-;;; elpher.el --- Full-featured 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: 1.1.1
+;; Version: 2.2.0
;; 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 full-featured 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 browsing,
-;; - caching of visited sites (both content and cursor position),
+;; - 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.
-
-;; 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 options and start page 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 "1.1.1"
+(defconst elpher-version "2.2.0"
"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 directory entry on current page\tfake\tfake\t1"
- "i - RET/mouse-1: open directory entry under cursor\tfake\tfake\t1"
- "i - m: select a directory entry by name (autocompletes)\tfake\tfake\t1"
- "i - u: return to parent directory entry\tfake\tfake\t1"
- "i - O: visit the root directory of the current server\tfake\tfake\t1"
- "i - g: go to a particular 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"
- "iPlaces 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)
- (?g elpher-get-image-node "im" elpher-image)
- (?p elpher-get-image-node "im" elpher-image)
- (?I elpher-get-image-node "im" elpher-image)
- (?4 elpher-get-node-download "B" elpher-binary)
- (?5 elpher-get-node-download "B" elpher-binary)
- (?9 elpher-get-node-download "B" elpher-binary)
- (?7 elpher-get-search-node "?" elpher-search))
- "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
;; Face customizations
(defface elpher-index
- '((t :inherit org-drawer))
+ '((t :inherit font-lock-keyword-face))
"Face used for directory type directory records.")
(defface elpher-text
- '((t :inherit org-tag))
+ '((t :inherit bold))
"Face used for text type directory records.")
(defface elpher-info
- '((t :inherit org-default))
+ '((t :inherit default))
"Face used for info type directory records.")
(defface elpher-image
- '((t :inherit org-level-4))
+ '((t :inherit font-lock-string-face))
"Face used for image type directory records.")
(defface elpher-search
- '((t :inherit org-level-5))
+ '((t :inherit warning))
"Face used for search type directory records.")
-(defface elpher-url
- '((t :inherit org-level-6))
- "Face used for url type directory records.")
+(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 other URL type links records.")
+
+(defface elpher-telnet
+ '((t :inherit font-lock-function-name-face))
+ "Face used for telnet type directory records.")
(defface elpher-binary
- '((t :inherit org-level-7))
+ '((t :inherit font-lock-doc-face))
"Face used for binary type directory records.")
(defface elpher-unknown
- '((t :inherit org-warning))
+ '((t :inherit error))
"Face used for directory records with unknown/unsupported types.")
(defface elpher-margin-key
- '((t :inherit org-tag))
+ '((t :inherit bold))
"Face used for directory margin key.")
(defface elpher-margin-brackets
- '((t :inherit org-special-keyword))
+ '((t :inherit shadow))
"Face used for brackets around directory margin key.")
;; Other customizations
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."
+(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))
-(defcustom elpher-start-address nil
- "If nil, the default start directory is shown when Elpher is started.
-Otherwise, a list containing the selector, host and port of a directory to
-use as the start page."
- :type '(list string string integer))
;;; Model
;;
;; Address
-(defun elpher-make-address (selector host port)
- "Create an address of a gopher object with SELECTOR, HOST and PORT."
- (list selector host port))
-
-(defun elpher-address-selector (address)
- "Retrieve selector from ADDRESS."
- (elt address 0))
+;; 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 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 1))
+ "Retrieve host from ADDRESS object."
+ (url-host address))
(defun elpher-address-port (address)
- "Retrieve port from ADDRESS."
- (elt address 2))
+ "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 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 (parent address getter &optional content pos)
- "Create a node in the gopher page hierarchy.
+(defun elpher-make-node (display-string address &optional parent)
+ "Create a node in the page hierarchy.
-PARENT specifies the parent of the node, ADDRESS specifies the address of
-the gopher page, GETTER provides the getter function used to obtain this
-page.
+DISPLAY-STRING records the display string used for the page.
-The optional arguments CONTENT and POS can be used to fill the cached
-content and cursor position fields of the node."
- (list parent address getter content pos))
+ADDRESS specifies the address object of the page.
