add delete post functionality

database/database.go

@@ -162,9 +162,11 @@ func (d DB) CreateThread(title, content string, authorid, topicid int) (int, err
 // https://medium.com/aubergine-solutions/how-i-handled-null-possible-values-from-database-rows-in-golang-521fb0ee267
 // type NullTime sql.NullTime
 type Post struct {
+	ID          int
 	ThreadTitle string
 	Content     template.HTML
 	Author      string
+	AuthorID    int
 	Publish     time.Time
 	LastEdit    sql.NullTime // TODO: handle json marshalling with custom type
 }
@@ -182,7 +184,7 @@ func (d DB) GetThread(threadid int) []Post {
 	//    users table to get user name
 	//    threads table to get thread title
 	query := `
-  SELECT t.title, content, u.name, p.publishtime, p.lastedit
+  SELECT p.id, t.title, content, u.name, p.authorid, p.publishtime, p.lastedit
   FROM posts p 
   INNER JOIN users u ON u.id = p.authorid 
   INNER JOIN threads t ON t.id = p.threadid
@@ -200,14 +202,28 @@ func (d DB) GetThread(threadid int) []Post {
 	var data Post
 	var posts []Post
 	for rows.Next() {
-		if err := rows.Scan(&data.ThreadTitle, &data.Content, &data.Author, &data.Publish, &data.LastEdit); err != nil {
+		if err := rows.Scan(&data.ID, &data.ThreadTitle, &data.Content, &data.Author, &data.AuthorID, &data.Publish, &data.LastEdit); err != nil {
 			log.Fatalln(util.Eout(err, "get data for thread %d", threadid))
 		}
 		posts = append(posts, data)
 	}
 	return posts
 }
 
+func (d DB) GetPost(postid int) (Post, error) {
+	stmt := `
+  SELECT p.id, t.title, content, u.name, p.authorid, p.publishtime, p.lastedit
+  FROM posts p 
+  INNER JOIN users u ON u.id = p.authorid 
+  INNER JOIN threads t ON t.id = p.threadid
+  WHERE p.id = ?
+  `
+	var data Post
+	err := d.db.QueryRow(stmt, postid).Scan(&data.ID, &data.ThreadTitle, &data.Content, &data.Author, &data.AuthorID, &data.Publish, &data.LastEdit)
+	err = util.Eout(err, "get data for thread %d", postid)
+	return data, err
+}
+
 type Thread struct {
 	Title   string
 	Author  string
@@ -257,10 +273,10 @@ func (d DB) EditPost(content string, postid int) {
 	util.Check(err, "edit post %d", postid)
 }
 
-func (d DB) DeletePost(postid int) {
+func (d DB) DeletePost(postid int) error {
 	stmt := `DELETE FROM posts WHERE id = ?`
 	_, err := d.Exec(stmt, postid)
-	util.Check(err, "deleting post %d", postid)
+	return util.Eout(err, "deleting post %d", postid)
 }
 
 func (d DB) CreateTopic(title, description string) {

html/thread.html

@@ -1,10 +1,28 @@
 {{ template "head" . }}
 <main>
     <h1>{{ .Data.Title }}</h1>
+    {{ $userID := .LoggedInID }}
+    {{ $threadURL := .Data.ThreadURL }}
     {{ range $index, $post := .Data.Posts }}
     <article>
         <div>
-            <p><span><b>{{ $post.Author }}</b><span class="visually-hidden"> responded:</span></span><span style="float: right;"><time datetime="{{ $post.Publish | formatDate }}">{{ $post.Publish | formatDateRelative }}</time></span></p>
+            {{ if eq $post.AuthorID $userID }} 
+                <span style="float: right;" aria-label="Delete this post">
+                    <form style="display: inline-block;" method="POST" action="/post/delete/{{ $post.ID }}"
+                            onsubmit="return confirm('Delete post for all posterity?');"
+                        >
+                        <button style="background-color: transparent; border: 0; padding: 0;" type="submit">delete</button>
+                        <input type="hidden" name="thread" value="{{ $threadURL }}">
+                    </form>
+                </span>
+            {{ end }}
+            <p>
+            <span><b>{{ $post.Author }}</b>
+                <span class="visually-hidden"> responded:</span></span>
+            <span style="margin-left: 0.5rem; font-style: italic;">
+                <time datetime="{{ $post.Publish | formatDate }}">{{ $post.Publish | formatDateRelative }}</time>
+            </span>
+            </p>
             {{ $post.Content }}
     </article>
     {{ end }}

server/server.go

@@ -7,7 +7,6 @@ import (
 	"html/template"
 	"net/http"
 	"net/url"
-	"strconv"
 	"strings"
 	"time"
 
