Implement /edit-category

Also, /remove-from-category now accepts multiple hyphae at once, and removes them all

categories/handlers.go

@@ -16,10 +16,22 @@ func InitHandlers(r *mux.Router) {
 	r.PathPrefix("/add-to-category").HandlerFunc(handlerAddToCategory).Methods("POST")
 	r.PathPrefix("/remove-from-category").HandlerFunc(handlerRemoveFromCategory).Methods("POST")
 	r.PathPrefix("/category/").HandlerFunc(handlerCategory).Methods("GET")
+	r.PathPrefix("/edit-category/").HandlerFunc(handlerEditCategory).Methods("GET")
 	r.PathPrefix("/category").HandlerFunc(handlerListCategory).Methods("GET")
 	prepareViews()
 }
 
+func handlerEditCategory(w http.ResponseWriter, rq *http.Request) {
+	util.PrepareRq(rq)
+	catName := util.CanonicalName(strings.TrimPrefix(strings.TrimPrefix(rq.URL.Path, "/edit-category"), "/"))
+	if catName == "" {
+		http.Error(w, "No category name", http.StatusBadRequest)
+		return
+	}
+	log.Println("Editing category", catName)
+	categoryEdit(viewutil.MetaFrom(w, rq), catName)
+}
+
 func handlerListCategory(w http.ResponseWriter, rq *http.Request) {
 	log.Println("Viewing list of categories")
 	categoryList(viewutil.MetaFrom(w, rq))
@@ -36,24 +48,54 @@ func handlerCategory(w http.ResponseWriter, rq *http.Request) {
 	categoryPage(viewutil.MetaFrom(w, rq), catName)
 }
 
+// A request for removal of hyphae can either remove one hypha (used in the card on /hypha) or many hyphae (used in /edit-category). Both approaches are handled by /remove-from-category. This function finds all passed hyphae.
+//
+// There is one hypha from the hypha field. Then there are n hyphae in fields prefixed by _. It seems like I have to do it myself. Compare with PHP which handles it for you. I hope I am doing this wrong.
+func hyphaeFromRequest(rq *http.Request) (canonicalNames []string) {
+	if err := rq.ParseForm(); err != nil {
+		log.Println(err)
+	}
+	if hyphaName := util.CanonicalName(rq.PostFormValue("hypha")); hyphaName != "" {
+		canonicalNames = append(canonicalNames, hyphaName)
+	}
+	// According to https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/checkbox,
+	//
+	// > If a checkbox is unchecked when its form is submitted, there is no value submitted to the server to represent its unchecked state
+	//
+	// It means, that if there is a value, it is checked. And we can ignore values altogether.
+	for key, _ := range rq.PostForm {
+		// No prefix or "_":
+		if !strings.HasPrefix(key, "_") || len(key) == 1 {
+			continue
+		}
+		canonicalNames = append(canonicalNames, util.CanonicalName(key[1:]))
+	}
+	return
+}
+
 func handlerRemoveFromCategory(w http.ResponseWriter, rq *http.Request) {
 	util.PrepareRq(rq)
 	var (
-		hyphaName  = util.CanonicalName(rq.PostFormValue("hypha"))
+		u          = user.FromRequest(rq)
+		hyphaNames = hyphaeFromRequest(rq)
 		catName    = util.CanonicalName(rq.PostFormValue("cat"))
 		redirectTo = rq.PostFormValue("redirect-to")
 	)
-	if !user.FromRequest(rq).CanProceed("remove-from-category") {
+	if !u.CanProceed("remove-from-category") {
 		w.WriteHeader(http.StatusForbidden)
 		_, _ = io.WriteString(w, "403 Forbidden")
 		return
 	}
-	if hyphaName == "" || catName == "" {
+	if len(hyphaNames) == 0 || catName == "" {
+		log.Printf("%s passed no data for removal of hyphae from a category\n", u.Name)
 		http.Redirect(w, rq, redirectTo, http.StatusSeeOther)
 		return
 	}
-	log.Println(user.FromRequest(rq).Name, "removed", hyphaName, "from", catName)
-	removeHyphaFromCategory(hyphaName, catName)
+	for _, hyphaName := range hyphaNames {
+		// TODO: Make it more effective.
+		removeHyphaFromCategory(hyphaName, catName)
+	}
+	log.Printf("%s removed %q from category %s\n", u.Name, hyphaNames, catName)
 	http.Redirect(w, rq, redirectTo, http.StatusSeeOther)
 }
 

