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1 \input texinfo @c -*-texinfo-*- | |
2 @c documentation for forms-mode | |
3 @c Written by Johan Vromans, and edited by Richard Stallman | |
4 @c !Id: forms.texinfo,v 1.1 1994/04/05 07:43:19 jwz Exp ! | |
5 | |
6 @comment %**start of header (This is for running Texinfo on a region.) | |
7 @setfilename ../info/forms.info | |
8 @settitle Forms Mode User's Manual | |
9 @syncodeindex vr cp | |
10 @syncodeindex fn cp | |
11 @syncodeindex ky cp | |
12 @iftex | |
13 @finalout | |
14 @setchapternewpage odd | |
15 @end iftex | |
16 @c @smallbook | |
17 @comment %**end of header (This is for running Texinfo on a region.) | |
18 | |
19 @ifinfo | |
20 This file documents Forms mode, a form-editing major mode for GNU Emacs. | |
21 | |
22 Permission is granted to make and distribute verbatim copies of this | |
23 manual provided the copyright notice and this permission notice are | |
24 preserved on all copies. | |
25 | |
26 @ignore | |
27 Permission is granted to process this file through TeX and print the | |
28 results, provided the printed document carries copying permission notice | |
29 identical to this one except for the removal of this paragraph (this | |
30 paragraph not being relevant to the printed manual). | |
31 | |
32 @end ignore | |
33 @end ifinfo | |
34 | |
35 @iftex | |
36 @titlepage | |
37 @sp 6 | |
38 @center @titlefont{Forms Mode User's Manual} | |
39 @sp 4 | |
40 @center Forms-Mode version 2.3 | |
41 @sp 1 | |
42 @center September 1993 | |
43 @sp 5 | |
44 @center Johan Vromans | |
45 @center @i{jv@@nl.net} | |
46 @page | |
47 | |
48 @vskip 0pt plus 1filll | |
49 Copyright @copyright{} 1989, 1990, 1991, 1993 Free Software Foundation, Inc. | |
50 | |
51 Permission is granted to make and distribute verbatim copies of | |
52 this manual provided the copyright notice and this permission notice | |
53 are preserved on all copies. | |
54 @page | |
55 @end titlepage | |
56 @end iftex | |
57 | |
58 @ifinfo | |
59 @node Top | |
60 @top Forms Mode | |
61 @end ifinfo | |
62 | |
63 Forms mode is an Emacs major mode for working with simple textual data | |
64 bases in a forms-oriented manner. In Forms mode, the information in | |
65 these files is presented in an Emacs window in a user-defined format, | |
66 one record at a time. The user can view records or modify their | |
67 contents. | |
68 | |
69 Forms mode is not a simple major mode, but requires two files to do its | |
70 job: a control file and a data file. The data file holds the | |
71 actual data to be presented. The control file describes | |
72 how to present it. | |
73 | |
74 @menu | |
75 * Forms Example:: An example: editing the password data base. | |
76 * Entering and Exiting Forms Mode:: | |
77 How to visit a file in Forms mode. | |
78 * Forms Commands:: Special commands to use while in Forms mode. | |
79 * Data File Format:: How to format the data file. | |
80 * Control File Format:: How to control forms mode. | |
81 * Format Description:: How to define the forms layout. | |
82 * Modifying Forms Contents:: How to modify. | |
83 * Miscellaneous:: Forms mode messages and other remarks. | |
84 * Error Messages:: List of error messages forms mode can produce. | |
85 * Long Example:: A more complex control file example. | |
86 * Credits:: Thanks everyone. | |
87 * Index:: Index to this manual. | |
88 @end menu | |
89 | |
90 @node Forms Example | |
91 @chapter Forms Example | |
92 | |
93 Let's illustrate Forms mode with an example. Suppose you are looking at | |
94 the @file{/etc/passwd} file, and the screen looks like this: | |
95 | |
96 @example | |
97 ====== /etc/passwd ====== | |
98 | |
99 User : root Uid: 0 Gid: 1 | |
100 | |
101 Name : Super User | |
102 | |
103 Home : / | |
104 | |
105 Shell: /bin/sh | |
106 @end example | |
107 | |
108 As you can see, the familiar fields from the entry for the super user | |
109 are all there, but instead of being colon-separated on one single line, | |
110 they make up a forms. | |
111 | |
112 The contents of the forms consists of the contents of the fields of the | |
113 record (e.g. @samp{root}, @samp{0}, @samp{1}, @samp{Super User}) | |
114 interspersed with normal text (e.g @samp{User : }, @samp{Uid: }). | |
115 | |
116 If you modify the contents of the fields, Forms mode will analyze your | |
117 changes and update the file appropriately. You cannot modify the | |
118 interspersed explanatory text (unless you go to some trouble about it), | |
119 because that is marked read-only (@pxref{Text Properties,,, elisp, The | |
