omitempty"`
+
+	// Pager is used for paged data response
+	Pager *request.Pager `json:"pager,omitempty"`
+}
+
+// Done data response
+func Ok(w http.ResponseWriter, data any) {
+	reply(w, data, nil)
+}
+
+// Paged data response
+func Paged(w http.ResponseWriter, data any, p request.Pager) {
+	reply(w, data, &p)
+}
+
+func reply(w http.ResponseWriter, data any, p *request.Pager) {
+	w.Header().Set("Content-Type", "application/json")
+	// Requires the client to validate the response with the server before using the cached version,
+	// ensuring data freshness.
+	w.Header().Set("Cache-Control", "no-cache")
+	// older HTTP header used for controlling caching behavior in HTTP/1.0,
+	// primarily for backwards compatibility with older browsers and caches
+	w.Header().Set("Pragma", "no-cache")
+
+	// if data is nil, let's pass it on as null
+	if data == nil {
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte("{\"data\":null}"))
+		return
+	}
+
+	// json data...
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(Detail{
+		Data:  data,
+		Pager: p,
+	})
+}
+
+func BadRequest(w http.ResponseWriter, err error) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusBadRequest)
+	w.Write(fmt.Appendf(nil, "{\"error\": %q}", err.Error()))
+}
+
+func InternalServerError(w http.ResponseWriter, err error) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusInternalServerError)
+	w.Write(fmt.Appendf(nil, "{\"error\": %q}", err.Error()))
+}
+
+func SessionExpired(w http.ResponseWriter) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusUnauthorized)
+	w.Write([]byte("{\"error\": \"Session is expired, please login again\"}"))
+}
+
+func NotAutorized(w http.ResponseWriter) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusBadRequest)
+	w.Write([]byte("{\"error\": \"You are not authorized to perform this action\"}"))
+}
+
+// Forbidden response error
+func Forbidden(w http.ResponseWriter, err error) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusForbidden)
+	w.Write(fmt.Appendf(nil, "{\"error\": %q}", err.Error()))
+}