categories/view_edit.html

@@ -0,0 +1,35 @@
+{{define "edit category x"}}Edit category {{beautifulName .}}{{end}}
+{{define "title"}}{{template "edit category x" .CatName}}{{end}}
+{{define "body"}}
+	<main class="main-width category">
+		<h1>{{block "edit category heading" .CatName}}Edit category <a href="/category/{{.}}">{{beautifulName .}}</a>{{end}}</h1>
+	    {{if len .Hyphae | not}}
+		    <p>{{block "empty cat" .}}This category is empty{{end}}</p>
+	    {{end}}
+
+		{{if .GivenPermissionToModify}}
+			<h2>{{block "add hypha" .}}Add a hypha to the category{{end}}</h2>
+			<form method="POST" action="/add-to-category" class="category__add-form">
+				<input type="text" name="hypha" id="_hypha-name"
+				       placeholder="{{block `hypha name` .}}Hypha name{{end}}">
+				<input type="hidden" name="cat" value="{{.CatName}}">
+				<input type="hidden" name="redirect-to" value="/category/{{.CatName}}">
+				<input type="submit" class="btn" value="{{block `add` .}}Add{{end}}">
+			</form>
+
+		{{if len .Hyphae}}
+			<h2>{{block "remove hyphae" .}}Remove hyphae from the category{{end}}</h2>
+			<form method="POST" action="/remove-from-category" class="multi-remove-from-category">
+				{{range .Hyphae}}
+					<input type="checkbox" name="_{{.}}" id="_{{.}}">
+					<label for="_{{.}}"><a href="/hypha/{{.}}">{{beautifulName .}}</a></label>
+					<br>
+				{{end}}
+				<input type="hidden" name="cat" value="{{.CatName}}">
+				<input type="hidden" name="redirect-to" value="/edit-category/{{.CatName}}">
+				<input type="submit" class="btn" value="{{block `remove` .}}Remove{{end}}">
+			</form>
+		{{end}}
+		{{end}}
+	</main>
+{{end}}

categories/view_page.html

@@ -3,6 +3,11 @@
 {{define "body"}}
     {{$catName := .CatName}}
 	<main class="main-width category">
+		{{if .GivenPermissionToModify}}
+			<div class="btn btn_navititle">
+				<a class="btn__link_navititle" href="/edit-category/{{$catName}}">{{block "edit" .}}Edit{{end}}</a>
+			</div>
+		{{end}}
 		<h1>{{block "cat" .}}Category{{end}} <i>{{beautifulName $catName}}</i></h1>
         {{if len .Hyphae | not}}
 			<p>{{block "empty cat" .}}This category is empty{{end}}</p>

categories/views.go

@@ -24,14 +24,15 @@ const ruTranslation = `
 
 var (
 	//go:embed *.html
-	fs                                          embed.FS
-	viewListChain, viewPageChain, viewCardChain viewutil.Chain
+	fs                                                         embed.FS
+	viewListChain, viewPageChain, viewCardChain, viewEditChain viewutil.Chain
 )
 
 func prepareViews() {
 	viewCardChain = viewutil.CopyEnRuWith(fs, "view_card.html", ruTranslation)
 	viewListChain = viewutil.CopyEnRuWith(fs, "view_list.html", ruTranslation)
 	viewPageChain = viewutil.CopyEnRuWith(fs, "view_page.html", ruTranslation)
+	viewEditChain = viewutil.CopyEnRuWith(fs, "view_edit.html", ruTranslation)
 }
 
 type cardData struct {
@@ -54,15 +55,26 @@ func CategoryCard(meta viewutil.Meta, hyphaName string) string {
 	return buf.String()
 }
 
-type pageData struct {
+type catData struct {
 	*viewutil.BaseData
 	CatName                 string
 	Hyphae                  []string
 	GivenPermissionToModify bool
 }
 
+func categoryEdit(meta viewutil.Meta, catName string) {
+	viewutil.ExecutePage(meta, viewEditChain, catData{
+		BaseData: &viewutil.BaseData{
+			Addr: "/edit-category/" + catName,
+		},
+		CatName:                 catName,
+		Hyphae:                  hyphaeInCategory(catName),
+		GivenPermissionToModify: meta.U.CanProceed("add-to-category"),
+	})
+}
+
 func categoryPage(meta viewutil.Meta, catName string) {
-	viewutil.ExecutePage(meta, viewPageChain, pageData{
+	viewutil.ExecutePage(meta, viewPageChain, catData{
 		BaseData: &viewutil.BaseData{
 			Addr: "/category/" + catName,
 		},

user/user.go

@@ -35,8 +35,8 @@ var minimalRights = map[string]int{
 	"edit":                 1,
 	"upload-binary":        1,
 	"upload-text":          1,
-	"add-to-category":      1,
-	"remove-from-category": 1,
+	"add-to-category":      2,
+	"remove-from-category": 2,
 	"rename":               2,
 	"remove-media":         2,
 	"update-header-links":  3,