120 Emacs Lisp Reference Manual}). | |
121 | |
122 The Forms mode control file specifies the relationship between the | |
123 format of @file{/etc/passwd} and what appears on the screen in Forms | |
124 mode. @xref{Control File Format}. | |
125 | |
126 @node Entering and Exiting Forms Mode | |
127 @chapter Entering and Exiting Forms Mode | |
128 | |
129 @table @kbd | |
130 @findex forms-find-file | |
131 @item M-x forms-find-file @key{RET} @var{control-file} @key{RET} | |
132 Visit a database using Forms mode. Specify the name of the | |
133 @strong{control file}, not the data file! | |
134 | |
135 @findex forms-find-file-other-window | |
136 @item M-x forms-find-file-other-window @key{RET} @var{control-file} @key{RET} | |
137 Similar, but displays the file in another window. | |
138 @end table | |
139 | |
140 The command @code{forms-find-file} evaluates the file | |
141 @var{control-file}, and also visits it in Forms mode. What you see in | |
142 its buffer is not the contents of this file, but rather a single record | |
143 of the corresponding data file that is visited in its own buffer. So | |
144 there are two buffers involved in Forms mode: the @dfn{forms buffer} | |
145 that is initially used to visit the control file and that shows the | |
146 records being browsed, and the @dfn{data buffer} that holds the data | |
147 file being visited. The latter buffer is normally not visible. | |
148 | |
149 Initially, the first record is displayed in the forms buffer. | |
150 The mode line displays the major mode name @samp{Forms}, followed by the | |
151 minor mode @samp{View} if the data base is read-only. The number of the | |
152 current record (@var{n}) and the total number of records in the | |
153 file(@var{t}) are shown in the mode line as @samp{@var{n}/@var{t}}. For | |
154 example: | |
155 | |
156 @example | |
157 --%%-Emacs: passwd-demo (Forms View 1/54)----All------- | |
158 @end example | |
159 | |
160 If the buffer is not read-only, you may change the buffer to modify the | |
161 fields in the record. When you move to a different record, the contents | |
162 of the buffer are parsed using the specifications in | |
163 @code{forms-format-list}, and the data file is updated. If the record | |
164 has fields that aren't included in the display, they are not changed. | |
165 | |
166 @vindex forms-mode-hooks | |
167 Entering Forms mode runs the normal hook @code{forms-mode-hooks} to | |
168 perform user-defined customization. | |
169 | |
170 To save any modified data, you can use @kbd{C-x C-s} | |
171 (@code{save-buffer}). This does not save the forms buffer (which would | |
172 be rather useless), but instead saves the buffer visiting the data file. | |
173 | |
174 To terminate Forms mode, you can use @kbd{C-x C-s} (@code{save-buffer}) | |
175 and then kill the forms buffer. However, the data buffer will still | |
176 remain. If this is not desired, you have to kill this buffer too. | |
177 | |
178 @node Forms Commands | |
179 @chapter Forms Commands | |
180 | |
181 The commands of Forms mode belong to the @kbd{C-c} prefix, with one | |
182 exception: @key{TAB}, which moves to the next field. Forms mode uses | |
183 different key maps for normal mode and read-only mode. In read-only | |
184 Forms mode, you can access most of the commands without the @kbd{C-c} | |
185 prefix, but you must type ordinary letters instead of control | |
186 characters; for example, type @kbd{n} instead of @kbd{C-c C-n}. | |
187 | |
188 @table @kbd | |
189 @findex forms-next-record | |
190 @kindex C-c C-n | |
191 @item C-c C-n | |
192 Show the next record (@code{forms-next-record}). With a prefix | |
193 argument @var{n}, show the @var{n}th next record. | |
194 | |
195 @findex forms-prev-record | |
196 @kindex C-c C-p | |
197 @item C-c C-p | |
198 Show the previous record (@code{forms-prev-record}). With a prefix | |
199 argument @var{n}, show the @var{n}th previous record. | |
200 | |
201 @findex forms-jump-record | |
202 @kindex C-c C-l | |
203 @item C-c C-l | |
204 Jump to a record by number (@code{forms-jump-record}). Specify | |
205 the record number with a prefix argument. | |
206 | |
207 @findex forms-first-record | |
208 @kindex C-c < | |
209 @item C-c < | |
210 Jump to the first record (@code{forms-first-record}). | |
211 | |
212 @findex forms-last-record | |
213 @kindex C-c > | |
214 @item C-c > | |
215 Jump to the last record (@code{forms-last-record}). This command also | |
216 recalculates the number of records in the data file. | |
