-;;; elpher.el --- A friendly gopher client.
+;;; elpher.el --- A friendly gopher client. -*- lexical-binding:t -*-
;; Copyright (C) 2019 Tim Vaughan
;; Author: Tim Vaughan <tgvaughan@gmail.com>
;; Created: 11 April 2019
-;; Version: 1.2.3
+;; Version: 2.3.5
;; Keywords: comm gopher
;; Homepage: https://github.com/tgvaughan/elpher
-;; Package-Requires: ((emacs "25"))
+;; Package-Requires: ((emacs "26"))
;; This file is not part of GNU Emacs.
;;; Commentary:
-;; Elpher aims to provide a practical gopher client for GNU Emacs.
-;; It supports:
+;; Elpher aims to provide a practical and friendly gopher client
+;; for GNU Emacs. It supports:
-;; - intuitive keyboard and mouse-driven interface,
-;; - caching of visited sites (both content and cursor position),
+;; - intuitive keyboard and mouse-driven browsing,
+;; - out-of-the-box compatibility with evil-mode,
+;; - clickable web and gopher links *in plain text*,
+;; - caching of visited sites,
;; - pleasant and configurable colouring of Gopher directories,
;; - direct visualisation of image files,
-;; - (m)enu key support, similar to Emacs' info browser,
-;; - clickable web and gopher links in plain text,
-;; - a simple bookmark management system.
-
-;; Visited pages are stored as a hierarchy rather than a linear history,
-;; meaning that navigation between these pages is quick and easy.
+;; - a simple bookmark management system,
+;; - connections using TLS encryption,
+;; - basic support for the fledgling Gemini protocol.
;; To launch Elpher, simply use 'M-x elpher'. This will open a start
;; page containing information on key bindings and suggested starting
;; points for your gopher exploration.
-;; Faces, caching and other options can be configured via
-;; the Elpher customization group in Applications.
+;; Full instructions can be found in the Elpher info manual.
+
+;; Elpher is under active development. Any suggestions for
+;; improvements are welcome!
;;; Code:
(provide 'elpher)
+
+;;; Dependencies
+;;
+
(require 'seq)
(require 'pp)
(require 'shr)
+(require 'url-util)
+(require 'subr-x)
+
;;; Global constants
;;
-(defconst elpher-version "1.2.3"
+(defconst elpher-version "2.3.5"
"Current version of elpher.")
(defconst elpher-margin-width 6
"Width of left-hand margin used when rendering indicies.")
-(defconst elpher-start-index
- (mapconcat
- 'identity
- (list "i\tfake\tfake\t1"
- "i --------------------------------------------\tfake\tfake\t1"
- "i Elpher Gopher Client \tfake\tfake\t1"
- (format "i version %s\tfake\tfake\t1" elpher-version)
- "i --------------------------------------------\tfake\tfake\t1"
- "i\tfake\tfake\t1"
- "iUsage:\tfake\tfake\t1"
- "i\tfake\tfake\t1"
- "i - tab/shift-tab: next/prev item on current page\tfake\tfake\t1"
- "i - RET/mouse-1: open item under cursor\tfake\tfake\t1"
- "i - m: select an item on current page by name (autocompletes)\tfake\tfake\t1"
- "i - u: return to parent\tfake\tfake\t1"
- "i - O: visit the root menu of the current server\tfake\tfake\t1"
- "i - g: go to a particular menu or item\tfake\tfake\t1"
- "i - i/I: info on item under cursor or current page\tfake\tfake\t1"
- "i - c/C: copy URL representation of item under cursor or current page\tfake\tfake\t1"
- "i - a/A: bookmark the item under cursor or current page\tfake\tfake\t1"
- "i - x/X: remove bookmark for item under cursor or current page\tfake\tfake\t1"
- "i - B: visit the bookmarks page\tfake\tfake\t1"
- "i - r: redraw current page (using cached contents if available)\tfake\tfake\t1"
- "i - R: reload current page (regenerates cache)\tfake\tfake\t1"
- "i - d: download directory entry under cursor\tfake\tfake\t1"
- "i - w: display the raw server response for the current page\tfake\tfake\t1"
- "i\tfake\tfake\t1"
- "iWhere to start exploring Gopherspace:\tfake\tfake\t1"
- "i\tfake\tfake\t1"
- "1Floodgap Systems Gopher Server\t/\tgopher.floodgap.com\t70"
- "i\tfake\tfake\t1"
- "iAlternatively, select the following item and enter some\tfake\tfake\t1"
- "isearch terms:\tfake\tfake\t1"
- "i\tfake\tfake\t1"
- "7Veronica-2 Gopher Search Engine\t/v2/vs\tgopher.floodgap.com\t70"
- ".\r\n")
- "\r\n")
- "Source for elpher start page.")
-
(defconst elpher-type-map
- '((?0 elpher-get-text-node "T" elpher-text)
- (?1 elpher-get-index-node "/" elpher-index)
- (?4 elpher-get-node-download "B" elpher-binary)
- (?5 elpher-get-node-download "B" elpher-binary)
- (?7 elpher-get-search-node "?" elpher-search)
- (?8 elpher-get-telnet-node "?" elpher-telnet)
- (?9 elpher-get-node-download "B" elpher-binary)
- (?g elpher-get-image-node "im" elpher-image)
- (?p elpher-get-image-node "im" elpher-image)
- (?I elpher-get-image-node "im" elpher-image)
- (?d elpher-get-node-download "d" elpher-binary)
- (?h elpher-get-url-node "W" elpher-url)
- (bookmarks elpher-get-bookmarks-node "#" elpher-index)
- (start elpher-get-start-node "#" elpher-index))
- "Association list from types to getters, margin codes and index faces.")
+ '(((gopher ?0) elpher-get-gopher-node elpher-render-text "txt" elpher-text)
+ ((gopher ?1) elpher-get-gopher-node elpher-render-index "/" elpher-index)
+ ((gopher ?4) elpher-get-gopher-node elpher-render-download "bin" elpher-binary)
+ ((gopher ?5) elpher-get-gopher-node elpher-render-download "bin" elpher-binary)
+ ((gopher ?7) elpher-get-gopher-query-node elpher-render-index "?" elpher-search)
+ ((gopher ?9) elpher-get-gopher-node elpher-render-download "bin" elpher-binary)
+ ((gopher ?g) elpher-get-gopher-node elpher-render-image "img" elpher-image)
+ ((gopher ?p) elpher-get-gopher-node elpher-render-image "img" elpher-image)
+ ((gopher ?I) elpher-get-gopher-node elpher-render-image "img" elpher-image)
+ ((gopher ?d) elpher-get-gopher-node elpher-render-download "doc" elpher-binary)
+ ((gopher ?P) elpher-get-gopher-node elpher-render-download "doc" elpher-binary)
+ ((gopher ?s) elpher-get-gopher-node elpher-render-download "snd" elpher-binary)
+ ((gopher ?h) elpher-get-gopher-node elpher-render-html "htm" elpher-html)
+ (gemini elpher-get-gemini-node elpher-render-gemini "gem" elpher-gemini)
+ (telnet elpher-get-telnet-node nil "tel" elpher-telnet)
+ (other-url elpher-get-other-url-node nil "url" elpher-other-url)
+ ((special bookmarks) elpher-get-bookmarks-node nil)
+ ((special start) elpher-get-start-node nil))
+ "Association list from types to getters, renderers, margin codes and index faces.")
;;; Customization group
'((t :inherit warning))
"Face used for search type directory records.")
-(defface elpher-url
+(defface elpher-html
+ '((t :inherit font-lock-comment-face))
+ "Face used for html type directory records.")
+
+(defface elpher-gemini
+ '((t :inherit font-lock-regexp-grouping-backslash))
+ "Face used for html type directory records.")
+
+(defface elpher-other-url
'((t :inherit font-lock-comment-face))
- "Face used for url type directory records.")
+ "Face used for other URL type links records.")
(defface elpher-telnet
'((t :inherit font-lock-function-name-face))
Otherwise, use the system browser via the BROWSE-URL function."
:type '(boolean))
-(defcustom elpher-buttonify-urls-in-directories nil
+(defcustom elpher-buttonify-urls-in-directories t
"If non-nil, turns URLs matched in directories into clickable buttons."
:type '(boolean))
-(defcustom elpher-cache-images nil
- "If non-nil, cache images in memory in the same way as other content."
- :type '(boolean))
-
(defcustom elpher-use-header t
"If non-nil, display current node information in buffer header."
:type '(boolean))
+(defcustom elpher-auto-disengage-TLS nil
+ "If non-nil, automatically disengage TLS following an unsuccessful connection.
+While enabling this may seem convenient, it is also potentially dangerous as it
+allows switching from an encrypted channel back to plain text without user input."