-(defun elpher-node-parent (node)
- "Retrieve the parent node of NODE."
+The optional PARENT specifies the parent node in the hierarchy.
+This is set every time the node is visited, so while it forms
+an important part of the node data there is no need to set it
+initially."
+ (list display-string address parent))
+
+(defun elpher-node-display-string (node)
+ "Retrieve the display string of NODE."
(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-getter (node)
- "Retrieve the preferred getter function of NODE."
+(defun elpher-node-parent (node)
+ "Retrieve the parent node of NODE."
(elt node 2))
-(defun elpher-node-content (node)
- "Retrieve the cached content of NODE, or nil if none exists."
- (elt node 3))
+(defun elpher-set-node-parent (node parent)
+ "Set the parent node of NODE to be PARENT."
+ (setcar (cdr (cdr node)) parent))
-(defun elpher-node-pos (node)
- "Retrieve the cached cursor position for NODE, or nil if none exists."
- (elt node 4))
+;; Cache
-(defun elpher-set-node-content (node content)
- "Set the content cache of NODE to CONTENT."
- (setcar (nthcdr 3 node) content))
+(defvar elpher-content-cache (make-hash-table :test 'equal))
+(defvar elpher-pos-cache (make-hash-table :test 'equal))
-(defun elpher-set-node-pos (node pos)
- "Set the cursor position cache of NODE to POS."
- (setcar (nthcdr 4 node) pos))
+(defun elpher-get-cached-content (address)
+ "Retrieve the cached content for ADDRESS, or nil if none exists."
+ (gethash address elpher-content-cache))
+
+(defun elpher-cache-content (address content)
+ "Set the content cache for ADDRESS to CONTENT."
+ (puthash address content elpher-content-cache))
+
+(defun elpher-get-cached-pos (address)
+ "Retrieve the cached cursor position for ADDRESS, or nil if none exists."
+ (gethash address elpher-pos-cache))
+
+(defun elpher-cache-pos (address pos)
+ "Set the cursor position cache for ADDRESS to POS."
+ (puthash address pos elpher-pos-cache))
;; Node graph traversal
(defvar elpher-current-node nil)
-(defun elpher-visit-node (node &optional getter)
- "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-process-cleanup)
+ (unless preserve-parent
+ (if (and (elpher-node-parent elpher-current-node)
+ (equal (elpher-node-address elpher-current-node)
+ (elpher-node-address node)))
+ (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)
- (funcall (elpher-node-getter node))))
+ (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."
(let ((parent-node (elpher-node-parent elpher-current-node)))
(when parent-node
- (elpher-visit-node parent-node))))
+ (elpher-visit-node parent-node nil t))))
(defun elpher-reload-current-node ()
"Reload the current node, discarding any existing cached content."
- (elpher-set-node-content elpher-current-node nil)
+ (elpher-cache-content (elpher-node-address elpher-current-node) nil)
(elpher-visit-node elpher-current-node))
(defun elpher-save-pos ()
"Save the current position of point to the current node."
(when elpher-current-node
- (elpher-set-node-pos elpher-current-node (point))))
+ (elpher-cache-pos (elpher-node-address elpher-current-node) (point))))
(defun elpher-restore-pos ()
"Restore the position of point to that cached in the current node."
- (let ((pos (elpher-node-pos elpher-current-node)))
+ (let ((pos (elpher-get-cached-pos (elpher-node-address elpher-current-node))))
(if pos
(goto-char pos)
(goto-char (point-min)))))
+
;;; Buffer preparation
;;
+(defun elpher-update-header ()
+ "If `elpher-use-header' is true, display current node info in window header."
+ (if elpher-use-header
+ (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) ""))))
+ (setq header-line-format (list display-string url-string)))))
+
(defmacro elpher-with-clean-buffer (&rest args)
"Evaluate ARGS with a clean *elpher* buffer as current."
(list 'with-current-buffer "*elpher*"
'(elpher-mode)
(append (list 'let '((inhibit-read-only t))
- '(erase-buffer))
+ '(erase-buffer)
+ '(elpher-update-header))
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)
+ "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)
+ (process-send-string proc
+ (concat (elpher-gopher-address-selector address) "\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."
