lisp/gnus/nnweb.el

   1 ;;; nnweb.el --- retrieving articles via web search engines
   2 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
   3 ;;        Free Software Foundation, Inc.
   4
   5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   6 ;; Keywords: news
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; Note: You need to have `w3' installed for some functions to work.
  28
  29 ;;; Code:
  30
  31 (eval-when-compile (require 'cl))
  32
  33 (require 'nnoo)
  34 (require 'message)
  35 (require 'gnus-util)
  36 (require 'gnus)
  37 (require 'nnmail)
  38 (require 'mm-util)
  39 (require 'mm-url)
  40 (eval-and-compile
  41   (ignore-errors
  42     (require 'url)))
  43 (autoload 'w3-parse-buffer "w3-parse")
  44
  45 (nnoo-declare nnweb)
  46
  47 (defvoo nnweb-directory (nnheader-concat gnus-directory "nnweb/")
  48   "Where nnweb will save its files.")
  49
  50 (defvoo nnweb-type 'google
  51   "What search engine type is being used.
  52 Valid types include `google', `dejanews', and `gmane'.")
  53
  54 (defvar nnweb-type-definition
  55   '((google
  56      (article . ignore)
  57      (id . "http://groups.google.com/groups?selm=%s&output=gplain")
  58      (reference . identity)
  59      (map . nnweb-google-create-mapping)
  60      (search . nnweb-google-search)
  61      (address . "http://groups.google.com/groups")
  62      (identifier . nnweb-google-identity))
  63     (dejanews ;; alias of google
  64      (article . ignore)
  65      (id . "http://groups.google.com/groups?selm=%s&output=gplain")
  66      (reference . identity)
  67      (map . nnweb-google-create-mapping)
  68      (search . nnweb-google-search)
  69      (address . "http://groups.google.com/groups")
  70      (identifier . nnweb-google-identity))
  71     (gmane
  72      (article . nnweb-gmane-wash-article)
  73      (id . "http://gmane.org/view.php?group=%s")
  74      (reference . identity)
  75      (map . nnweb-gmane-create-mapping)
  76      (search . nnweb-gmane-search)
  77      (address . "http://gmane.org/")
  78      (identifier . nnweb-gmane-identity)))
  79   "Type-definition alist.")
  80
  81 (defvoo nnweb-search nil
  82   "Search string to feed to Google.")
  83
  84 (defvoo nnweb-max-hits 999
  85   "Maximum number of hits to display.")
  86
  87 (defvoo nnweb-ephemeral-p nil
  88   "Whether this nnweb server is ephemeral.")
  89
  90 ;;; Internal variables
  91
  92 (defvoo nnweb-articles nil)
  93 (defvoo nnweb-buffer nil)
  94 (defvoo nnweb-group-alist nil)
  95 (defvoo nnweb-group nil)
  96 (defvoo nnweb-hashtb nil)
  97
  98 ;;; Interface functions
  99
 100 (nnoo-define-basics nnweb)
 101
 102 (deffoo nnweb-retrieve-headers (articles &optional group server fetch-old)
 103   (nnweb-possibly-change-server group server)
 104   (save-excursion
 105     (set-buffer nntp-server-buffer)
 106     (erase-buffer)
 107     (let (article header)
 108       (mm-with-unibyte-current-buffer
 109         (while (setq article (pop articles))
 110           (when (setq header (cadr (assq article nnweb-articles)))
 111             (nnheader-insert-nov header))))
 112       'nov)))
 113
 114 (deffoo nnweb-request-scan (&optional group server)
 115   (nnweb-possibly-change-server group server)
 116   (if nnweb-ephemeral-p
 117       (setq nnweb-hashtb (gnus-make-hashtable 4095)))
 118   (funcall (nnweb-definition 'map))
 119   (unless nnweb-ephemeral-p
 120     (nnweb-write-active)
 121     (nnweb-write-overview group)))
 122
 123 (deffoo nnweb-request-group (group &optional server dont-check)
 124   (nnweb-possibly-change-server nil server)
 125   (when (and group
 126              (not (equal group nnweb-group))
 127              (not nnweb-ephemeral-p))
 128     (setq nnweb-group group
 129           nnweb-articles nil)
 130     (let ((info (assoc group nnweb-group-alist)))
 131       (when info
 132         (setq nnweb-type (nth 2 info))
 133         (setq nnweb-search (nth 3 info))
 134         (unless dont-check
 135           (nnweb-read-overview group)))))
 136   (cond
 137    ((not nnweb-articles)
 138     (nnheader-report 'nnweb "No matching articles"))
 139    (t
 140     (let ((active (if nnweb-ephemeral-p
 141                       (cons (caar nnweb-articles)