@@ -23,9 +22,10 @@ import (
 /* TODO (2022-01-03): include csrf token via gorilla, or w/e, when rendering */
 
 type TemplateData struct {
-	Data     interface{}
-	LoggedIn bool // TODO (2022-01-09): put this in a middleware || template function or sth?
-	Title    string
+	Data       interface{}
+	LoggedIn   bool // TODO (2022-01-09): put this in a middleware || template function or sth?
+	LoggedInID int
+	Title      string
 }
 
 type IndexData struct {
@@ -54,8 +54,9 @@ type LoginData struct {
 }
 
 type ThreadData struct {
-	Title string
-	Posts []database.Post
+	Title     string
+	Posts     []database.Post
+	ThreadURL string
 }
 
 type RequestHandler struct {
@@ -159,21 +160,14 @@ func (h RequestHandler) renderView(res http.ResponseWriter, viewName string, dat
 }
 
 func (h RequestHandler) ThreadRoute(res http.ResponseWriter, req *http.Request) {
-	parts := strings.Split(strings.TrimSpace(req.URL.Path), "/")
-	// invalid route, redirect to index
-	if len(parts) < 2 || parts[2] == "" {
-		IndexRedirect(res, req)
-		return
-	}
+	threadid, ok := util.GetURLPortion(req, 2)
 	loggedIn, userid := h.IsLoggedIn(req)
 
-	threadid, err := strconv.Atoi(parts[2])
-	if err != nil {
-		dump(err)
-		title := "Page not found"
+	if !ok {
+		title := "Thread not found"
 		data := GenericMessageData{
 			Title:   title,
-			Message: "The visited page does not exist (anymore?)",
+			Message: "The thread does not exist (anymore?)",
 		}
 		h.renderView(res, "generic-message", TemplateData{Data: data, LoggedIn: loggedIn})
 		return
@@ -197,7 +191,7 @@ func (h RequestHandler) ThreadRoute(res http.ResponseWriter, req *http.Request)
 		thread[i].Content = util.Markup(post.Content)
 	}
 	title := thread[0].ThreadTitle
-	view := TemplateData{ThreadData{title, thread}, loggedIn, title}
+	view := TemplateData{Data: ThreadData{title, thread, req.URL.Path}, LoggedIn: loggedIn, LoggedInID: userid, Title: title}
 	h.renderView(res, "thread", view)
 }
 
@@ -219,7 +213,7 @@ func (h RequestHandler) IndexRoute(res http.ResponseWriter, req *http.Request) {
 	loggedIn, _ := h.IsLoggedIn(req)
 	// show index listing
 	threads := h.db.ListThreads()
-	view := TemplateData{IndexData{threads}, loggedIn, "threads"}
+	view := TemplateData{Data: IndexData{threads}, LoggedIn: loggedIn, Title: "threads"}
 	h.renderView(res, "index", view)
 }
 
@@ -240,7 +234,7 @@ func (h RequestHandler) LoginRoute(res http.ResponseWriter, req *http.Request) {
 	loggedIn, _ := h.IsLoggedIn(req)
 	switch req.Method {
 	case "GET":
-		h.renderView(res, "login", TemplateData{LoginData{}, loggedIn, ""})
+		h.renderView(res, "login", TemplateData{Data: LoginData{}, LoggedIn: loggedIn, Title: ""})
 	case "POST":
 		username := req.PostFormValue("username")
 		password := req.PostFormValue("password")
@@ -252,7 +246,7 @@ func (h RequestHandler) LoginRoute(res http.ResponseWriter, req *http.Request) {
 		}
 		if err != nil {
 			fmt.Println(err)
-			h.renderView(res, "login", TemplateData{LoginData{FailedAttempt: true}, loggedIn, ""})
+			h.renderView(res, "login", TemplateData{Data: LoginData{FailedAttempt: true}, LoggedIn: loggedIn, Title: ""})
 			return
 		}
 		// save user id in cookie
@@ -291,7 +285,7 @@ func (h RequestHandler) RegisterRoute(res http.ResponseWriter, req *http.Request
 			LinkMessage: "Visit the",
 			LinkText:    "index",
 		}
-		h.renderView(res, "generic-message", TemplateData{data, loggedIn, "register"})
+		h.renderView(res, "generic-message", TemplateData{Data: data, LoggedIn: loggedIn, Title: "register"})
 		return
 	}
 