+ :type '(boolean))
+
+
;;; Model
;;
;; Address
-(defun elpher-make-address (type &optional selector host port)
- "Create an address of a gopher object with TYPE, SELECTOR, HOST and PORT.
-Although selector host and port are optional, they are only omitted for
-special address types, such as 'start for the start page."
- (list type selector host port))
+;; An elpher "address" object is either a url object or a symbol.
+;; Symbol addresses are "special", corresponding to pages generated
+;; dynamically for and by elpher. All others represent pages which
+;; rely on content retrieved over the network.
+
+(defun elpher-address-from-url (url-string)
+ "Create a ADDRESS object corresponding to the given URL-STRING."
+ (let ((data (match-data))) ; Prevent parsing clobbering match data
+ (unwind-protect
+ (let ((url (url-generic-parse-url url-string)))
+ (unless (and (not (url-fullness url)) (url-type url))
+ (setf (url-fullness url) t)
+ (setf (url-filename url)
+ (url-unhex-string (url-filename url)))
+ (unless (url-type url)
+ (setf (url-type url) "gopher"))
+ (when (or (equal "gopher" (url-type url))
+ (equal "gophers" (url-type url)))
+ ;; Gopher defaults
+ (unless (url-host url)
+ (setf (url-host url) (url-filename url))
+ (setf (url-filename url) ""))
+ (when (or (equal (url-filename url) "")
+ (equal (url-filename url) "/"))
+ (setf (url-filename url) "/1")))
+ (when (equal "gemini" (url-type url))
+ ;; Gemini defaults
+ (if (equal (url-filename url) "")
+ (setf (url-filename url) "/"))))
+ url)
+ (set-match-data data))))
+
+(defun elpher-make-gopher-address (type selector host port &optional tls)
+ "Create an ADDRESS object using gopher directory record attributes.
+The basic attributes include: TYPE, SELECTOR, HOST and PORT.
+If the optional attribute TLS is non-nil, the address will be marked as
+requiring gopher-over-TLS."
+ (cond
+ ((and (equal type ?h)
+ (string-prefix-p "URL:" selector))
+ (elpher-address-from-url (elt (split-string selector "URL:") 1)))
+ ((equal type ?8)
+ (elpher-address-from-url
+ (concat "telnet"
+ "://" host
+ ":" (number-to-string port))))
+ (t
+ (elpher-address-from-url
+ (concat "gopher" (if tls "s" "")
+ "://" host
+ ":" (number-to-string port)
+ "/" (string type)
+ selector)))))
+
+(defun elpher-make-special-address (type)
+ "Create an ADDRESS object corresponding to the given special page symbol TYPE."
+ type)
+
+(defun elpher-address-to-url (address)
+ "Get string representation of ADDRESS, or nil if ADDRESS is special."
+ (if (not (elpher-address-special-p address))
+ (url-encode-url (url-recreate-url address))
+ nil))
(defun elpher-address-type (address)
- "Retrieve type from ADDRESS."
- (elt address 0))
-
-(defun elpher-address-selector (address)
- "Retrieve selector from ADDRESS."
- (elt address 1))
+ "Retrieve type of ADDRESS object.
+This is used to determine how to retrieve and render the document the
+address refers to, via the table `elpher-type-map'."
+ (if (symbolp address)
+ (list 'special address)
+ (let ((protocol (url-type address)))
+ (cond ((or (equal protocol "gopher")
+ (equal protocol "gophers"))
+ (list 'gopher
+ (if (member (url-filename address) '("" "/"))
+ ?1
+ (string-to-char (substring (url-filename address) 1)))))
+ ((equal protocol "gemini")
+ 'gemini)
+ ((equal protocol "telnet")
+ 'telnet)
+ (t 'other-url)))))
+
+(defun elpher-address-protocol (address)
+ "Retrieve the transport protocol for ADDRESS. This is nil for special addresses."
+ (if (symbolp address)
+ nil
+ (url-type address)))
+
+(defun elpher-address-filename (address)
+ "Retrieve the filename component of ADDRESS.
+For gopher addresses this is a combination of the selector type and selector."
+ (if (symbolp address)
+ nil
+ (url-filename address)))
(defun elpher-address-host (address)
- "Retrieve host from ADDRESS."
- (elt address 2))
+ "Retrieve host from ADDRESS object."
+ (url-host address))
(defun elpher-address-port (address)
- "Retrieve port from ADDRESS."
- (elt address 3))
+ "Retrieve port from ADDRESS object."
+ (if (symbolp address)
+ nil)
+ (if (> (url-port address) 0)
+ (url-port address)
+ (or (and (or (equal (url-type address) "gopher")
+ (equal (url-type address) "gophers"))
+ 70)
+ (and (equal (url-type address) "gemini")
+ 1965))))
(defun elpher-address-special-p (address)
- "Return non-nil if ADDRESS is special (e.g. start page, bookmarks page)."
- (not (elpher-address-host address)))
+ "Return non-nil if ADDRESS object is special (e.g. start page, bookmarks page)."
+ (symbolp address))
+
+(defun elpher-address-gopher-p (address)
+ "Return non-nill if ADDRESS object is a gopher address."
+ (and (not (elpher-address-special-p address))
+ (member (elpher-address-protocol address) '("gopher gophers"))))
+
+(defun elpher-gopher-address-selector (address)
+ "Retrieve gopher selector from ADDRESS object."
+ (if (member (url-filename address) '("" "/"))
+ ""
+ (substring (url-filename address) 2)))
;; Node
(defun elpher-make-node (display-string address &optional parent)
- "Create a node in the gopher page hierarchy.
+ "Create a node in the page hierarchy.
DISPLAY-STRING records the display string used for the page.
-ADDRESS specifies the address of the gopher page.
+ADDRESS specifies the address object of the page.
The optional PARENT specifies the parent node in the hierarchy.
This is set every time the node is visited, so while it forms
(elt node 0))
(defun elpher-node-address (node)
- "Retrieve the address of NODE."
+ "Retrieve the ADDRESS object of NODE."
(elt node 1))
(defun elpher-node-parent (node)
(defvar elpher-current-node nil)
-(defun elpher-visit-node (node &optional getter preserve-parent)
- "Visit NODE using its own getter or GETTER, if non-nil.
+(defun elpher-visit-node (node &optional renderer preserve-parent)
+ "Visit NODE using its own renderer or RENDERER, if non-nil.
Additionally, set the parent of NODE to `elpher-current-node',
unless PRESERVE-PARENT is non-nil."
(elpher-save-pos)
(elpher-set-node-parent node (elpher-node-parent elpher-current-node))
(elpher-set-node-parent node elpher-current-node)))
(setq elpher-current-node node)
- (if getter
- (funcall getter)
- (let* ((address (elpher-node-address node))
- (type (elpher-address-type address)))
- (funcall (car (alist-get type elpher-type-map))))))
+ (let* ((address (elpher-node-address node))
+ (type (elpher-address-type address))
+ (type-record (cdr (assoc type elpher-type-map))))
+ (if type-record
+ (funcall (car type-record)
+ (if renderer
+ renderer
+ (cadr type-record)))
+ (elpher-visit-parent-node)
+ (pcase type
+ (`(gopher ,type-char)
+ (error "Unsupported gopher selector type '%c' for '%s'"
+ type-char (elpher-address-to-url address)))
+ (other
+ (error "Unsupported address type '%S' for '%s'"
+ other (elpher-address-to-url address)))))))
(defun elpher-visit-parent-node ()
"Visit the parent of the current node."
(defun elpher-update-header ()
"If `elpher-use-header' is true, display current node info in window header."
(if elpher-use-header
- (setq header-line-format (elpher-node-display-string elpher-current-node))))
+ (let* ((display-string (elpher-node-display-string elpher-current-node))
+ (address (elpher-node-address elpher-current-node))
+ (url-string (if (elpher-address-special-p address)
+ ""
+ (concat " - " (elpher-address-to-url address) "")))
+ (header (replace-regexp-in-string "%" "%%" (concat display-string
+ url-string))))
+ (setq header-line-format header))))
(defmacro elpher-with-clean-buffer (&rest args)
"Evaluate ARGS with a clean *elpher* buffer as current."
args)))
-;;; Index rendering
+;;; Text Processing
;;
+(defvar elpher-user-coding-system nil
+ "User-specified coding system to use for decoding text responses.")
+
+(defun elpher-decode (string)
+ "Decode STRING using autodetected or user-specified coding system."
+ (decode-coding-string string
+ (if elpher-user-coding-system
+ elpher-user-coding-system
+ (detect-coding-string string t))))
+
(defun elpher-preprocess-text-response (string)
- "Clear away CRs and terminating period from STRING."
- (replace-regexp-in-string "\n\.\n$" "\n"
- (replace-regexp-in-string "\r" ""
- string)))
+ "Preprocess text selector response contained in STRING.
+This involes decoding the character representation, and clearing
+away CRs and any terminating period."
