My goal is:
<a href> to enable/disable a functionTwo first points are OK (or feel free to tell me what I may improve)
But I have no idea how to do the third point (because way I used for first points is not good?)
package main
import (
"html/template"
"github.com/labstack/echo"
"log"
"io"
"net/http"
"strconv"
"fmt"
"time"
)
//init LOG
func init(){
log.SetPrefix("TRACE: ")
log.SetFlags(log.Ldate | log.Ltime | log.Llongfile)
log.Println("init started")
}
// main function
func main() {
// defining struct instance
settings.Enabled = false
// Parsing the required html
// file in same directory
// Parsing Templates
t := &Template{
templates: template.Must(template.ParseGlob("test.html")),
}
// standard output to print merged data
e := echo.New()
e.Renderer = t
e.HideBanner = false
e.HidePort = false
e.Debug = true
e.GET("/", index)
e.GET("/toggleEnable", toggleEnable)
e.Start("127.0.0.1" + ":" + strconv.Itoa(8080))
}
func index(c echo.Context) error {
return c.Render(http.StatusOK, "index", settings)
}
// Settings Type ...
type Settings struct {
Enabled bool
}
var settings Settings
type Template struct {
templates *template.Template
}
func (t *Template) Render(w io.Writer, name string, data interface{}, c echo.Context) error {
return t.templates.ExecuteTemplate(w, name, data)
}
func toggleEnable(c echo.Context) error {
if settings.Enabled {
settings.Enabled = false
} else {
settings.Enabled = true
Sum()
}
return c.Redirect(http.StatusTemporaryRedirect, c.Request().Header.Get("Referer"))
}
func Sum() {
sum := 0
for i := 1; i < 50; i++ {
sum += i
fmt.Println(sum)
time.Sleep(3 * time.Second)
}
}
and test.html:
```
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
</head>
<body>
{{define "index"}}
<h1>Settings</h1>
<p>Test enabled : <a href="/toggleEnable">{{.Enabled }}</a></p>
{{end}}
</body>
</html>
```
For the moment, if I false -> true: sum works and if I true-> false: nothing happens and if I false -> true one more time: an other count begin.
Next step will be to display count in html page.
As currently written when the browser requests /toggleEnable nothing will be returned until Sum() completes (which will take around 150 seconds). After the Sum() is complete the page with Test enabled : false will be returned/displayed. If you want to provide the ability for the user to interrupt the process then it's probably best to run it in a Goroutine; something like this:
// Settings Type ...
type Settings struct {
Enabled bool
Stop chan struct{}
}
var settings Settings
type Template struct {
templates *template.Template
}
func (t *Template) Render(w io.Writer, name string, data interface{}, c echo.Context) error {
return t.templates.ExecuteTemplate(w, name, data)
}
func toggleEnable(c echo.Context) error {
if settings.Enabled {
settings.Enabled = false
close(settings.Stop)
} else {
settings.Enabled = true
settings.Stop = make(chan struct{})
go Sum(settings.Stop)
}
return c.Redirect(http.StatusTemporaryRedirect, c.Request().Header.Get("Referer"))
}
func Sum(stop chan struct{}) {
sum := 0
for i := 1; i < 50; i++ {
sum += i
fmt.Println(sum)
select {
case <-stop:
fmt.Println("stopped")
return
case <-time.After(3 * time.Second):
}
}
}
Note that there are some issues with this. It is written on the assumption that there will be a single client and the page will not be updated when the timer completes (you would need to add a refresh or similar).
Next step will be to display count in html page
To do this you will need a way for the browser to request updates. This could be through a refresh (fairly simple but not a great user experience) or using Javascript (either polling or using websockets).