@@ -383,7 +377,7 @@ func (h RequestHandler) RegisterRoute(res http.ResponseWriter, req *http.Request
 		ed.Check(err, "generate keypair")
 		kpJson, err := keypair.Marshal()
 		ed.Check(err, "marshal keypair")
-		h.renderView(res, "register-success", TemplateData{RegisterSuccessData{string(kpJson)}, loggedIn, "registered successfully"})
+		h.renderView(res, "register-success", TemplateData{Data: RegisterSuccessData{string(kpJson)}, LoggedIn: loggedIn, Title: "registered successfully"})
 	default:
 		fmt.Println("non get/post method, redirecting to index")
 		IndexRedirect(res, req)
@@ -452,6 +446,59 @@ func (h RequestHandler) NewThreadRoute(res http.ResponseWriter, req *http.Reques
 	}
 }
 
+func (h RequestHandler) DeletePostRoute(res http.ResponseWriter, req *http.Request) {
+	if req.Method == "GET" {
+		IndexRedirect(res, req)
+		return
+	}
+	threadURL := req.PostFormValue("thread")
+	postid, ok := util.GetURLPortion(req, 3)
+	loggedIn, userid := h.IsLoggedIn(req)
+
+	// generic error message base, with specifics being swapped out depending on the error
+	genericErr := GenericMessageData{
+		Title:       "Unaccepted request",
+		LinkMessage: "Go back to",
+		Link:        threadURL,
+		LinkText:    "the thread",
+	}
+
+	renderErr := func(msg string) {
+		fmt.Println(msg)
+		genericErr.Message = msg
+		h.renderView(res, "generic-message", TemplateData{Data: genericErr, LoggedIn: loggedIn})
+	}
+
+	if !loggedIn || !ok {
+		renderErr("Invalid post id, or you were not allowed to delete it")
+		return
+	}
+
+	post, err := h.db.GetPost(postid)
+	if err != nil {
+		dump(err)
+		renderErr("The post you tried to delete was not found")
+		return
+	}
+
+	authorized := post.AuthorID == userid
+	switch req.Method {
+	case "POST":
+		if authorized {
+			err = h.db.DeletePost(postid)
+			if err != nil {
+				dump(err)
+				renderErr("Error happened while deleting the post")
+				return
+			}
+		} else {
+			renderErr("That's not your post to delete? Sorry buddy!")
+			return
+		}
+	}
+	http.Redirect(res, req, threadURL, http.StatusSeeOther)
+}
+
 func Serve(allowlist []string, sessionKey string, isdev bool) {
 	port := ":8272"
 	dbpath := "./data/forum.db"
@@ -469,6 +516,7 @@ func Serve(allowlist []string, sessionKey string, isdev bool) {
 	http.HandleFunc("/logout", handler.LogoutRoute)
 	http.HandleFunc("/login", handler.LoginRoute)
 	http.HandleFunc("/register", handler.RegisterRoute)
+	http.HandleFunc("/post/delete/", handler.DeletePostRoute)
 	http.HandleFunc("/thread/new/", handler.NewThreadRoute)
 	http.HandleFunc("/thread/", handler.ThreadRoute)
 	http.HandleFunc("/robots.txt", handler.RobotsRoute)

util/util.go

@@ -4,7 +4,9 @@ import (
 	"fmt"
 	"html/template"
 	"log"
+	"net/http"
 	"net/url"
+	"strconv"
 	"strings"
 
 	"github.com/gomarkdown/markdown"
@@ -98,3 +100,18 @@ func SanitizeURL(input string) string {
 	// TODO(2022-01-08): evaluate use of strict content guardian?
 	return strings.ToLower(input)
 }
+
+// returns an id from a url path, and a boolean. the boolean is true if we're returning what we expect; false if the
+// operation failed
+func GetURLPortion(req *http.Request, index int) (int, bool) {
+	var desiredID int
+	parts := strings.Split(strings.TrimSpace(req.URL.Path), "/")
+	if len(parts) < index || parts[index] == "" {
+		return -1, false
+	}
+	desiredID, err := strconv.Atoi(parts[index])
+	if err != nil {
+		return -1, false
+	}
+	return desiredID, true
+}