;; Should be able to split directly on CRLF, but some non-conformant
;; LF-only servers sadly exist, hence the following.
- (let* ((str-no-period (replace-regexp-in-string "\r\n\.\r\n$" "\r\n" string))
- (str-no-cr (replace-regexp-in-string "\r" "" str-no-period)))
- (dolist (line (split-string str-no-cr "\n"))
- (unless (= (length line) 0)
- (elpher-insert-index-record line)))))
+ (let ((str-processed (elpher-preprocess-text-response string)))
+ (dolist (line (split-string str-processed "\n"))
+ (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."
(insert " "))
(insert (make-string elpher-margin-width ?\s))))
-(defun elpher-insert-index-record (line)
- "Insert the index record corresponding to LINE into the current buffer."
- (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 (elt fields 3))
- (address (elpher-make-address selector host port))
- (type-map-entry (alist-get type elpher-type-map)))
+(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)))
+ (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 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 ((getter (car type-map-entry))
- (margin-code (cadr type-map-entry))
- (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
'face face
- 'elpher-node (elpher-make-node elpher-current-node
- address
- getter)
+ 'elpher-node node
'action #'elpher-click-link
'follow-link t
- 'help-echo (format "mouse-1, RET: open '%s' on %s port %s"
- selector host port)))
+ 'help-echo (elpher-node-button-help node)))
(pcase type
- (?i (elpher-insert-margin) ;; Information
- (insert (propertize
- (if elpher-buttonify-urls-in-directories
- (elpher-buttonify-urls display-string)
- display-string)
- 'face 'elpher-info)))
- (?h (elpher-insert-margin "W") ;; Web link
- (let ((url (elt (split-string selector "URL:") 1)))
- (insert-text-button display-string
- 'face 'elpher-url
- 'elpher-url url
- 'action #'elpher-click-url
- 'follow-link t
- 'help-echo (format "mouse-1, RET: open url %s" url))))
- (tp (elpher-insert-margin (concat (char-to-string tp) "?"))
- (insert (propertize display-string
- 'face 'elpher-unknown-face)))))
+ ((or '(gopher ?i) 'nil) ;; Information
+ (elpher-insert-margin)
+ (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")))
+(defun elpher-click-link (button)
+ "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
+ (let ((node (button-get button 'elpher-node)))
+ (elpher-visit-node node)))
-;;; Selector retrieval (all kinds)
-;;
+(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)))))
-(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 "")
- (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")))
-
-;; Index retrieval
-
-(defun elpher-get-index-node ()
- "Getter which retrieves the current node contents as an index."
- (let ((content (elpher-node-content elpher-current-node))
- (address (elpher-node-address elpher-current-node)))
- (if content
- (progn
- (elpher-with-clean-buffer
- (insert content)
- (elpher-restore-pos)))
- (if address
- (progn
- (elpher-with-clean-buffer
- (insert "LOADING DIRECTORY..."))
- (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-set-node-content elpher-current-node
- (buffer-string)))))))
- (progn
- (elpher-with-clean-buffer
- (elpher-insert-index elpher-start-index)
- (elpher-restore-pos)
- (elpher-set-node-content elpher-current-node
- (buffer-string))))))))
-
-;; Text retrieval
+;; Text rendering
(defconst elpher-url-regex
- "\\(https?\\|gopher\\)://\\([a-zA-Z0-9.\-]+\\)\\(?3::[0-9]+\\)?\\(?4:/[^ \r\n\t(),]*\\)?"
- "Regexp used to locate and buttinofy URLs in text files loaded by elpher.")
+ "\\([a-zA-Z]+\\)://\\([a-zA-Z0-9.\-]+\\|\[[a-zA-Z0-9:]+\]\\)\\(?3::[0-9]+\\)?\\(?4:/[^<> \r\n\t(),]*\\)?"