 142                             (caar (last nnweb-articles)))
 143                     (cadr (assoc group nnweb-group-alist)))))
 144       (nnheader-report 'nnweb "Opened group %s" group)
 145       (nnheader-insert
 146        "211 %d %d %d %s\n" (length nnweb-articles)
 147        (car active) (cdr active) group)))))
 148
 149 (deffoo nnweb-close-group (group &optional server)
 150   (nnweb-possibly-change-server group server)
 151   (when (gnus-buffer-live-p nnweb-buffer)
 152     (save-excursion
 153       (set-buffer nnweb-buffer)
 154       (set-buffer-modified-p nil)
 155       (kill-buffer nnweb-buffer)))
 156   t)
 157
 158 (deffoo nnweb-request-article (article &optional group server buffer)
 159   (nnweb-possibly-change-server group server)
 160   (save-excursion
 161     (set-buffer (or buffer nntp-server-buffer))
 162     (let* ((header (cadr (assq article nnweb-articles)))
 163            (url (and header (mail-header-xref header))))
 164       (when (or (and url
 165                      (mm-with-unibyte-current-buffer
 166                        (mm-url-insert url)))
 167                 (and (stringp article)
 168                      (nnweb-definition 'id t)
 169                      (let ((fetch (nnweb-definition 'id))
 170                            art active)
 171                        (when (string-match "^<\\(.*\\)>$" article)
 172                          (setq art (match-string 1 article)))
 173                        (when (and fetch art)
 174                          (setq url (format fetch art))
 175                          (mm-with-unibyte-current-buffer
 176                            (mm-url-insert url))
 177                          (if (nnweb-definition 'reference t)
 178                              (setq article
 179                                    (funcall (nnweb-definition
 180                                              'reference) article)))))))
 181         (unless nnheader-callback-function
 182           (funcall (nnweb-definition 'article)))
 183         (nnheader-report 'nnweb "Fetched article %s" article)
 184         (cons group (and (numberp article) article))))))
 185
 186 (deffoo nnweb-close-server (&optional server)
 187   (when (and (nnweb-server-opened server)
 188              (gnus-buffer-live-p nnweb-buffer))
 189     (save-excursion
 190       (set-buffer nnweb-buffer)
 191       (set-buffer-modified-p nil)
 192       (kill-buffer nnweb-buffer)))
 193   (nnoo-close-server 'nnweb server))
 194
 195 (deffoo nnweb-request-list (&optional server)
 196   (nnweb-possibly-change-server nil server)
 197   (save-excursion
 198     (set-buffer nntp-server-buffer)
 199     (nnmail-generate-active nnweb-group-alist)
 200     t))
 201
 202 (deffoo nnweb-request-update-info (group info &optional server)
 203   (nnweb-possibly-change-server group server))
 204
 205 (deffoo nnweb-asynchronous-p ()
 206   nil)
 207
 208 (deffoo nnweb-request-create-group (group &optional server args)
 209   (nnweb-possibly-change-server nil server)
 210   (nnweb-request-delete-group group)
 211   (push `(,group ,(cons 1 0) ,@args) nnweb-group-alist)
 212   (nnweb-write-active)
 213   t)
 214
 215 (deffoo nnweb-request-delete-group (group &optional force server)
 216   (nnweb-possibly-change-server group server)
 217   (gnus-pull group nnweb-group-alist t)
 218   (nnweb-write-active)
 219   (gnus-delete-file (nnweb-overview-file group))
 220   t)
 221
 222 (nnoo-define-skeleton nnweb)
 223
 224 ;;; Internal functions
 225
 226 (defun nnweb-read-overview (group)
 227   "Read the overview of GROUP and build the map."
 228   (when (file-exists-p (nnweb-overview-file group))
 229     (mm-with-unibyte-buffer
 230       (nnheader-insert-file-contents (nnweb-overview-file group))
 231       (goto-char (point-min))
 232       (let (header)
 233         (while (not (eobp))
 234           (setq header (nnheader-parse-nov))
 235           (forward-line 1)
 236           (push (list (mail-header-number header)
 237                       header (mail-header-xref header))
 238                 nnweb-articles)
 239           (nnweb-set-hashtb header (car nnweb-articles)))))))
 240
 241 (defun nnweb-write-overview (group)
 242   "Write the overview file for GROUP."