+ (elpher-decode (replace-regexp-in-string "\n\.\n$" "\n"
+ (replace-regexp-in-string "\r" "" string))))
+
+
+;;; Network error reporting
+;;
+
+(defun elpher-network-error (address error)
+ "Display ERROR message following unsuccessful negotiation with ADDRESS."
+ (elpher-with-clean-buffer
+ (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
+ "When attempting to retrieve " (elpher-address-to-url address) ":\n"
+ (error-message-string error) "\n"
+ (propertize "\n----------------\n\n" 'face 'error)
+ "Press 'u' to return to the previous page.")))
+
+
+;;; Gopher selector retrieval
+;;
+
+(defun elpher-process-cleanup ()
+ "Immediately shut down any extant elpher process."
+ (let ((p (get-process "elpher-process")))
+ (if p (delete-process p))))
+
+(defvar elpher-use-tls nil
+ "If non-nil, use TLS to communicate with gopher servers.")
+
+(defvar elpher-selector-string)
+
+(defun elpher-get-selector (address after &optional propagate-error)
+ "Retrieve selector specified by ADDRESS, then execute AFTER.
+The result is stored as a string in the variable ‘elpher-selector-string’.
+
+Usually errors result in an error page being displayed. This is only
+appropriate if the selector is to be directly viewed. If PROPAGATE-ERROR
+is non-nil, this message is not displayed. Instead, the error propagates
+up to the calling function."
+ (setq elpher-selector-string "")
+ (when (equal (elpher-address-protocol address) "gophers")
+ (if (gnutls-available-p)
+ (when (not elpher-use-tls)
+ (setq elpher-use-tls t)
+ (message "Engaging TLS gopher mode."))
+ (error "Cannot retrieve TLS gopher selector: GnuTLS not available")))
+ (condition-case the-error
+ (let* ((kill-buffer-query-functions nil)
+ (proc (open-network-stream "elpher-process"
+ nil
+ (elpher-address-host address)
+ (elpher-address-port address)
+ :type (if elpher-use-tls 'tls 'plain))))
+ (set-process-coding-system proc 'binary)
+ (set-process-filter proc
+ (lambda (_proc string)
+ (setq elpher-selector-string
+ (concat elpher-selector-string string))))
+ (set-process-sentinel proc after)
+ (let ((inhibit-eol-conversion t))
+ (process-send-string proc
+ (concat (elpher-gopher-address-selector address) "\r\n"))))
+ (error
+ (if (and (consp the-error)
+ (eq (car the-error) 'gnutls-error)
+ (not (equal (elpher-address-protocol address) "gophers"))
+ (or elpher-auto-disengage-TLS
+ (yes-or-no-p "Could not establish encrypted connection. Disable TLS mode? ")))
+ (progn
+ (message "Disengaging TLS gopher mode.")
+ (setq elpher-use-tls nil)
+ (elpher-get-selector address after))
+ (elpher-process-cleanup)
+ (if propagate-error
+ (error the-error)
+ (elpher-with-clean-buffer
+ (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
+ "Failed to connect to " (elpher-address-to-url address) ".\n"
+ (propertize "\n----------------\n\n" 'face 'error)
+ "Press 'u' to return to the previous page.")))))))
+
+(defun elpher-get-gopher-node (renderer)
+ "Getter function for gopher nodes.
+The RENDERER procedure is used to display the contents of the node
+once they are retrieved from the gopher server."
+ (let* ((address (elpher-node-address elpher-current-node))
+ (content (elpher-get-cached-content address)))
+ (if (and content (funcall renderer nil))
+ (elpher-with-clean-buffer
+ (insert content)
+ (elpher-restore-pos))
+ (elpher-with-clean-buffer
+ (insert "LOADING... (use 'u' to cancel)"))
+ (elpher-get-selector address
+ (lambda (_proc event)
+ (unless (string-prefix-p "deleted" event)
+ (funcall renderer elpher-selector-string)
+ (elpher-restore-pos)))))))
+
+;; Index rendering
(defun elpher-insert-index (string)
"Insert the index corresponding to STRING into the current buffer."
;; LF-only servers sadly exist, hence the following.
(let ((str-processed (elpher-preprocess-text-response string)))
(dolist (line (split-string str-processed "\n"))
- (unless (= (length line) 0)
- (let* ((type (elt line 0))
- (fields (split-string (substring line 1) "\t"))
- (display-string (elt fields 0))
- (selector (elt fields 1))
- (host (elt fields 2))
- (port (if (elt fields 3)
- (string-to-number (elt fields 3))
- nil)))
- (elpher-insert-index-record display-string type selector host port))))))
+ (ignore-errors
+ (unless (= (length line) 0)
+ (let* ((type (elt line 0))
+ (fields (split-string (substring line 1) "\t"))
+ (display-string (elt fields 0))
+ (selector (elt fields 1))
+ (host (elt fields 2))
+ (port (if (elt fields 3)
+ (string-to-number (elt fields 3))
+ nil))
+ (address (elpher-make-gopher-address type selector host port)))
+ (elpher-insert-index-record display-string address)))))))
(defun elpher-insert-margin (&optional type-name)
"Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
(defun elpher-node-button-help (node)
"Return a string containing the help text for a button corresponding to NODE."
(let ((address (elpher-node-address node)))
- (if (eq (elpher-address-type address) ?h)
- (let ((url (cadr (split-string (elpher-address-selector address) "URL:"))))
- (format "mouse-1, RET: open url '%s'" url))
- (format "mouse-1, RET: open '%s' on %s port %s"
- (elpher-address-selector address)
- (elpher-address-host address)
- (elpher-address-port address)))))
-
-(defun elpher-insert-index-record (display-string type selector host port)
+ (format "mouse-1, RET: open '%s'" (elpher-address-to-url address))))
+
+(defun elpher-insert-index-record (display-string &optional address)
"Function to insert an index record into the current buffer.
-The contents of the record are dictated by TYPE, DISPLAY-STRING, SELECTOR, HOST
-and PORT."
- (let ((address (elpher-make-address type selector host port))
- (type-map-entry (alist-get type elpher-type-map)))
+The contents of the record are dictated by DISPLAY-STRING and ADDRESS.
+If ADDRESS is not supplied or nil the record is rendered as an
+'information' line."
+ (let* ((type (if address (elpher-address-type address) nil))
+ (type-map-entry (cdr (assoc type elpher-type-map))))
(if type-map-entry
- (let* ((margin-code (elt type-map-entry 1))
- (face (elt type-map-entry 2))
+ (let* ((margin-code (elt type-map-entry 2))
+ (face (elt type-map-entry 3))
(node (elpher-make-node display-string address)))
(elpher-insert-margin margin-code)
(insert-text-button display-string
'follow-link t
'help-echo (elpher-node-button-help node)))
(pcase type
- (?i ;; Information
+ ((or '(gopher ?i) 'nil) ;; Information
(elpher-insert-margin)
- (insert (propertize
- (if elpher-buttonify-urls-in-directories
- (elpher-buttonify-urls display-string)
- display-string)
- 'face 'elpher-info)))
- (other ;; Unknown
- (elpher-insert-margin (concat (char-to-string type) "?"))
+ (let ((propertized-display-string
+ (propertize display-string 'face 'elpher-info)))
+ (insert (if elpher-buttonify-urls-in-directories
+ (elpher-buttonify-urls propertized-display-string)
+ propertized-display-string))))
+ (`(gopher ,selector-type) ;; Unknown
+ (elpher-insert-margin (concat (char-to-string selector-type) "?"))
(insert (propertize display-string
'face 'elpher-unknown)))))
(insert "\n")))
(let ((node (button-get button 'elpher-node)))
(elpher-visit-node node)))
+(defun elpher-render-index (data &optional _mime-type-string)
+ "Render DATA as an index. MIME-TYPE-STRING is unused."
+ (elpher-with-clean-buffer
+ (if (not data)
+ t
+ (elpher-insert-index data)
+ (elpher-cache-content (elpher-node-address elpher-current-node)
+ (buffer-string)))))
-;;; Selector retrieval (all kinds)
-;;
-
-(defun elpher-process-cleanup ()
- "Immediately shut down any extant elpher process."
- (let ((p (get-process "elpher-process")))
- (if p (delete-process p))))
-
-(defvar elpher-selector-string)
-
-(defun elpher-get-selector (address after)
- "Retrieve selector specified by ADDRESS, then execute AFTER.
-The result is stored as a string in the variable ‘elpher-selector-string’."
- (setq elpher-selector-string "")
- (condition-case nil
- (progn
- (make-network-process :name "elpher-process"
- :host (elpher-address-host address)
- :service (elpher-address-port address)
- :filter (lambda (proc string)
- (setq elpher-selector-string
- (concat elpher-selector-string string)))
- :sentinel after)
- (process-send-string "elpher-process"
- (concat (elpher-address-selector address) "\n")))
- (error
- (elpher-with-clean-buffer
- (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
- "Failed to connect to " (elpher-get-address-url address) ".\n"
- (propertize "\n----------------\n\n" 'face 'error)
- "Press 'u' to return to the previous page.")))))