+ "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 ((url (match-string 0))
- (protocol (downcase (match-string 1))))
- (if (string= protocol "gopher")
- (let* ((host (match-string 2))
- (port (if (match-string 3)
- (string-to-number (substring (match-string 3) 1))
- 70))
- (type-and-selector (match-string 4))
- (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 selector host port))
- (getter (car (alist-get type elpher-type-map))))
- (make-text-button (match-beginning 0)
- (match-end 0)
- 'elpher-node (elpher-make-node elpher-current-node
- address
- getter)
- 'action #'elpher-click-link
- 'follow-link t
- 'help-echo (format "mouse-1, RET: open '%s' on %s port %s"
- selector host port)))
+ (let ((node (elpher-make-node (match-string 0)
+ (elpher-address-from-url (match-string 0)))))
(make-text-button (match-beginning 0)
(match-end 0)
- 'elpher-url url
- 'action #'elpher-click-url
+ 'elpher-node node
+ 'action #'elpher-click-link
'follow-link t
- 'help-echo (format "mouse-1, RET: open url %s" url)))))
+ 'help-echo (elpher-node-button-help node)
+ 'face 'button)))
(buffer-string)))
-(defun elpher-process-text (string)
- "Remove CRs and trailing period from the gopher text document STRING."
- (let* ((chopped-str (replace-regexp-in-string "\r\n\.\r\n$" "\r\n" string))
- (cleaned-str (replace-regexp-in-string "\r" "" chopped-str)))
- (elpher-buttonify-urls cleaned-str)))
-
-(defun elpher-get-text-node ()
- "Getter which retrieves the current node contents as a text document."
- (let ((content (elpher-node-content elpher-current-node))
- (address (elpher-node-address elpher-current-node)))
- (if content
- (progn
- (elpher-with-clean-buffer
- (insert content)
- (elpher-restore-pos)))
- (progn
- (elpher-with-clean-buffer
- (insert "LOADING TEXT..."))
- (elpher-get-selector address
- (lambda (proc event)
- (unless (string-prefix-p "deleted" event)
- (elpher-with-clean-buffer
- (insert (elpher-process-text elpher-selector-string))
- (elpher-restore-pos)
- (elpher-set-node-content 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 ((content (elpher-node-content elpher-current-node))
- (address (elpher-node-address elpher-current-node)))
- (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..."))
- (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-set-node-content 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 ((content (elpher-node-content elpher-current-node))
- (address (elpher-node-address elpher-current-node))
- (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 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..."))
+ (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-set-node-content 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* ((content (elpher-node-content elpher-current-node))
- (address (elpher-node-address elpher-current-node)))
- (elpher-with-clean-buffer
- (insert "LOADING RAW SERVER RESPONSE..."))
- (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
-
-(defvar elpher-download-filename)
+;; Raw server response rendering
-(defun elpher-get-node-download ()
- "Getter which retrieves the current node and writes the result to a file."
+(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 retrieve TLS selector: GnuTLS not available")
+ (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)
+ (process-send-string proc
+ (concat (elpher-address-to-url address) "\r\n")))))
+
+
+(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-header (car (split-string elpher-gemini-response "\r\n")))
+ (response-body (substring elpher-gemini-response
+ (+ (string-match "\r\n" elpher-gemini-response) 2)))
+ (response-code (car (split-string response-header)))
+ (response-meta (string-trim
+ (substring response-header
+ (string-match "[ \t]+" response-header)))))
+ (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"))
+ (?5 ; Permanent failure
+ (error "Gemini server reports PERMANENT FAILURE for this request"))
+ (?6 ; Client certificate required
+ (error "Gemini server requires client certificate (unsupported at this time)"))
+ (_other
+ (error "Gemini server responded with unknown response code %S"
+ response-code))))
+ (error
+ (elpher-network-error (elpher-node-address elpher-current-node) the-error))))
+
+(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)))
- (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)))))))))
-
+ (content (elpher-get-cached-content address)))
+ (condition-case the-error
+ (if (and content (funcall renderer nil))
+ (elpher-with-clean-buffer
+ (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))))
+ (if (and (equal "text/gemini" mime-type)
+ (not (assoc "charset" parameters)))
+ (setq parameters (cons (list "charset" "utf-8") parameters)))
+ (when (string-prefix-p "text/" mime-type)
+ (if (assoc "charset" parameters)
+ (setq body (decode-coding-string body
+ (intern (cadr (assoc "charset" parameters))))))
+ (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-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")))
+ 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 (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)))
+ (elpher-visit-parent-node)
+ (telnet host port)))
+
+;; Start page node retrieval
+
+(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
+ (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: 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 (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-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"
+ "- x: delete selected bookmark\n"
+ "- a: rename selected bookmark\n\n"
+ "Bookmarks are stored in the file "
+ (locate-user-emacs-file "elpher-bookmarks"))
+ (elpher-restore-pos)))
+
+
+;;; Bookmarks
+;;
-;;; Navigation procedures
+(defun elpher-make-bookmark (display-string url)
+ "Make an elpher bookmark.