 243   (with-temp-file (nnweb-overview-file group)
 244     (let ((articles nnweb-articles))
 245       (while articles
 246         (nnheader-insert-nov (cadr (pop articles)))))))
 247
 248 (defun nnweb-set-hashtb (header data)
 249   (gnus-sethash (nnweb-identifier (mail-header-xref header))
 250                 data nnweb-hashtb))
 251
 252 (defun nnweb-get-hashtb (url)
 253   (gnus-gethash (nnweb-identifier url) nnweb-hashtb))
 254
 255 (defun nnweb-identifier (ident)
 256   (funcall (nnweb-definition 'identifier) ident))
 257
 258 (defun nnweb-overview-file (group)
 259   "Return the name of the overview file of GROUP."
 260   (nnheader-concat nnweb-directory group ".overview"))
 261
 262 (defun nnweb-write-active ()
 263   "Save the active file."
 264   (gnus-make-directory nnweb-directory)
 265   (with-temp-file (nnheader-concat nnweb-directory "active")
 266     (prin1 `(setq nnweb-group-alist ',nnweb-group-alist) (current-buffer))))
 267
 268 (defun nnweb-read-active ()
 269   "Read the active file."
 270   (load (nnheader-concat nnweb-directory "active") t t t))
 271
 272 (defun nnweb-definition (type &optional noerror)
 273   "Return the definition of TYPE."
 274   (let ((def (cdr (assq type (assq nnweb-type nnweb-type-definition)))))
 275     (when (and (not def)
 276                (not noerror))
 277       (error "Undefined definition %s" type))
 278     def))
 279
 280 (defun nnweb-possibly-change-server (&optional group server)
 281   (nnweb-init server)
 282   (when server
 283     (unless (nnweb-server-opened server)
 284       (nnweb-open-server server)))
 285   (unless nnweb-group-alist
 286     (nnweb-read-active))
 287   (unless nnweb-hashtb
 288     (setq nnweb-hashtb (gnus-make-hashtable 4095)))
 289   (when group
 290     (when (and (not nnweb-ephemeral-p)
 291                (equal group nnweb-group))
 292       (nnweb-request-group group nil t))))
 293
 294 (defun nnweb-init (server)
 295   "Initialize buffers and such."
 296   (unless (gnus-buffer-live-p nnweb-buffer)
 297     (setq nnweb-buffer
 298           (save-excursion
 299             (mm-with-unibyte
 300               (nnheader-set-temp-buffer
 301                (format " *nnweb %s %s %s*"
 302                        nnweb-type nnweb-search server))
 303               (current-buffer))))))
 304
 305 ;;;
 306 ;;; Deja bought by google.com
 307 ;;;
 308
 309 (defun nnweb-google-wash-article ()
 310   (let ((case-fold-search t) url)
 311     (goto-char (point-min))
 312     (re-search-forward "^<pre>" nil t)
 313     (narrow-to-region (point-min) (point))
 314     (search-backward "<table " nil t 2)
 315     (delete-region (point-min) (point))
 316     (if (re-search-forward "Search Result [0-9]+" nil t)
 317         (replace-match ""))
 318     (if (re-search-forward "View complete thread ([0-9]+ articles?)" nil t)
 319         (replace-match ""))
 320     (goto-char (point-min))
 321     (while (search-forward "<br>" nil t)
 322       (replace-match "\n"))
 323     (mm-url-remove-markup)
 324     (goto-char (point-min))
 325     (while (re-search-forward "^[ \t]*\n" nil t)
 326       (replace-match ""))
 327     (goto-char (point-max))
 328     (insert "\n")
 329     (widen)
 330     (narrow-to-region (point) (point-max))
 331     (search-forward "</pre>" nil t)
 332     (delete-region (point) (point-max))
 333     (mm-url-remove-markup)
 334     (widen)))
 335
 336 (defun nnweb-google-parse-1 (&optional Message-ID)
 337   (let ((i 0)
 338         (case-fold-search t)
 339         (active (cadr (assoc nnweb-group nnweb-group-alist)))
 340         Subject Score Date Newsgroups From
 341         map url mid)
 342     (unless active
 343       (push (list nnweb-group (setq active (cons 1 0))
 344                   nnweb-type nnweb-search)
 345             nnweb-group-alist))
 346     ;; Go through all the article hits on this page.
