feature (cancellation): logic to cancel request in client and server

client/helpers/ajax.js

@@ -1,4 +1,4 @@
-export function http_get(url, type = "json") {
+export function http_get(url, type = "json", params) {
     return new Promise((done, err) => {
         const xhr = new XMLHttpRequest();
         xhr.open("GET", url, true);
@@ -30,6 +30,12 @@ export function http_get(url, type = "json") {
         xhr.onerror = function() {
             handle_error_response(xhr, err);
         };
+        if (params && params.abort) {
+            params.abort.signal.onabort = () => {
+                xhr.abort();
+                handle_error_response(xhr, err);
+            };
+        }
     });
 }
 
@@ -152,10 +158,17 @@ function handle_error_response(xhr, err) {
     if (navigator.onLine === false) {
         err({ message: "Connection Lost", code: "NO_INTERNET" });
     } else if (xhr.status === 0 && xhr.responseText === "") {
+        switch(xhr.readyState) {
+        case XMLHttpRequest.DONE:
+        case XMLHttpRequest.UNSENT:
+            err({ message: "aborted", code: "ABORTED" });
+            break
+        default:
             err({
                 message: "Service unavailable, if the problem persist, contact your administrator",
                 code: "INTERNAL_SERVER_ERROR",
             });
+        }
     } else if (xhr.status === 500) {
         err({
             message: message || "Oups something went wrong with our servers",

server/common/app.go

@@ -1,8 +1,13 @@
 package common
 
+import (
+	"context"
+)
+
 type App struct {
 	Backend IBackend
 	Body    map[string]interface{}
 	Session map[string]string
 	Share   Share
+	Context context.Context
 }

server/common/types.go

@@ -46,7 +46,7 @@ type ISearch interface {
 }
 
 type IAuditPlugin interface {
-	Query(searchParams map[string]string) (AuditQueryResult, error)
+	Query(ctx *App, searchParams map[string]string) (AuditQueryResult, error)
 }
 type AuditQueryResult struct {
 	Form       *Form  `json:"form"`

server/ctrl/admin.go

@@ -147,7 +147,7 @@ func FetchAuditHandler(ctx *App, res http.ResponseWriter, req *http.Request) {
 		}
 		searchParams[key] = element[0]
 	}
-	result, err := plg.Query(searchParams)
+	result, err := plg.Query(ctx, searchParams)
 	if err != nil {
 		SendErrorResult(res, err)
 		return

server/middleware/index.go

@@ -12,13 +12,14 @@ import (
 type Middleware func(func(*App, http.ResponseWriter, *http.Request)) func(*App, http.ResponseWriter, *http.Request)
 
 func NewMiddlewareChain(fn func(*App, http.ResponseWriter, *http.Request), m []Middleware, app App) http.HandlerFunc {
+
 	return func(res http.ResponseWriter, req *http.Request) {
 		var resw ResponseWriter = NewResponseWriter(res)
 		var f func(*App, http.ResponseWriter, *http.Request) = fn
-
 		for i := len(m) - 1; i >= 0; i-- {
 			f = m[i](f)
 		}
+		app.Context = req.Context()
 		f(&app, &resw, req)
 		if req.Body != nil {
 			req.Body.Close()

server/model/audit.go

@@ -57,7 +57,7 @@ var AuditForm Form = Form{
 
 type SimpleAudit struct{}
 
-func (this SimpleAudit) Query(searchParams map[string]string) (AuditQueryResult, error) {
+func (this SimpleAudit) Query(ctx *App, searchParams map[string]string) (AuditQueryResult, error) {
 	return AuditQueryResult{
 		Form: &AuditForm,
 		RenderHTML: `<style>