-
-;; Index retrieval
-
-(defun elpher-get-index-node ()
- "Getter which retrieves the current node contents as an index."
- (let* ((address (elpher-node-address elpher-current-node))
- (content (elpher-get-cached-content address)))
- (if content
- (progn
- (elpher-with-clean-buffer
- (insert content)
- (elpher-restore-pos)))
- (elpher-with-clean-buffer
- (insert "LOADING DIRECTORY... (use 'u' to cancel)"))
- (elpher-get-selector address
- (lambda (proc event)
- (unless (string-prefix-p "deleted" event)
- (elpher-with-clean-buffer
- (elpher-insert-index elpher-selector-string)
- (elpher-restore-pos)
- (elpher-cache-content
- (elpher-node-address elpher-current-node)
- (buffer-string)))))))))
-
-;; Text retrieval
+;; Text rendering
(defconst elpher-url-regex
- "\\([a-zA-Z]+\\)://\\([a-zA-Z0-9.\-]+\\)\\(?3::[0-9]+\\)?\\(?4:/[^ \r\n\t(),]*\\)?"
- "Regexp used to locate and buttinofy URLs in text files loaded by elpher.")
-
-(defun elpher-make-node-from-matched-url (&optional string)
- "Convert most recent `elpher-url-regex' match to a node.
-
-If STRING is non-nil, this is given as an argument to all `match-string'
-calls, as is necessary if the match is performed by `string-match'."
- (let ((url (match-string 0 string))
- (protocol (downcase (match-string 1 string))))
- (if (string= protocol "gopher")
- (let* ((host (match-string 2 string))
- (port (if (> (length (match-string 3 string)) 1)
- (string-to-number (substring (match-string 3 string) 1))
- 70))
- (type-and-selector (match-string 4 string))
- (type (if (> (length type-and-selector) 1)
- (elt type-and-selector 1)
- ?1))
- (selector (if (> (length type-and-selector) 1)
- (substring type-and-selector 2)
- ""))
- (address (elpher-make-address type selector host port)))
- (elpher-make-node url address))
- (let* ((host (match-string 2 string))
- (port (if (> (length (match-string 3 string)) 1)
- (string-to-number (substring (match-string 3 string) 1))
- 70))
- (selector (concat "URL:" url))
- (address (elpher-make-address ?h selector host port)))
- (elpher-make-node url address)))))
-
+ "\\([a-zA-Z]+\\)://\\([a-zA-Z0-9.\-]*[a-zA-Z0-9\-]\\|\[[a-zA-Z0-9:]+\]\\)\\(:[0-9]+\\)?\\(/\\([0-9a-zA-Z\-_~?/@|:.]*[0-9a-zA-Z\-_~?/@|]\\)?\\)?"
+ "Regexp used to locate and buttniofy URLs in text files loaded by elpher.")
(defun elpher-buttonify-urls (string)
"Turn substrings which look like urls in STRING into clickable buttons."
(insert string)
(goto-char (point-min))
(while (re-search-forward elpher-url-regex nil t)
- (let ((node (elpher-make-node-from-matched-url)))
+ (let ((node (elpher-make-node (substring-no-properties (match-string 0))
+ (elpher-address-from-url (match-string 0)))))
(make-text-button (match-beginning 0)
(match-end 0)
'elpher-node node
'action #'elpher-click-link
'follow-link t
- 'help-echo (elpher-node-button-help node))))
+ 'help-echo (elpher-node-button-help node)
+ 'face 'button)))
(buffer-string)))
-(defun elpher-get-text-node ()
- "Getter which retrieves the current node contents as a text document."
- (let* ((address (elpher-node-address elpher-current-node))
- (content (elpher-get-cached-content address)))
- (if content
- (progn
- (elpher-with-clean-buffer
- (insert content)
- (elpher-restore-pos)))
- (progn
- (elpher-with-clean-buffer
- (insert "LOADING TEXT... (use 'u' to cancel)"))
- (elpher-get-selector address
- (lambda (proc event)
- (unless (string-prefix-p "deleted" event)
- (elpher-with-clean-buffer
- (insert (elpher-buttonify-urls
- (elpher-preprocess-text-response
- elpher-selector-string)))
- (elpher-restore-pos)
- (elpher-cache-content
- (elpher-node-address elpher-current-node)
- (buffer-string))))))))))
+(defun elpher-render-text (data &optional _mime-type-string)
+ "Render DATA as text. MIME-TYPE-STRING is unused."
+ (elpher-with-clean-buffer
+ (if (not data)
+ t
+ (insert (elpher-buttonify-urls (elpher-preprocess-text-response data)))
+ (elpher-cache-content
+ (elpher-node-address elpher-current-node)
+ (buffer-string)))))
;; Image retrieval
-(defun elpher-get-image-node ()
- "Getter which retrieves the current node contents as an image to view."
- (let* ((address (elpher-node-address elpher-current-node))
- (content (elpher-get-cached-content address)))
- (if content
+(defun elpher-render-image (data &optional _mime-type-string)
+ "Display DATA as image. MIME-TYPE-STRING is unused."
+ (if (not data)
+ nil
+ (if (display-images-p)
(progn
- (elpher-with-clean-buffer
- (insert-image content)
- (elpher-restore-pos)))
- (if (display-images-p)
- (progn
+ (let ((image (create-image
+ data
+ nil t)))
(elpher-with-clean-buffer
- (insert "LOADING IMAGE... (use 'u' to cancel)"))
- (elpher-get-selector address
- (lambda (proc event)
- (unless (string-prefix-p "deleted" event)
- (let ((image (create-image
- (encode-coding-string
- elpher-selector-string
- 'no-conversion)
- nil t)))
- (elpher-with-clean-buffer
- (insert-image image)
- (elpher-restore-pos))
- (if elpher-cache-images
- (elpher-cache-content
- (elpher-node-address elpher-current-node)
- image)))))))
- (elpher-get-node-download)))))
-
-;; Search retrieval
-
-(defun elpher-get-search-node ()
- "Getter which submits a search query to the address of the current node."
- (let* ((address (elpher-node-address elpher-current-node))
- (content (elpher-get-cached-content address))
- (aborted t))
- (if content
- (progn
- (elpher-with-clean-buffer
- (insert content)
- (elpher-restore-pos))
- (message "Displaying cached search results. Reload to perform a new search."))
+ (insert-image image)
+ (elpher-restore-pos))))
+ (elpher-render-download data))))
+
+;; Search retrieval and rendering
+
+(defun elpher-get-gopher-query-node (renderer)
+ "Getter for gopher addresses requiring input.
+The response is rendered using the rendering function RENDERER."
+ (let* ((address (elpher-node-address elpher-current-node))
+ (content (elpher-get-cached-content address))
+ (aborted t))
+ (if (and content (funcall renderer nil))
+ (elpher-with-clean-buffer
+ (insert content)
+ (elpher-restore-pos)
+ (message "Displaying cached search results. Reload to perform a new search."))
(unwind-protect
(let* ((query-string (read-string "Query: "))
- (query-selector (concat (elpher-address-selector address) "\t" query-string))
- (search-address (elpher-make-address ?1
- query-selector
- (elpher-address-host address)
- (elpher-address-port address))))
+ (query-selector (concat (elpher-gopher-address-selector address) "\t" query-string))
+ (search-address (elpher-make-gopher-address ?1
+ query-selector
+ (elpher-address-host address)
+ (elpher-address-port address)
+ (equal (elpher-address-type address) "gophers"))))
(setq aborted nil)
+
(elpher-with-clean-buffer
(insert "LOADING RESULTS... (use 'u' to cancel)"))
(elpher-get-selector search-address
- (lambda (proc event)
- (unless (string-prefix-p "deleted" event)
- (elpher-with-clean-buffer
- (elpher-insert-index elpher-selector-string))
- (goto-char (point-min))
- (elpher-cache-content
- (elpher-node-address elpher-current-node)
- (buffer-string))))))
+ (lambda (_proc event)
+ (unless (string-prefix-p "deleted" event)
+ (funcall renderer elpher-selector-string)
+ (elpher-restore-pos)))))
(if aborted
(elpher-visit-parent-node))))))
-
-;; Raw server response retrieval
-
-(defun elpher-get-node-raw ()
- "Getter which retrieves the raw server response for the current node."
- (let ((address (elpher-node-address elpher-current-node)))
- (elpher-with-clean-buffer
- (insert "LOADING RAW SERVER RESPONSE... (use 'u' to cancel)"))
- (if address
- (elpher-get-selector address
- (lambda (proc event)
- (unless (string-prefix-p "deleted" event)
- (elpher-with-clean-buffer
- (insert elpher-selector-string)
- (goto-char (point-min))))))
- (progn
- (elpher-with-clean-buffer
- (insert elpher-start-index))
- (goto-char (point-min)))))
- (message "Displaying raw server response. Reload or redraw to return to standard view."))