 347     (goto-char (point-min))
 348     (while (re-search-forward
 349             "a href=/groups\\(\\?[^ \">]*selm=\\([^ &\">]+\\)\\)" nil t)
 350       (setq mid (match-string 2)
 351             url (format
 352                  "http://groups.google.com/groups?selm=%s&output=gplain" mid))
 353       (narrow-to-region (search-forward ">" nil t)
 354                         (search-forward "</a>" nil t))
 355       (mm-url-remove-markup)
 356       (mm-url-decode-entities)
 357       (setq Subject (buffer-string))
 358       (goto-char (point-max))
 359       (widen)
 360       (forward-line 2)
 361       (when (looking-at "<br><font[^>]+>")
 362         (goto-char (match-end 0)))
 363       (if (not (looking-at "<a[^>]+>"))
 364           (skip-chars-forward " \t")
 365         (narrow-to-region (point)
 366                           (search-forward "</a>" nil t))
 367         (mm-url-remove-markup)
 368         (mm-url-decode-entities)
 369         (setq Newsgroups (buffer-string))
 370         (goto-char (point-max))
 371         (widen)
 372         (skip-chars-forward "- \t"))
 373       (when (looking-at
 374              "\\([0-9]+\\)[/ ]\\([A-Za-z]+\\)[/ ]\\([0-9]+\\)[ \t]*by[ \t]*\\([^<]*\\) - <a")
 375         (setq From (match-string 4)
 376               Date (format "%s %s 00:00:00 %s"
 377                            (match-string 2) (match-string 1)
 378                            (match-string 3))))
 379       (forward-line 1)
 380       (incf i)
 381       (unless (nnweb-get-hashtb url)
 382         (push
 383          (list
 384           (incf (cdr active))
 385           (make-full-mail-header
 386            (cdr active) (if Newsgroups
 387                             (concat  "(" Newsgroups ") " Subject)
 388                           Subject)
 389            From Date (or Message-ID mid)
 390            nil 0 0 url))
 391          map)
 392         (nnweb-set-hashtb (cadar map) (car map))))
 393     map))
 394
 395 (defun nnweb-google-reference (id)
 396   (let ((map (nnweb-google-parse-1 id)) header)
 397     (setq nnweb-articles
 398           (nconc nnweb-articles map))
 399     (when (setq header (cadar map))
 400       (mm-with-unibyte-current-buffer
 401         (mm-url-insert (mail-header-xref header)))
 402       (caar map))))
 403
 404 (defun nnweb-google-create-mapping ()
 405   "Perform the search and create a number-to-url alist."
 406   (save-excursion
 407     (set-buffer nnweb-buffer)
 408     (erase-buffer)
 409     (when (funcall (nnweb-definition 'search) nnweb-search)
 410         (let ((more t)
 411               (i 0))
 412           (while more
 413             (setq nnweb-articles
 414                   (nconc nnweb-articles (nnweb-google-parse-1)))
 415             ;; Check if there are more articles to fetch
 416             (goto-char (point-min))
 417             (incf i 100)
 418             (if (or (not (re-search-forward
 419                           "<td nowrap><a href=\\([^>]+\\).*<span class=b>Next</span>" nil t))
 420                     (>= i nnweb-max-hits))
 421                 (setq more nil)
 422               ;; Yup, there are more articles
 423               (setq more (concat "http://groups.google.com" (match-string 1)))
 424             (when more
 425               (erase-buffer)
 426               (mm-url-insert more))))
 427           ;; Return the articles in the right order.
 428           (setq nnweb-articles
 429                 (sort nnweb-articles 'car-less-than-car))))))
 430
 431 (defun nnweb-google-search (search)
 432   (mm-url-insert
 433    (concat
 434     (nnweb-definition 'address)
 435     "?"
 436     (mm-url-encode-www-form-urlencoded
 437      `(("q" . ,search)
 438        ("num". "100")
 439        ("hq" . "")
 440        ("hl" . "")
 441        ("lr" . "")
 442        ("safe" . "off")
 443        ("sites" . "groups")))))
 444   t)
 445
 446 (defun nnweb-google-identity (url)
 447   "Return an unique identifier based on URL."
 448   (if (string-match "selm=\\([^ &>]+\\)" url)
 449       (match-string 1 url)
 450     url))
 451
 452 ;;;
 453 ;;; gmane.org
 454 ;;;
 455 (defun nnweb-gmane-create-mapping ()
 456   "Perform the search and create a number-to-url alist."
 457   (save-excursion
 458     (set-buffer nnweb-buffer)
 459     (erase-buffer)
 460     (when (funcall (nnweb-definition 'search) nnweb-search)
 461       (let ((more t)
 462             (case-fold-search t)
 463             (active (or (cadr (assoc nnweb-group nnweb-group-alist))
 464                         (cons 1 0)))
 465             subject group url
 466             map)
 467           ;; Remove stuff from the beginning of results
 468         (goto-char (point-min))
 469         (search-forward "Search Results</h1><ul>" nil t)
 470         (delete-region (point-min) (point))
 471         (goto-char (point-min))
 472         ;; Iterate over the actual hits
 473         (while (re-search-forward ".*href=\"\\([^\"]+\\)\">\\(.*\\)" nil t)
 474             (setq url (concat "http://gmane.org/" (match-string 1)))
 475             (setq subject (match-string 2))
 476           (unless (nnweb-get-hashtb url)
 477             (push
 478              (list
 479               (incf (cdr active))
 480               (make-full-mail-header
 481                (cdr active) (concat  "(" group ") " subject) nil nil
 482                nil nil 0 0 url))
 483              map)
 484             (nnweb-set-hashtb (cadar map) (car map))))
 485         ;; Return the articles in the right order.
