Added a basic webserver with view, save, edit functionality as a part of the go learning course to view and edit files

Author: anarchymonkey

create_a_webserver/go.work

@@ -0,0 +1,6 @@
+go 1.20
+
+use (
+	./webserver
+	./wiki
+)

create_a_webserver/webserver/anikets_file.txt

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+            This is my own file, what are you gonna do man
+        

create_a_webserver/webserver/go.mod

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+module aniketbatabyal.com/webserver
+
+go 1.20
+
+replace batsy.com/wiki => ../wiki
+
+require batsy.com/wiki v0.0.0-00010101000000-000000000000

create_a_webserver/webserver/public/template.html

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+<h1>Editing {{.Title}}</h1>
+
+<form action="/save/{{.Title}}" method="POST">
+    <div>
+        <textarea name="body" rows="20" cols="80">
+            {{printf "%s" .Body}}
+        </textarea>
+    </div>
+    <div>
+        <input type="submit" value="Save">
+    </div>
+</form>

create_a_webserver/webserver/public/view.html

@@ -0,0 +1,9 @@
+<h1>Viewing {{ .Title }}</h1>
+
+<div>
+    [<a href="/edit/">edit</a>]
+</div>
+<p>
+    The body is 
+    {{ printf "%s" .Body }}
+</p>

create_a_webserver/webserver/webserver.go

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+package main
+
+import (
+	"fmt"
+	"html/template"
+	"log"
+	"net/http"
+
+	"batsy.com/wiki"
+)
+
+func handlerFunc(w http.ResponseWriter, req *http.Request) {
+	w.Header().Add("Content-Type", "text/html")
+	fmt.Fprintf(w, "This is so awesome %s", req.URL.Path[1:])
+}
+
+// remove duplicacy
+
+func renderTemplate(htmlFileLocation string, writer http.ResponseWriter, page *wiki.Page) {
+	respTemplate, err := template.ParseFiles(htmlFileLocation)
+
+	if err != nil {
+		log.Fatal("Something went wrong", err)
+	}
+
+	respTemplate.Execute(writer, page)
+}
+
+func viewHandler(w http.ResponseWriter, req *http.Request) {
+	title := req.URL.Path[len("/view/"):]
+
+	p, err := wiki.LoadPage(title)
+
+	if err != nil {
+		http.Redirect(w, req, "/edit/"+title, http.StatusFound)
+		return
+	}
+
+	renderTemplate("./public/view.html", w, p)
+}
+
+func editHandler(w http.ResponseWriter, req *http.Request) {
+	title := req.URL.Path[len("/edit/"):]
+
+	page, err := wiki.LoadPage(title)
+
+	if err != nil {
+		page = &wiki.Page{Title: "Tempfile"}
+	}
+
+	renderTemplate("./public/template.html", w, page)
+}
+
+func saveHandler(w http.ResponseWriter, req *http.Request) {
+	title := req.URL.Path[len("/save/"):]
+	body := req.FormValue("body")
+
+	page := &wiki.Page{Title: title, Body: []byte(body)}
+	page.Save()
+
+	http.Redirect(w, req, "/view/"+title, http.StatusFound)
+}
+
+func main() {
+
+	http.HandleFunc("/", handlerFunc)
+	http.HandleFunc("/view/", viewHandler)
+	http.HandleFunc("/edit/", editHandler)
+	http.HandleFunc("/save/", saveHandler)
+
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}

create_a_webserver/wiki/go.mod

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+module batsy.com/wiki
+
+go 1.20

create_a_webserver/wiki/wiki.go

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+package wiki
+
+import (
+	"fmt"
+	"os"
+)
+
+type Page struct {
+	Title string
+	Body  []byte
+}
+
+const EXTENTION = "txt"
+
+// This is a method named save that takes as its receiver p, a pointer to Page . It takes no parameters, and returns a value of type error.
+func (p *Page) Save() error {
+	fileName := fmt.Sprintf("%s.%s", p.Title, EXTENTION)
+
+	// 0600 means read write permissions
+	return os.WriteFile(fileName, p.Body, 0600)
+}
+
+func LoadPage(title string) (*Page, error) {
+	fileName := fmt.Sprintf("%s.%s", title, EXTENTION)
+	body, error := os.ReadFile(fileName)
+
+	if error != nil {
+		return nil, error
+	}
+	return &Page{Title: title, Body: body}, nil
+}