-;;; elpher.el --- Full-featured gopher client.
+;;; elpher.el --- A friendly gopher client.
;; Copyright (C) 2019 Tim Vaughan
;; Author: Tim Vaughan <tgvaughan@gmail.com>
;; Created: 11 April 2019
-;; Version: 1.2.0
+;; Version: 1.2.4
;; Keywords: comm gopher
;; Homepage: https://github.com/tgvaughan/elpher
;; Package-Requires: ((emacs "25"))
;;; Commentary:
-;; Elpher aims to provide a full-featured gopher client for GNU Emacs.
+;; Elpher aims to provide a practical gopher client for GNU Emacs.
;; It supports:
;; - intuitive keyboard and mouse-driven interface,
;; - 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.
+;; - 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.
;; page containing information on key bindings and suggested starting
;; points for your gopher exploration.
-;; Faces, caching options and start page can be configured via
+;; Faces, caching and other options can be configured via
;; the Elpher customization group in Applications.
;;; Code:
(provide 'elpher)
(require 'seq)
(require 'pp)
+(require 'shr)
;;; Global constants
;;
-(defconst elpher-version "1.2.0"
+(defconst elpher-version "1.2.4"
"Current version of elpher.")
(defconst elpher-margin-width 6
"Source for elpher start page.")
(defconst elpher-type-map
- '((?0 elpher-get-text-node "T" elpher-text)
+ '((?0 elpher-get-text-node "txt" 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)
+ (?4 elpher-get-node-download "bin" elpher-binary)
+ (?5 elpher-get-node-download "bin" 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)
- (?h elpher-get-url-node "W" elpher-url)
+ (?8 elpher-get-telnet-node "tel" elpher-telnet)
+ (?9 elpher-get-node-download "bin" elpher-binary)
+ (?g elpher-get-image-node "img" elpher-image)
+ (?p elpher-get-image-node "img" elpher-image)
+ (?I elpher-get-image-node "img" elpher-image)
+ (?d elpher-get-node-download "doc" elpher-binary)
+ (?h elpher-get-url-node "web" 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.")
"Retrieve port from ADDRESS."
(elt address 3))
+(defun elpher-address-special-p (address)
+ "Return non-nil if ADDRESS is special (e.g. start page, bookmarks page)."
+ (not (elpher-address-host address)))
+
;; Node
-(defun elpher-make-node (display-string parent address)
+(defun elpher-make-node (display-string address &optional parent)
"Create a node in the gopher page hierarchy.
DISPLAY-STRING records the display string used for the page.
-PARENT specifies the parent of the node, and ADDRESS specifies the
-address of the gopher page."
- (list display-string parent address))
+ADDRESS specifies the address of the gopher page.
+
+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-parent (node)
- "Retrieve the parent node of NODE."
- (elt node 1))
-
(defun elpher-node-address (node)
"Retrieve the address of NODE."
+ (elt node 1))
+
+(defun elpher-node-parent (node)
+ "Retrieve the parent node of NODE."
(elt node 2))
+(defun elpher-set-node-parent (node parent)
+ "Set the parent node of NODE to be PARENT."
+ (setcar (cdr (cdr node)) parent))
+
;; Cache
(defvar elpher-content-cache (make-hash-table :test 'equal))
(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 getter preserve-parent)
+ "Visit NODE using its own getter or GETTER, 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)
"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."
;;; Index rendering
;;
+(defun elpher-decode (string)
+ "Return decoded STRING."
+ (let ((coding (detect-coding-string string t)))
+ (decode-coding-string string coding)))
+
(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)))
+ (elpher-decode string))))
(defun elpher-insert-index (string)
"Insert the index corresponding to STRING into the current buffer."
(elpher-address-host address)
(elpher-address-port address)))))
+
(defun elpher-insert-index-record (display-string type selector host port)
"Function to insert an index record into the current buffer.
The contents of the record are dictated by TYPE, DISPLAY-STRING, SELECTOR, HOST
(let ((address (elpher-make-address type selector host port))
(type-map-entry (alist-get type elpher-type-map)))
(if type-map-entry
- (let* ((margin-code (cadr type-map-entry))
+ (let* ((margin-code (elt type-map-entry 1))
(face (elt type-map-entry 2))
- (node (elpher-make-node display-string elpher-current-node address)))
+ (node (elpher-make-node display-string address)))
(elpher-insert-margin margin-code)
(insert-text-button display-string
'face face
(other ;; Unknown
(elpher-insert-margin (concat (char-to-string type) "?"))
(insert (propertize display-string
- 'face 'elpher-unknown-face)))))
+ 'face 'elpher-unknown)))))
(insert "\n")))
(defun elpher-click-link (button)
"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")))
+ (condition-case nil
+ (progn
+ (make-network-process :name "elpher-process"
+ :host (elpher-address-host address)
+ :service (elpher-address-port address)
+ :coding 'no-conversion
+ :filter-multibyte nil
+ :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
(insert content)
(elpher-restore-pos)))
(elpher-with-clean-buffer
- (insert "LOADING DIRECTORY..."))