-;; File export retrieval
+;; Raw server response rendering
-(defvar elpher-download-filename)
+(defun elpher-render-raw (data &optional _mime-type-string)
+ "Display raw DATA in buffer. MIME-TYPE-STRING is unused."
+ (if (not data)
+ nil
+ (elpher-with-clean-buffer
+ (insert data)
+ (goto-char (point-min)))
+ (message "Displaying raw server response. Reload or redraw to return to standard view.")))
+
+;; File save "rendering"
+
+(defun elpher-render-download (data &optional _mime-type-string)
+ "Save DATA to file. MIME-TYPE-STRING is unused."
+ (if (not data)
+ nil
+ (let* ((address (elpher-node-address elpher-current-node))
+ (selector (elpher-gopher-address-selector address)))
+ (elpher-visit-parent-node) ; Do first in case of non-local exits.
+ (let* ((filename-proposal (file-name-nondirectory selector))
+ (filename (read-file-name "Download complete. Save file as: "
+ nil nil nil
+ (if (> (length filename-proposal) 0)
+ filename-proposal
+ "download.file"))))
+ (let ((coding-system-for-write 'binary))
+ (with-temp-file filename
+ (insert data)))
+ (message (format "Saved to file %s." filename))))))
+
+;; HTML rendering
+
+(defun elpher-render-html (data &optional _mime-type-string)
+ "Render DATA as HTML using shr. MIME-TYPE-STRING is unused."
+ (elpher-with-clean-buffer
+ (if (not data)
+ t
+ (let ((dom (with-temp-buffer
+ (insert data)
+ (libxml-parse-html-region (point-min) (point-max)))))
+ (shr-insert-document dom)))))
+
+;; Gemini node retrieval
+
+(defvar elpher-gemini-response)
+
+(defun elpher-get-gemini-response (address after)
+ "Retrieve gemini ADDRESS, then execute AFTER.
+The response is stored in the variable ‘elpher-gemini-response’."
+ (setq elpher-gemini-response "")
+ (if (not (gnutls-available-p))
+ (error "Cannot establish gemini connection: GnuTLS not available")
+ (condition-case the-error
+ (let* ((kill-buffer-query-functions nil)
+ (proc (open-network-stream "elpher-process"
+ nil
+ (elpher-address-host address)
+ (elpher-address-port address)
+ :type 'tls)))
+ (set-process-coding-system proc 'binary)
+ (set-process-filter proc
+ (lambda (_proc string)
+ (setq elpher-gemini-response
+ (concat elpher-gemini-response string))))
+ (set-process-sentinel proc after)
+ (let ((inhibit-eol-conversion t))
+ (process-send-string proc
+ (concat (elpher-address-to-url address) "\r\n"))))
+ (error
+ (error "Error initiating connection to server")))))
+
+(defun elpher-parse-gemini-response (response)
+ "Parse the RESPONSE string and return a list of components
+The list is of the form (code meta body). A response of nil implies
+that the response was malformed."
+ (let ((header-end-idx (string-match "\r\n" response)))
+ (if header-end-idx
+ (let ((header (string-trim (substring response 0 header-end-idx)))
+ (body (substring response (+ header-end-idx 2))))
+ (if (>= (length header) 2)
+ (let ((code (substring header 0 2))
+ (meta (string-trim (substring header 2))))
+ (list code meta body))
+ (error "Malformed response: No response status found in header %s" header)))
+ (error "Malformed response: No CRLF-delimited header found"))))
+
+
+(defun elpher-process-gemini-response (renderer)
+ "Process the gemini response and pass the result to RENDERER.
+The response is assumed to be in the variable `elpher-gemini-response'."
+ (condition-case the-error
+ (let ((response-components (elpher-parse-gemini-response elpher-gemini-response)))
+ (let ((response-code (elt response-components 0))
+ (response-meta (elt response-components 1))
+ (response-body (elt response-components 2)))
+ (pcase (elt response-code 0)
+ (?1 ; Input required
+ (elpher-with-clean-buffer
+ (insert "Gemini server is requesting input."))
+ (let* ((query-string (read-string (concat response-meta ": ")))
+ (url (elpher-address-to-url (elpher-node-address elpher-current-node)))
+ (query-address (elpher-address-from-url (concat url "?" query-string))))
+ (elpher-get-gemini-response query-address
+ (lambda (_proc event)
+ (unless (string-prefix-p "deleted" event)
+ (funcall #'elpher-process-gemini-response
+ renderer)
+ (elpher-restore-pos))))))
+ (?2 ; Normal response
+ ;; (message response-header)
+ (funcall renderer response-body response-meta))
+ (?3 ; Redirect
+ (message "Following redirect to %s" response-meta)
+ (let ((redirect-address (elpher-address-from-gemini-url response-meta)))
+ (elpher-get-gemini-response redirect-address
+ (lambda (_proc event)
+ (unless (string-prefix-p "deleted" event)
+ (funcall #'elpher-process-gemini-response
+ renderer)
+ (elpher-restore-pos))))))
+ (?4 ; Temporary failure
+ (error "Gemini server reports TEMPORARY FAILURE for this request: %s %s"
+ response-code response-meta))
+ (?5 ; Permanent failure
+ (error "Gemini server reports PERMANENT FAILURE for this request: %s %s"
+ response-code response-meta))
+ (?6 ; Client certificate required
+ (error "Gemini server requires client certificate (unsupported at this time)"))
+ (_other
+ (error "Gemini server response unknown: %s %s"
+ response-code response-meta)))))
+ (error
+ (elpher-network-error (elpher-node-address elpher-current-node) the-error))))
-(defun elpher-get-node-download ()
- "Getter which retrieves the current node and writes the result to a file."
- (let* ((address (elpher-node-address elpher-current-node))
- (selector (elpher-address-selector address)))
- (elpher-visit-parent-node) ; Do first in case of non-local exits.
- (let* ((filename-proposal (file-name-nondirectory selector))
- (filename (read-file-name "Save file as: "
- nil nil nil
- (if (> (length filename-proposal) 0)
- filename-proposal
- "gopher.file"))))
- (message "Downloading...")
- (setq elpher-download-filename filename)
- (elpher-get-selector address
- (lambda (proc event)
- (let ((coding-system-for-write 'binary))
- (with-temp-file elpher-download-filename
- (insert elpher-selector-string)
- (message (format "Download complate, saved to file %s."
- elpher-download-filename)))))))))
-
-;; URL retrieval
-
-(defun elpher-insert-rendered-html (string)
- "Use shr to insert rendered view of html STRING into current buffer."
- (let ((dom (with-temp-buffer
- (insert string)
- (libxml-parse-html-region (point-min) (point-max)))))
- (shr-insert-document dom)))
-
-(defun elpher-get-url-node ()
- "Getter which attempts to open the URL specified by the current node."
+(defun elpher-get-gemini-node (renderer)
+ "Getter which retrieves and renders a Gemini node and renders it using RENDERER."
(let* ((address (elpher-node-address elpher-current-node))
- (selector (elpher-address-selector address)))
- (let ((url (elt (split-string selector "URL:") 1)))
- (if url
- (progn
- (elpher-visit-parent-node) ; Do first in case of non-local exits.
- (message "Opening URL...")
- (if elpher-open-urls-with-eww
- (browse-web url)
- (browse-url url)))
- (let ((content (elpher-get-cached-content address)))
- (if content
- (progn
- (elpher-with-clean-buffer
- (insert content)
- (elpher-restore-pos)))
+ (content (elpher-get-cached-content address)))
+ (condition-case the-error
+ (if (and content (funcall renderer nil))
(elpher-with-clean-buffer
- (insert "LOADING HTML... (use 'u' to cancel)"))
- (elpher-get-selector address
- (lambda (proc event)
- (unless (string-prefix-p "deleted" event)
- (elpher-with-clean-buffer
- (elpher-insert-rendered-html elpher-selector-string)
- (goto-char (point-min))
- (elpher-cache-content
- (elpher-node-address elpher-current-node)
- (buffer-string))))))))))))
+ (insert content)
+ (elpher-restore-pos))
+ (elpher-with-clean-buffer
+ (insert "LOADING GEMINI... (use 'u' to cancel)"))
+ (elpher-get-gemini-response address
+ (lambda (_proc event)
+ (unless (string-prefix-p "deleted" event)
+ (funcall #'elpher-process-gemini-response
+ renderer)
+ (elpher-restore-pos)))))
+ (error
+ (elpher-network-error address the-error)))))
+
+
+(defun elpher-render-gemini (body &optional mime-type-string)
+ "Render gemini response BODY with rendering MIME-TYPE-STRING."