+DISPLAY-STRING determines how the bookmark will appear in the
+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."
+ (elt bookmark 0))
+
+(defun elpher-set-bookmark-display-string (bookmark display-string)
+ "Set the display string of BOOKMARK to DISPLAY-STRING."
+ (setcar bookmark display-string))
+
+(defun elpher-bookmark-url (bookmark)
+ "Get the address for BOOKMARK."
+ (elt bookmark 1))
+
+(defun elpher-save-bookmarks (bookmarks)
+ "Record the bookmark list BOOKMARKS to the user's bookmark file.
+Beware that this completely replaces the existing contents of the file."
+ (with-temp-file (locate-user-emacs-file "elpher-bookmarks")
+ (erase-buffer)
+ (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."
+ (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.)))
+If ADDRESS is already bookmarked, update the label only."
+ (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)
+ (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-url bookmark) url)))
+ (elpher-load-bookmarks)))))
+
+;;; Interactive procedures
;;
(defun elpher-next-link ()
(interactive)
(backward-button 1))
-(defun elpher-click-link (button)
- "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
- (let ((node (button-get button 'elpher-node)))
- (elpher-visit-node node)))
-
-(defun elpher-click-url (button)
- "Function called when the url link BUTTON is activated (via mouse or keypress)."
- (let ((url (button-get button 'elpher-url)))
- (if elpher-open-urls-with-eww
- (browse-web url)
- (browse-url url))))
-
(defun elpher-follow-current-link ()
"Open the link or url at point."
(interactive)
(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)
- (if (not (string= (downcase (match-string 1 host-or-url)) "gopher"))
- (error "Only gopher URLs acceptable")
- (let* ((host (match-string 2 host-or-url))
- (port (if (match-string 3 host-or-url)
- (string-to-number (substring (match-string 3 host-or-url) 1))
- 70))
- (type-and-selector (match-string 4 host-or-url))
- (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 selector host port))
- (getter (car (alist-get type elpher-type-map))))
- (elpher-make-node elpher-current-node
- address
- getter)))
- (let* ((selector (read-string "Selector (default none): " nil nil ""))
- (port (read-string "Port (default 70): " nil nil 70))
- (address (list selector host-or-url port)))
- (elpher-make-node elpher-current-node
- address
- #'elpher-get-index-node))))))
+ (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."
+ (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 current page as plain text."
+ "View raw server response for current page."
(interactive)
(if elpher-current-node
- (elpher-visit-node elpher-current-node
- #'elpher-get-node-raw)
+ (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-render-raw))
(message "No current site.")))
(defun elpher-back ()
(interactive)
(if (elpher-node-parent elpher-current-node)
(elpher-visit-parent-node)
- (message "No previous site.")))
+ (error "No previous site")))
(defun elpher-download ()
"Download the link at point."
(let ((button (button-at (point))))
(if button
(let ((node (button-get button 'elpher-node)))
- (if node
- (elpher-visit-node (button-get button 'elpher-node)
- #'elpher-get-node-download)
- (message "Can only download gopher links, not general URLs.")))
- (message "No link selected."))))