 486         (setq nnweb-articles
 487               (sort (nconc nnweb-articles map) 'car-less-than-car))))))
 488
 489 (defun nnweb-gmane-wash-article ()
 490   (let ((case-fold-search t))
 491     (goto-char (point-min))
 492     (re-search-forward "<!--X-Head-of-Message-->" nil t)
 493     (delete-region (point-min) (point))
 494     (goto-char (point-min))
 495     (while (looking-at "^<li><em>\\([^ ]+\\)</em>.*</li>")
 496       (replace-match "\\1\\2" t)
 497       (forward-line 1))
 498     (mm-url-remove-markup)))
 499
 500 (defun nnweb-gmane-search (search)
 501   (mm-url-insert
 502    (concat
 503     (nnweb-definition 'address)
 504     "?"
 505     (mm-url-encode-www-form-urlencoded
 506      `(("query" . ,search)))))
 507   (setq buffer-file-name nil)
 508   t)
 509
 510
 511 (defun nnweb-gmane-identity (url)
 512   "Return a unique identifier based on URL."
 513   (if (string-match "group=\\(.+\\)" url)
 514       (match-string 1 url)
 515     url))
 516
 517 ;;;
 518 ;;; General web/w3 interface utility functions
 519 ;;;
 520
 521 (defun nnweb-insert-html (parse)
 522   "Insert HTML based on a w3 parse tree."
 523   (if (stringp parse)
 524       (insert (nnheader-string-as-multibyte parse))
 525     (insert "<" (symbol-name (car parse)) " ")
 526     (insert (mapconcat
 527              (lambda (param)
 528                (concat (symbol-name (car param)) "="
 529                        (prin1-to-string
 530                         (if (consp (cdr param))
 531                             (cadr param)
 532                           (cdr param)))))
 533              (nth 1 parse)
 534              " "))
 535     (insert ">\n")
 536     (mapcar 'nnweb-insert-html (nth 2 parse))
 537     (insert "</" (symbol-name (car parse)) ">\n")))
 538
 539 (defun nnweb-parse-find (type parse &optional maxdepth)
 540   "Find the element of TYPE in PARSE."
 541   (catch 'found
 542     (nnweb-parse-find-1 type parse maxdepth)))
 543
 544 (defun nnweb-parse-find-1 (type contents maxdepth)
 545   (when (or (null maxdepth)
 546             (not (zerop maxdepth)))
 547     (when (consp contents)
 548       (when (eq (car contents) type)
 549         (throw 'found contents))
 550       (when (listp (cdr contents))
 551         (dolist (element contents)
 552           (when (consp element)
 553             (nnweb-parse-find-1 type element
 554                                 (and maxdepth (1- maxdepth)))))))))
 555
 556 (defun nnweb-parse-find-all (type parse)
 557   "Find all elements of TYPE in PARSE."
 558   (catch 'found
 559     (nnweb-parse-find-all-1 type parse)))
 560
 561 (defun nnweb-parse-find-all-1 (type contents)
 562   (let (result)
 563     (when (consp contents)
 564       (if (eq (car contents) type)
 565           (push contents result)
 566         (when (listp (cdr contents))
 567           (dolist (element contents)
 568             (when (consp element)
 569               (setq result
 570                     (nconc result (nnweb-parse-find-all-1 type element))))))))
 571     result))
 572
 573 (defvar nnweb-text)
 574 (defun nnweb-text (parse)
 575   "Return a list of text contents in PARSE."
 576   (let ((nnweb-text nil))
 577     (nnweb-text-1 parse)
 578     (nreverse nnweb-text)))
 579
 580 (defun nnweb-text-1 (contents)
 581   (dolist (element contents)
 582     (if (stringp element)
 583         (push element nnweb-text)
 584       (when (and (consp element)
 585                  (listp (cdr element)))
 586         (nnweb-text-1 element)))))
 587
 588 (provide 'nnweb)
 589
 590 ;;; arch-tag: f59307eb-c90f-479f-b7d2-dbd8bf51b697
 591 ;;; nnweb.el ends here