+ (if (not body)
+ t
+ (let* ((mime-type-string* (if (or (not mime-type-string)
+ (string-empty-p mime-type-string))
+ "text/gemini; charset=utf-8"
+ mime-type-string))
+ (mime-type-split (split-string mime-type-string* ";" t))
+ (mime-type (string-trim (car mime-type-split)))
+ (parameters (mapcar (lambda (s)
+ (let ((key-val (split-string s "=")))
+ (list (downcase (string-trim (car key-val)))
+ (downcase (string-trim (cadr key-val))))))
+ (cdr mime-type-split))))
+ (when (string-prefix-p "text/" mime-type)
+ (setq body (decode-coding-string
+ body
+ (if (assoc "charset" parameters)
+ (intern (cadr (assoc "charset" parameters)))
+ 'utf-8)))
+ (setq body (replace-regexp-in-string "\r" "" body)))
+ (pcase mime-type
+ ((or "text/gemini" "")
+ (elpher-render-gemini-map body parameters))
+ ((pred (string-prefix-p "text/"))
+ (elpher-render-gemini-plain-text body parameters))
+ ((pred (string-prefix-p "image/"))
+ (elpher-render-image body))
+ (_other
+ (error "Unsupported MIME type %S" mime-type))))))
+
+(defun elpher-gemini-get-link-url (line)
+ "Extract the url portion of LINE, a gemini map file link line."
+ (string-trim (elt (split-string (substring line 2)) 0)))
+
+(defun elpher-gemini-get-link-display-string (line)
+ "Extract the display string portion of LINE, a gemini map file link line."
+ (let* ((rest (string-trim (elt (split-string line "=>") 1)))
+ (idx (string-match "[ \t]" rest)))
+ (if idx
+ (string-trim (substring rest (+ idx 1)))
+ "")))
+
+(defun elpher-collapse-dot-sequences (filename)
+ "Collapse dot sequences in FILENAME.
+For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
+ (let* ((path (split-string filename "/"))
+ (path-reversed-normalized
+ (seq-reduce (lambda (a b)
+ (cond ((and a (equal b "..") (cdr a)))
+ ((and (not a) (equal b "..")) a) ;leading .. are dropped
+ ((equal b ".") a)
+ (t (cons b a))))
+ path nil)))
+ (string-join (reverse path-reversed-normalized) "/")))
+
+(defun elpher-address-from-gemini-url (url)
+ "Extract address from URL with defaults as per gemini map files."
+ (let ((address (url-generic-parse-url url)))
+ (unless (and (url-type address) (not (url-fullness address))) ;avoid mangling mailto: urls
+ (setf (url-fullness address) t)
+ (unless (url-host address) ;if there is an explicit host, filenames are absolute
+ (setf (url-host address) (url-host (elpher-node-address elpher-current-node)))
+ (unless (string-prefix-p "/" (url-filename address)) ;deal with relative links
+ (setf (url-filename address)
+ (concat (file-name-directory
+ (url-filename (elpher-node-address elpher-current-node)))
+ (url-filename address)))))
+ (unless (url-type address)
+ (setf (url-type address) "gemini"))
+ (if (equal (url-type address) "gemini")
+ (setf (url-filename address)
+ (elpher-collapse-dot-sequences (url-filename address)))))
+ address))
+
+(defun elpher-render-gemini-map (data _parameters)
+ "Render DATA as a gemini map file, PARAMETERS is currently unused."
+ (elpher-with-clean-buffer
+ (dolist (line (split-string data "\n"))
+ (if (string-prefix-p "=>" line)
+ (let* ((url (elpher-gemini-get-link-url line))
+ (display-string (elpher-gemini-get-link-display-string line))
+ (address (elpher-address-from-gemini-url url)))
+ (if (> (length display-string) 0)
+ (elpher-insert-index-record display-string address)
+ (elpher-insert-index-record url address)))
+ (elpher-insert-index-record line)))
+ (elpher-cache-content
+ (elpher-node-address elpher-current-node)
+ (buffer-string))))
+
+(defun elpher-render-gemini-plain-text (data _parameters)
+ "Render DATA as plain text file. PARAMETERS is currently unused."
+ (elpher-with-clean-buffer
+ (insert (elpher-buttonify-urls data))
+ (elpher-cache-content
+ (elpher-node-address elpher-current-node)
+ (buffer-string))))
+
+;; Other URL node opening
+
+(defun elpher-get-other-url-node (renderer)
+ "Getter which attempts to open the URL specified by the current node (RENDERER must be nil)."
+ (when renderer
+ (elpher-visit-parent-node)
+ (error "Command not supported for general URLs"))
+ (let* ((address (elpher-node-address elpher-current-node))
+ (url (elpher-address-to-url address)))
+ (progn
+ (elpher-visit-parent-node) ; Do first in case of non-local exits.
+ (message "Opening URL...")
+ (if elpher-open-urls-with-eww
+ (browse-web url)
+ (browse-url url)))))
;; Telnet node connection
-(defun elpher-get-telnet-node ()
- "Getter which opens a telnet connection to the server specified by the current node."
+(defun elpher-get-telnet-node (renderer)
+ "Opens a telnet connection to the current node address (RENDERER must be nil)."
+ (when renderer
+ (elpher-visit-parent-node)
+ (error "Command not supported for telnet URLs"))
(let* ((address (elpher-node-address elpher-current-node))
(host (elpher-address-host address))
(port (elpher-address-port address)))
;; Start page node retrieval
-(defun elpher-get-start-node ()
- "Getter which displays the start page."
+(defun elpher-get-start-node (renderer)
+ "Getter which displays the start page (RENDERER must be nil)."
+ (when renderer
+ (elpher-visit-parent-node)
+ (error "Command not supported for start page"))
(elpher-with-clean-buffer
- (elpher-insert-index elpher-start-index)
+ (insert " --------------------------------------------\n"
+ " Elpher Gopher Client \n"
+ " version " elpher-version "\n"
+ " --------------------------------------------\n"
+ "\n"
+ "Default bindings:\n"
+ "\n"
+ " - TAB/Shift-TAB: next/prev item on current page\n"
+ " - RET/mouse-1: open item under cursor\n"
+ " - m: select an item on current page by name (autocompletes)\n"
+ " - u/mouse-3: return to previous page\n"
+ " - o/O: visit different selector or the root menu of the current server\n"
+ " - g: go to a particular gopher address\n"
+ " - d/D: download item under cursor or current page\n"
+ " - i/I: info on item under cursor or current page\n"
+ " - c/C: copy URL representation of item under cursor or current page\n"
+ " - a/A: bookmark the item under cursor or current page\n"
+ " - x/X: remove bookmark for item under cursor or current page\n"
+ " - B: visit the bookmarks page\n"
+ " - r: redraw current page (using cached contents if available)\n"
+ " - R: reload current page (regenerates cache)\n"
+ " - S: set character coding system for gopher (default is to autodetect)\n"
+ " - T: toggle TLS gopher mode\n"
+ " - .: display the raw server response for the current page\n"
+ "\n"
+ "Start your exploration of gopher space:\n")
+ (elpher-insert-index-record "Floodgap Systems Gopher Server"
+ (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))
+ (insert "\n"
+ "Alternatively, select the following item and enter some search terms:\n")
+ (elpher-insert-index-record "Veronica-2 Gopher Search Engine"
+ (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))
+ (insert "\n"
+ "** Refer to the ")
+ (let ((help-string "RET,mouse-1: Open Elpher info manual (if available)"))
+ (insert-text-button "Elpher info manual"
+ 'face 'link
+ 'action (lambda (_)
+ (interactive)
+ (info "(elpher)"))
+ 'follow-link t
+ 'help-echo help-string))
+ (insert " for the full documentation. **\n")
+ (insert (propertize
+ (concat " (This should be available if you have installed Elpher using\n"
+ " MELPA. Otherwise you will have to install the manual yourself.)")
+ 'face 'shadow))
(elpher-restore-pos)))
;; Bookmarks page node retrieval
-(defun elpher-get-bookmarks-node ()
- "Getter to load and display the current bookmark list."
+(defun elpher-get-bookmarks-node (renderer)
+ "Getter to load and display the current bookmark list (RENDERER must be nil)."
+ (when renderer
+ (elpher-visit-parent-node)
+ (error "Command not supported for bookmarks page"))
(elpher-with-clean-buffer
(insert "---- Bookmark list ----\n\n")
(let ((bookmarks (elpher-load-bookmarks)))
(if bookmarks
(dolist (bookmark bookmarks)
(let ((display-string (elpher-bookmark-display-string bookmark))
- (address (elpher-bookmark-address bookmark)))
- (elpher-insert-index-record display-string
- (elpher-address-type address)
- (elpher-address-selector address)
- (elpher-address-host address)
- (elpher-address-port address))))
+ (address (elpher-address-from-url (elpher-bookmark-url bookmark))))
+ (elpher-insert-index-record display-string address)))
(insert "No bookmarks found.\n")))
(insert "\n-----------------------\n\n"
"- u: return to previous page\n"
;;; Bookmarks
;;
-(defun elpher-make-bookmark (display-string address)
+(defun elpher-make-bookmark (display-string url)
"Make an elpher bookmark.