+ (if (elpher-address-special-p (elpher-node-address node))
+ (error "Cannot download %s"
+ (elpher-node-display-string node))
+ (elpher-visit-node (button-get button 'elpher-node)
+ #'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-menu ()
+(defun elpher-jump ()
"Select a directory entry by name. Similar to the info browser (m)enu command."
(interactive)
(let* ((link-map (elpher-build-link-map)))
"Visit root of current server."
(interactive)
(let ((address (elpher-node-address elpher-current-node)))
- (if address
- (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 "" host port)))
- (elpher-visit-node (elpher-make-node elpher-current-node
- root-address
- #'elpher-get-index-node)))
- (message "Already at root directory of current server.")))
- (message "Command invalid for Elpher start page."))))
+ (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."
+ (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."
+ (if (elpher-bookmarks-current-p)
+ (elpher-reload-current-node)))
+
+(defun elpher-bookmark-current ()
+ "Bookmark the current node."
+ (interactive)
+ (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."
+ (interactive)
+ (let ((button (button-at (point))))
+ (if button
+ (let* ((node (button-get button 'elpher-node))
+ (address (elpher-node-address node))
+ (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)
+ (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."
+ (interactive)
+ (let ((button (button-at (point))))
+ (if button
+ (let ((node (button-get button 'elpher-node)))
+ (elpher-remove-address-bookmark (elpher-node-address node))
+ (elpher-reload-bookmarks)
+ (message "Bookmark removed."))
+ (error "No link selected"))))
+
+(defun elpher-bookmarks ()
+ "Visit bookmarks page."
+ (interactive)
+ (switch-to-buffer "*elpher*")
+ (elpher-visit-node
+ (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 (elpher-address-special-p address)
+ (message "Special page: %s" display-string)
+ (message (elpher-address-to-url address)))))
+
+(defun elpher-info-link ()
+ "Display information on node corresponding to link at point."
+ (interactive)
+ (let ((button (button-at (point))))
+ (if button
+ (elpher-info-node (button-get button 'elpher-node))
+ (error "No item selected"))))
+
+(defun elpher-info-current ()
+ "Display information on current node."
+ (interactive)
+ (elpher-info-node elpher-current-node))
+
+(defun elpher-copy-node-url (node)
+ "Copy URL representation of address of NODE to `kill-ring'."
+ (let ((address (elpher-node-address 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)
+ (let ((button (button-at (point))))
+ (if button
+ (elpher-copy-node-url (button-get button 'elpher-node))
+ (error "No item selected"))))
+
+(defun elpher-copy-current-url ()
+ "Copy URL of current node 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 "m") 'elpher-menu)
- (when (fboundp 'evil-define-key)
- (evil-define-key 'normal map
+ (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 "c") 'elpher-copy-link-url)
+ (define-key map (kbd "C") 'elpher-copy-current-url)
+ (define-key map (kbd "a") 'elpher-bookmark-link)
+ (define-key map (kbd "A") 'elpher-bookmark-current)
+ (define-key map (kbd "x") 'elpher-unbookmark-link)
+ (define-key map (kbd "X") 'elpher-unbookmark-current)
+ (define-key map (kbd "B") 'elpher-bookmarks)
+ (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 "m") 'elpher-menu))
+ (kbd "D") 'elpher-download-current
+ (kbd "m") 'elpher-jump
+ (kbd "i") 'elpher-info-link
+ (kbd "I") 'elpher-info-current
+ (kbd "c") 'elpher-copy-link-url
+ (kbd "C") 'elpher-copy-current-url
+ (kbd "a") 'elpher-bookmark-link
+ (kbd "A") 'elpher-bookmark-current
+ (kbd "x") 'elpher-unbookmark-link
+ (kbd "X") 'elpher-unbookmark-current
+ (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*")
(switch-to-buffer "*elpher*")
(setq elpher-current-node nil)
- (let ((start-node (elpher-make-node nil
- elpher-start-address
- #'elpher-get-index-node)))
+ (let ((start-node (elpher-make-node "Elpher Start Page"
+ (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