+ (insert "LOADING DIRECTORY... (use 'u' to cancel)"))
(elpher-get-selector address
(lambda (proc event)
(unless (string-prefix-p "deleted" event)
"\\([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 (parent &optional string)
+(defun elpher-make-node-from-matched-url (&optional string)
"Convert most recent `elpher-url-regex' match to a node.
-PARENT defines the node to set as the parent to the new 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))
(substring type-and-selector 2)
""))
(address (elpher-make-address type selector host port)))
- (elpher-make-node url elpher-current-node address))
+ (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 elpher-current-node address)))))
+ (elpher-make-node url address)))))
(defun elpher-buttonify-urls (string)
(insert string)
(goto-char (point-min))
(while (re-search-forward elpher-url-regex nil t)
- (let ((node (elpher-make-node-from-matched-url elpher-current-node)))
+ (let ((node (elpher-make-node-from-matched-url)))
(make-text-button (match-beginning 0)
(match-end 0)
'elpher-node node
(elpher-restore-pos)))
(progn
(elpher-with-clean-buffer
- (insert "LOADING TEXT..."))
+ (insert "LOADING TEXT... (use 'u' to cancel)"))
(elpher-get-selector address
(lambda (proc event)
(unless (string-prefix-p "deleted" event)
(if (display-images-p)
(progn
(elpher-with-clean-buffer
- (insert "LOADING IMAGE..."))
+ (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)
+ elpher-selector-string
nil t)))
(elpher-with-clean-buffer
(insert-image image)
(elpher-address-port address))))
(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)
"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..."))
+ (insert "LOADING RAW SERVER RESPONSE... (use 'u' to cancel)"))
(if address
(elpher-get-selector address
(lambda (proc event)
;; 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."
(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 ((url (elt (split-string selector "URL:") 1)))
- (if elpher-open-urls-with-eww
- (browse-web url)
- (browse-url url)))))
+ (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)))
+ (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))))))))))))
;; Telnet node connection
;; Bookmarks page node retrieval
(defun elpher-get-bookmarks-node ()
- "Getter which loads and displays the current bookmark list."
+ "Getter to load and display the current bookmark list."
(elpher-with-clean-buffer
(insert "---- Bookmark list ----\n\n")
(let ((bookmarks (elpher-load-bookmarks)))
(elpher-address-port 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")
+ "- 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)))
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")
(pp bookmarks (current-buffer))))
(defun elpher-load-bookmarks ()
(push-button))
(defun elpher-go ()
- "Go to a particular gopher site."
+ "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."
(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 elpher-current-node
- 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-current-node
(elpher-make-address ?1 selector host-or-url
(string-to-number port-string))))))))
(switch-to-buffer "*elpher*")
(message "No current site.")))
(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-get-node-raw))
(message "No current site.")))
(defun elpher-back ()
(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)
- (error "Can only download gopher links, not general URLs")))
+ (if (elpher-address-special-p (elpher-node-address node))
+ (error "Cannot download this link")
+ (elpher-visit-node (button-get button 'elpher-node)
+ #'elpher-get-node-download)))
(error "No link selected"))))
(defun elpher-build-link-map ()
(let* ((link-map (elpher-build-link-map)))
(if link-map
(let ((key (let ((completion-ignore-case t))
- (completing-read "Directory entry/link (tab to autocomplete): "
+ (completing-read "Directory item/link: "
link-map nil t))))
(if (and key (> (length key) 0))
(let ((b (cdr (assoc key link-map))))
(elpher-make-node (concat "gopher://" host
":" (number-to-string port)
"/1/")
- elpher-current-node
root-address)))
(error "Already at root directory of current server")))
(error "Command invalid for this 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."
(defun elpher-bookmarks ()
"Visit bookmarks."
(interactive)
+ (switch-to-buffer "*elpher*")
(elpher-visit-node
- (elpher-make-node "Bookmarks"
- elpher-current-node
- (elpher-make-address 'bookmarks))))
+ (elpher-make-node "Bookmarks Page" (elpher-make-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
+ (if (not (elpher-address-special-p address))
(message "`%s' on %s port %s"
(elpher-address-selector address)
(elpher-address-host address)
(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)))
+ (let ((type (elpher-address-type address))
+ (selector (elpher-address-selector address))
+ (host (elpher-address-host address))
+ (port (elpher-address-port address)))
+ (if (and (equal type ?h)
+ (string-prefix-p "URL:" selector))
+ (elt (split-string selector "URL:") 1)
+ (concat "gopher://"
+ host
+ (if (equal port 70)
+ ""
+ (format ":%d" port))
+ "/" (string type)
+ selector))))
(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-get-address-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'."
(switch-to-buffer "*elpher*")
(switch-to-buffer "*elpher*")
(setq elpher-current-node nil)
- (let ((start-node (elpher-make-node "Elpher Start Page" nil (elpher-make-address 'start))))
+ (let ((start-node (elpher-make-node "Elpher Start Page"
+ (elpher-make-address 'start))))
(elpher-visit-node start-node)))
"Started Elpher.") ; Otherwise (elpher) evaluates to start page string.