DISPLAY-STRING determines how the bookmark will appear in the
-bookmark list, while ADDRESS is the address of the entry."
- (list display-string address))
+bookmark list, while URL is the url of the entry."
+ (list display-string url))
(defun elpher-bookmark-display-string (bookmark)
"Get the display string of BOOKMARK."
"Set the display string of BOOKMARK to DISPLAY-STRING."
(setcar bookmark display-string))
-(defun elpher-bookmark-address (bookmark)
+(defun elpher-bookmark-url (bookmark)
"Get the address for BOOKMARK."
(elt bookmark 1))
Beware that this completely replaces the existing contents of the file."
(with-temp-file (locate-user-emacs-file "elpher-bookmarks")
(erase-buffer)
- (insert "; Elpher gopher bookmarks file\n\n"
- "; Bookmarks are stored as a list of (label (type selector host port))\n"
- "; s-expressions, where type is stored as a character (i.e. 49 = ?1).\n"
- "; Feel free to edit by hand, but ensure this structure remains intact.\n\n")
+ (insert "; Elpher bookmarks file\n\n"
+ "; Bookmarks are stored as a list of (label URL) items.\n"
+ "; Feel free to edit by hand, but take care to ensure\n"
+ "; the list structure remains intact.\n\n")
(pp bookmarks (current-buffer))))
(defun elpher-load-bookmarks ()
"Get the list of bookmarks from the users's bookmark file."
- (with-temp-buffer
- (ignore-errors
- (insert-file-contents (locate-user-emacs-file "elpher-bookmarks"))
- (goto-char (point-min))
- (read (current-buffer)))))
+ (let ((bookmarks
+ (with-temp-buffer
+ (ignore-errors
+ (insert-file-contents (locate-user-emacs-file "elpher-bookmarks"))
+ (goto-char (point-min))
+ (read (current-buffer))))))
+ (if (and bookmarks (listp (cadar bookmarks)))
+ (progn
+ (message "Reading old bookmark file. (Will be updated on write.)")
+ (mapcar (lambda (old-bm)
+ (list (car old-bm)
+ (elpher-address-to-url (apply #'elpher-make-gopher-address
+ (cadr old-bm)))))
+ bookmarks))
+ bookmarks)))
(defun elpher-add-address-bookmark (address display-string)
- "Save a bookmark for ADDRESS with label DISPLAY-STRING.
+ "Save a bookmark for ADDRESS with label DISPLAY-STRING.)))
If ADDRESS is already bookmarked, update the label only."
- (let ((bookmarks (elpher-load-bookmarks)))
- (let ((existing-bookmark (rassoc (list address) bookmarks)))
+ (let ((bookmarks (elpher-load-bookmarks))
+ (url (elpher-address-to-url address)))
+ (let ((existing-bookmark (rassoc (list url) bookmarks)))
(if existing-bookmark
(elpher-set-bookmark-display-string existing-bookmark display-string)
- (add-to-list 'bookmarks (elpher-make-bookmark display-string address))))
+ (push (elpher-make-bookmark display-string url) bookmarks)))
(elpher-save-bookmarks bookmarks)))
(defun elpher-remove-address-bookmark (address)
"Remove any bookmark to ADDRESS."
+ (let ((url (elpher-address-to-url address)))
(elpher-save-bookmarks
(seq-filter (lambda (bookmark)
- (not (equal (elpher-bookmark-address bookmark) address)))
- (elpher-load-bookmarks))))
+ (not (equal (elpher-bookmark-url bookmark) url)))
+ (elpher-load-bookmarks)))))
;;; Interactive procedures
;;
(push-button))
(defun elpher-go ()
- "Go to a particular gopher site read from the minibuffer.
-The site may be specified via a URL or explicitly in terms of
-host, selector and port."
+ "Go to a particular gopher site read from the minibuffer."
(interactive)
(let ((node
- (let ((host-or-url (read-string "Gopher host or URL: ")))
- (if (string-match elpher-url-regex host-or-url)
- (elpher-make-node-from-matched-url host-or-url)
- (let ((selector (read-string "Selector (default none): " nil nil ""))
- (port-string (read-string "Port (default 70): " nil nil "70")))
- (elpher-make-node (concat "gopher://" host-or-url
- ":" port-string
- "/1" selector)
- (elpher-make-address ?1 selector host-or-url
- (string-to-number port-string))))))))
+ (let ((host-or-url (read-string "Gopher or Gemini URL: ")))
+ (elpher-make-node host-or-url
+ (elpher-address-from-url host-or-url)))))
(switch-to-buffer "*elpher*")
(elpher-visit-node node)))
-(defun elpher-redraw ()
+(defun elpher-go-current ()
+ "Go to a particular site read from the minibuffer, initialized with the current URL."
+ (interactive)
+ (let ((address (elpher-node-address elpher-current-node)))
+ (if (elpher-address-special-p address)
+ (error "Command invalid for this page")
+ (let ((url (read-string "Gopher or Gemini URL: " (elpher-address-to-url address))))
+ (elpher-visit-node (elpher-make-node url (elpher-address-from-url url)))))))
+
+(defun elpher-redraw ()
"Redraw current page."
(interactive)
(if elpher-current-node
(elpher-visit-node elpher-current-node)
(message "No current site.")))
-(defun elpher-reload ()
+(defun elpher-reload ()
"Reload current page."
(interactive)
(if elpher-current-node
(elpher-reload-current-node)
(message "No current site.")))
+(defun elpher-toggle-tls ()
+ "Toggle TLS encryption mode for gopher."
+ (interactive)
+ (setq elpher-use-tls (not elpher-use-tls))
+ (if elpher-use-tls
+ (if (gnutls-available-p)
+ (message "TLS gopher mode enabled. (Will not affect current page until reload.)")
+ (setq elpher-use-tls nil)
+ (error "Cannot enable TLS gopher mode: GnuTLS not available"))
+ (message "TLS gopher mode disabled. (Will not affect current page until reload.)")))
+
(defun elpher-view-raw ()
"View raw server response for current page."
(interactive)
(if (elpher-address-special-p (elpher-node-address elpher-current-node))
(error "This page was not generated by a server")
(elpher-visit-node elpher-current-node
- #'elpher-get-node-raw))
+ #'elpher-render-raw))
(message "No current site.")))
(defun elpher-back ()
(if button
(let ((node (button-get button 'elpher-node)))
(if (elpher-address-special-p (elpher-node-address node))
- (error "Cannot download this link")
+ (error "Cannot download %s"
+ (elpher-node-display-string node))
(elpher-visit-node (button-get button 'elpher-node)
- #'elpher-get-node-download)))
+ #'elpher-render-download)))
(error "No link selected"))))
+(defun elpher-download-current ()
+ "Download the current page."
+ (interactive)
+ (if (elpher-address-special-p (elpher-node-address elpher-current-node))
+ (error "Cannot download %s"
+ (elpher-node-display-string elpher-current-node))
+ (elpher-visit-node (elpher-make-node
+ (elpher-node-display-string elpher-current-node)
+ (elpher-node-address elpher-current-node)
+ elpher-current-node)
+ #'elpher-render-download
+ t)))
+
(defun elpher-build-link-map ()
"Build alist mapping link names to destination nodes in current buffer."
(let ((link-map nil)
(b (next-button (point-min) t)))
(while b
- (add-to-list 'link-map (cons (button-label b) b))
+ (push (cons (button-label b) b) link-map)
(setq b (next-button (button-start b))))
link-map))
(defun elpher-root-dir ()
"Visit root of current server."
(interactive)
- (let* ((address (elpher-node-address elpher-current-node))
- (host (elpher-address-host address)))
- (if host
- (let ((host (elpher-address-host address))
- (selector (elpher-address-selector address))
- (port (elpher-address-port address)))
- (if (> (length selector) 0)
- (let ((root-address (elpher-make-address ?1 "" host port)))
- (elpher-visit-node
- (elpher-make-node (concat "gopher://" host
- ":" (number-to-string port)
- "/1/")
- root-address)))
- (error "Already at root directory of current server")))
- (error "Command invalid for this page"))))
+ (let ((address (elpher-node-address elpher-current-node)))
+ (if (not (elpher-address-special-p address))
+ (if (or (member (url-filename address) '("/" ""))
+ (and (elpher-address-gopher-p address)
+ (= (length (elpher-gopher-address-selector address)) 0)))
+ (error "Already at root directory of current server")
+ (let ((address-copy (elpher-address-from-url
+ (elpher-address-to-url address))))
+ (setf (url-filename address-copy) "")
+ (elpher-visit-node
+ (elpher-make-node (elpher-address-to-url address-copy)
+ address-copy))))
+ (error "Command invalid for %s" (elpher-node-display-string elpher-current-node)))))
(defun elpher-bookmarks-current-p ()
"Return non-nil if current node is a bookmarks page."
