Server-Side Scripting/Iteration/Go
lesson4.go
edit// Demonstrates conditions, while loops and for loops using
// Celsius and Fahrenheit temperature conversion tables.
//
// References:
// https://www.mathsisfun.com/temperature-conversion.html
// https://golang.org/doc/
// https://golangcode.com/get-a-url-parameter-from-a-request/
// https://gowebexamples.com/
// https://tour.golang.org/
// https://pkg.go.dev/html/template
package routes
import (
"net/http"
"html/template"
"path/filepath"
"strconv"
)
func Lesson4(response http.ResponseWriter, request *http.Request) {
response.Header().Set("Content-Type", "text/html; charset=utf-8")
type Data struct {
Table template.HTML
}
result := ""
switch request.Method {
case "GET":
result = ""
case "POST":
start, _ := strconv.Atoi(request.FormValue("start"))
stop, _ := strconv.Atoi(request.FormValue("stop"))
increment, _ := strconv.Atoi(request.FormValue("increment"))
submit := request.FormValue("submit")
if submit == "Celsius" {
result = processCelsius(start, stop, increment)
} else if submit == "Fahrenheit" {
result = processFahrenheit(start, stop, increment)
} else {
result = "Unexpected submit value: " + submit
}
default:
result = "Unexpected request method: " + request.Method
}
data := Data{template.HTML(result)}
path := filepath.Join("templates", "lesson4.html")
parsed, _ := template.ParseFiles(path)
parsed.Execute(response, data)
}
func processCelsius(start int, stop int, increment int) string {
result := "<h1>Temperature Conversion</h1>"
result = result + "<table><tr><th>Celsius</th><th>Fahrenheit</th></tr>"
celsius := start
for celsius <= stop {
fahrenheit := float64(celsius) * 9 / 5 + 32
result += "<tr><td>" + strconv.Itoa(celsius) + "</td>"
result += "<td>" + strconv.FormatFloat(fahrenheit, 'f', 1, 64) + "</td></tr>"
celsius += increment
}
result += "</table>"
return result
}
func processFahrenheit(start int, stop int, increment int) string {
result := "<h1>Temperature Conversion</h1>"
result = result + "<table><tr><th>Fahrenheit</th><th>Celsius</th></tr>"
for fahrenheit := start; fahrenheit <= stop; fahrenheit += increment {
temp := float64(fahrenheit)
celsius := (float64(temp) - 32) * 5 / 9
result += "<tr><td>" + strconv.Itoa(fahrenheit) + "</td>"
result += "<td>" + strconv.FormatFloat(celsius, 'f', 1, 64) + "</td></tr>"
}
result += "</table>"
return result
}
lesson4.html
edit<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Lesson 4</title>
<link rel="stylesheet" href="styles.css">
<style>
p {
min-height: 1em;
}
</style>
</head>
<body>
<h1>Temperature Conversion</h1>
<form method="POST">
<p><label for="start">Start:</label>
<input type="text" id="start" name="start" value="0">
</p>
<p><label for="stop">Stop:</label>
<input type="text" id="stop" name="stop" value="100">
</p>
<p><label for="increment:">Increment</label>
<input type="text" id="increment" name="increment" value="10">
</p>
<p><input type="submit" name="submit" value="Celsius">
<input type="submit" name="submit" value="Fahrenheit">
</p>
</form>
{{.Table}}
</body>
</html>
Try It
editSee Server-Side Scripting/Routes and Templates/Go to create a test environment.