138 lines
4.0 KiB

package util
import (
// PrepareRq strips the trailing / in rq.URL.Path. In the future it might do more stuff for making all request structs uniform.
func PrepareRq(rq *http.Request) {
rq.URL.Path = strings.TrimSuffix(rq.URL.Path, "/")
// ShorterPath is used by handlerList to display shorter path to the files. It
// simply strips the hyphae directory name.
func ShorterPath(path string) string {
if strings.HasPrefix(path, files.HyphaeDir()) {
tmp := strings.TrimPrefix(path, files.HyphaeDir())
if tmp == "" {
return ""
return tmp[1:]
return path
// HTTP404Page writes a 404 error in the status, needed when no content is found on the page.
func HTTP404Page(w http.ResponseWriter, page string) {
w.Header().Set("Content-Type", "text/html;charset=utf-8")
_, _ = w.Write([]byte(page))
// HTTP200Page wraps some frequently used things for successful 200 responses.
func HTTP200Page(w http.ResponseWriter, page string) {
w.Header().Set("Content-Type", "text/html;charset=utf-8")
_, _ = w.Write([]byte(page))
// RandomString generates a random string of the given length. It is cryptographically secure to some extent.
func RandomString(n int) (string, error) {
bytes := make([]byte, n)
if _, err := rand.Read(bytes); err != nil {
return "", err
return hex.EncodeToString(bytes), nil
// BeautifulName makes the ugly name beautiful by replacing _ with spaces and using title case.
func BeautifulName(uglyName string) string {
// Why not reuse
return util.BeautifulName(uglyName)
// CanonicalName makes sure the `name` is canonical. A name is canonical if it is lowercase and all spaces are replaced with underscores.
func CanonicalName(name string) string {
return util.CanonicalName(name)
// IsProfileName if the given hypha name is a profile name. It takes configuration into consideration.
// With default configuration, u/ is the prefix such names have. For example, u/wikimind matches. Note that u/wikimind/sub does not.
func IsProfileName(hyphaName string) bool {
return strings.HasPrefix(hyphaName, cfg.UserHypha+"/") && strings.Count(hyphaName, "/") == 1
// HyphaNameFromRq extracts hypha name from http request. You have to also pass the action which is embedded in the url or several actions. For url /hypha/hypha, the action would be "hypha".
func HyphaNameFromRq(rq *http.Request, actions ...string) string {
p := rq.URL.Path
for _, action := range actions {
if strings.HasPrefix(p, "/"+action+"/") {
return CanonicalName(strings.TrimPrefix(p, "/"+action+"/"))
log.Println("HyphaNameFromRq: this request is invalid, fall back to home hypha")
return cfg.HomeHypha
// FormData is a convenient struct for passing user input and errors to HTML
// forms and showing to the user.
type FormData struct {
err error
fields map[string]string
// NewFormData constructs empty form data instance.
func NewFormData() FormData {
return FormData{
err: nil,
fields: map[string]string{},
// FormDataFromRequest extracts a form data from request, using a set of keys.
func FormDataFromRequest(r *http.Request, keys []string) FormData {
formData := NewFormData()
for _, key := range keys {
formData.Put(key, r.FormValue(key))
return formData
// HasError is true if there is indeed an error.
func (f FormData) HasError() bool {
return f.err != nil
// Error returns an error text or empty string, if there are no errors in form data.
func (f FormData) Error() string {
if f.err == nil {
return ""
return f.err.Error()
// WithError puts an error into form data and returns itself.
func (f FormData) WithError(err error) FormData {
f.err = err
return f
// Get accesses form data with a key
func (f FormData) Get(key string) string {
return f.fields[key]
// Put writes a form value for provided key
func (f FormData) Put(key, value string) {
f.fields[key] = value