- (eq (elpher-address-type (elpher-node-address elpher-current-node)) 'bookmarks))
+ (equal (elpher-address-type (elpher-node-address elpher-current-node))
+ '(special bookmarks)))
(defun elpher-reload-bookmarks ()
"Reload bookmarks if current node is a bookmarks page."
(defun elpher-bookmark-current ()
"Bookmark the current node."
(interactive)
- (unless (elpher-bookmarks-current-p)
- (let ((address (elpher-node-address elpher-current-node))
- (display-string (read-string "Bookmark display string: "
- (elpher-node-display-string elpher-current-node))))
- (elpher-add-address-bookmark address display-string)
- (message "Bookmark added."))))
+ (let ((address (elpher-node-address elpher-current-node))
+ (display-string (elpher-node-display-string elpher-current-node)))
+ (if (not (elpher-address-special-p address))
+ (let ((bookmark-display-string (read-string "Bookmark display string: "
+ display-string)))
+ (elpher-add-address-bookmark address bookmark-display-string)
+ (message "Bookmark added."))
+ (error "Cannot bookmark %s" display-string))))
(defun elpher-bookmark-link ()
"Bookmark the link at point."
(if button
(let* ((node (button-get button 'elpher-node))
(address (elpher-node-address node))
- (display-string (read-string "Bookmark display string: "
- (elpher-node-display-string node))))
- (elpher-add-address-bookmark address display-string)
- (elpher-reload-bookmarks)
- (message "Bookmark added."))
+ (display-string (elpher-node-display-string node)))
+ (if (not (elpher-address-special-p address))
+ (let ((bookmark-display-string (read-string "Bookmark display string: "
+ display-string)))
+ (elpher-add-address-bookmark address bookmark-display-string)
+ (elpher-reload-bookmarks)
+ (message "Bookmark added."))
+ (error "Cannot bookmark %s" display-string)))
(error "No link selected"))))
(defun elpher-unbookmark-current ()
"Remove bookmark for the current node."
(interactive)
- (unless (elpher-bookmarks-current-p)
- (elpher-remove-address-bookmark (elpher-node-address elpher-current-node))
- (message "Bookmark removed.")))
+ (let ((address (elpher-node-address elpher-current-node)))
+ (unless (elpher-address-special-p address)
+ (elpher-remove-address-bookmark address)
+ (message "Bookmark removed."))))
(defun elpher-unbookmark-link ()
"Remove bookmark for the link at point."
(error "No link selected"))))
(defun elpher-bookmarks ()
- "Visit bookmarks."
+ "Visit bookmarks page."
(interactive)
(switch-to-buffer "*elpher*")
(elpher-visit-node
- (elpher-make-node "Bookmarks" (elpher-make-address 'bookmarks))))
+ (elpher-make-node "Bookmarks Page" (elpher-make-special-address 'bookmarks))))
(defun elpher-info-node (node)
"Display information on NODE."
(let ((display-string (elpher-node-display-string node))
(address (elpher-node-address node)))
- (if address
- (message "`%s' on %s port %s"
- (elpher-address-selector address)
- (elpher-address-host address)
- (elpher-address-port address))
- (message "%s" display-string))))
+ (if (elpher-address-special-p address)
+ (message "Special page: %s" display-string)
+ (message "%s" (elpher-address-to-url address)))))
(defun elpher-info-link ()
"Display information on node corresponding to link at point."
(interactive)
(elpher-info-node elpher-current-node))
-(defun elpher-get-address-url (address)
- "Get URL representation of ADDRESS."
- (concat "gopher://"
- (elpher-address-host address)
- (let ((port (elpher-address-port address)))
- (if (equal port 70)
- ""
- (format ":%d" port)))
- "/" (string (elpher-address-type address))
- (elpher-address-selector address)))
-
(defun elpher-copy-node-url (node)
"Copy URL representation of address of NODE to `kill-ring'."
(let ((address (elpher-node-address node)))
- (if address
- (let ((url (elpher-get-address-url address)))
- (message url)
- (kill-new url))
- (error (format "Cannot represent %s as URL" (elpher-node-display-string node))))))
+ (if (elpher-address-special-p address)
+ (error (format "Cannot represent %s as URL" (elpher-node-display-string node)))
+ (let ((url (elpher-address-to-url address)))
+ (message "Copied \"%s\" to kill-ring/clipboard." url)
+ (kill-new url)))))
(defun elpher-copy-link-url ()
"Copy URL of item at point to `kill-ring'."
(interactive)
(elpher-copy-node-url elpher-current-node))
+(defun elpher-set-gopher-coding-system ()
+ "Specify an explicit character coding system for gopher selectors."
+ (interactive)
+ (let ((system (read-coding-system "Set coding system to use for gopher (default is to autodetect): " nil)))
+ (setq elpher-user-coding-system system)
+ (if system
+ (message "Gopher coding system fixed to %s. (Reload to see effect)." system)
+ (message "Gopher coding system set to autodetect. (Reload to see effect)."))))
+
+
;;; Mode and keymap
;;
(define-key map (kbd "TAB") 'elpher-next-link)
(define-key map (kbd "<backtab>") 'elpher-prev-link)
(define-key map (kbd "u") 'elpher-back)
+ (define-key map [mouse-3] 'elpher-back)
(define-key map (kbd "O") 'elpher-root-dir)
(define-key map (kbd "g") 'elpher-go)
+ (define-key map (kbd "o") 'elpher-go-current)
(define-key map (kbd "r") 'elpher-redraw)
(define-key map (kbd "R") 'elpher-reload)
- (define-key map (kbd "w") 'elpher-view-raw)
+ (define-key map (kbd "T") 'elpher-toggle-tls)
+ (define-key map (kbd ".") 'elpher-view-raw)
(define-key map (kbd "d") 'elpher-download)
+ (define-key map (kbd "D") 'elpher-download-current)
(define-key map (kbd "m") 'elpher-jump)
(define-key map (kbd "i") 'elpher-info-link)
(define-key map (kbd "I") 'elpher-info-current)
(define-key map (kbd "x") 'elpher-unbookmark-link)
(define-key map (kbd "X") 'elpher-unbookmark-current)
(define-key map (kbd "B") 'elpher-bookmarks)
- (when (fboundp 'evil-define-key)
- (evil-define-key 'motion map
+ (define-key map (kbd "S") 'elpher-set-gopher-coding-system)
+ (when (fboundp 'evil-define-key*)
+ (evil-define-key* 'motion map
(kbd "TAB") 'elpher-next-link
- (kbd "C-]") 'elpher-follow-current-link
+ (kbd "C-") 'elpher-follow-current-link
(kbd "C-t") 'elpher-back
(kbd "u") 'elpher-back
- (kbd "O") 'elpher-root-dir
+ [mouse-3] 'elpher-back
(kbd "g") 'elpher-go
+ (kbd "o") 'elpher-go-current
(kbd "r") 'elpher-redraw
(kbd "R") 'elpher-reload
- (kbd "w") 'elpher-view-raw
+ (kbd "T") 'elpher-toggle-tls
+ (kbd ".") 'elpher-view-raw
(kbd "d") 'elpher-download
+ (kbd "D") 'elpher-download-current
(kbd "m") 'elpher-jump
(kbd "i") 'elpher-info-link
(kbd "I") 'elpher-info-current
(kbd "A") 'elpher-bookmark-current
(kbd "x") 'elpher-unbookmark-link
(kbd "X") 'elpher-unbookmark-current
- (kbd "B") 'elpher-bookmarks))
+ (kbd "B") 'elpher-bookmarks
+ (kbd "S") 'elpher-set-gopher-coding-system))
map)
"Keymap for gopher client.")
(define-derived-mode elpher-mode special-mode "elpher"
- "Major mode for elpher, an elisp gopher client.")
+ "Major mode for elpher, an elisp gopher client.
+
+This mode is automatically enabled by the interactive
+functions which initialize the gopher client, namely
+`elpher', `elpher-go' and `elpher-bookmarks'.")
(when (fboundp 'evil-set-initial-state)
(evil-set-initial-state 'elpher-mode 'motion))
+
;;; Main start procedure
;;
(switch-to-buffer "*elpher*")
(setq elpher-current-node nil)
(let ((start-node (elpher-make-node "Elpher Start Page"
- (elpher-make-address 'start))))
+ (elpher-make-special-address 'start))))
(elpher-visit-node start-node)))
"Started Elpher.") ; Otherwise (elpher) evaluates to start page string.
The Lambda Lab / projects / elpher.git / blobdiff