217 | |
218 @findex forms-next-field | |
219 @kindex @key{TAB} | |
220 @item @key{TAB} | |
221 @kindex C-c @key{TAB} | |
222 @itemx C-c @key{TAB} | |
223 Jump to the next field in the current record (@code{forms-next-field}). | |
224 With a numeric argument @var{n}, jump forward @var{n} fields. If this command | |
225 would move past the last field, it wraps around to the first field. | |
226 | |
227 @findex forms-toggle-read-only | |
228 @kindex C-c C-q | |
229 @item C-c C-q | |
230 Toggles read-only mode (@code{forms-toggle-read-only}). In read-only | |
231 Forms mode, you cannot edit the fields; most Forms mode commands can be | |
232 accessed without the prefix @kbd{C-c} if you use the normal letter | |
233 instead (for example, type @kbd{n} instead of @kbd{C-c C-n}). In edit | |
234 mode, you can edit the fields and thus change the contents of the data | |
235 base; you must begin Forms mode commands with @code{C-c}. Switching | |
236 to edit mode is allowed only if you have write access to the data file. | |
237 | |
238 @findex forms-insert-record | |
239 @kindex C-c C-o | |
240 @item C-c C-o | |
241 Create a new record and insert it before the current record | |
242 (@code{forms-insert-record}). It starts out with empty (or default) | |
243 contents for its fields; you can then edit the fields. With a prefix | |
244 argument, the new record is created @emph{after} the current one. | |
245 See also @code{forms-modified-record-filter} in @ref{Modifying Forms | |
246 Contents}. | |
247 | |
248 @findex forms-delete-record | |
249 @kindex C-c C-k | |
250 @item C-c C-k | |
251 Delete the current record (@code{forms-delete-record}). You are | |
252 prompted for confirmation before the record is deleted unless a prefix | |
253 argument has been provided. | |
254 | |
255 @findex forms-search | |
256 @kindex C-c C-s @var{regexp} @key{RET} | |
257 @item C-c C-s @var{regexp} @key{RET} | |
258 Search for @var{regexp} in all records following this one | |
259 (@code{forms-search}). If found, this record is shown. If you give an | |
260 empty argument, the previous regexp is used again. | |
261 | |
262 @ignore | |
263 @findex forms-exit | |
264 @kindex C-c C-x | |
265 @item C-c C-x | |
266 Terminate Forms mode processing (@code{forms-exit}). The data file is | |
267 saved if it has been modified. | |
268 | |
269 @findex forms-exit-no-save | |
270 @item M-x forms-exit-no-save | |
271 Terminates forms mode processing without saving modified data first. | |
272 @end ignore | |
273 | |
274 @findex forms-prev-field | |
275 @item M-x forms-prev-field | |
276 Similar to @code{forms-next-field} but moves backwards. | |
277 @end table | |
278 | |
279 In addition, commands such as @kbd{C-x C-s} (@code{save-buffer}) and | |
280 @kbd{M-x revert-buffer} are useful in Forms mode just as in other modes. | |
281 | |
282 @ignore | |
283 @vindex forms-forms-scroll | |
284 @findex scroll-up | |
285 @findex scroll-down | |
286 If the variable @code{forms-forms-scrolls} is set to a value other | |
287 than @code{nil} (which it is, by default), the Emacs functions | |
288 @code{scroll-up} and @code{scroll-down} will perform a | |
289 @code{forms-next-record} and @code{forms-prev-record} when in forms | |
290 mode. So you can use your favourite page commands to page through the | |
291 data file. | |
292 | |
293 @vindex forms-forms-jump | |
294 @findex beginning-of-buffer | |
295 @findex end-of-buffer | |
296 Likewise, if the variable @code{forms-forms-jump} is not @code{nil} | |
297 (which it is, by default), Emacs functions @code{beginning-of-buffer} | |
298 and @code{end-of-buffer} will perform @code{forms-first-record} and | |
299 @code{forms-last-record} when in forms mode. | |
300 @end ignore | |
301 | |
302 The following function key definitions are set up in Forms mode | |
303 (whether read-only or not): | |
304 | |
305 @table @kbd | |
306 @kindex next | |
307 @item next | |
308 forms-next-record | |
309 | |
310 @kindex prior | |
311 @item prior | |
312 forms-prev-record | |
313 | |
314 @kindex begin | |
315 @item begin | |
316 forms-first-record | |
317 | |
318 @kindex end | |
319 @item end | |
320 forms-last-record | |
321 | |
322 @kindex S-Tab | |
323 @findex forms-prev-field | |
324 @item S-Tab | |
325 forms-prev-field | |
326 @end table | |
327 | |
328 @node Data File Format | |
329 @chapter Data File Format | |
330 | |
331 @cindex record | |
332 @cindex field | |
333 @vindex forms-field-sep | |
334 Files for use with Forms mode are very simple---each @dfn{record} | |
335 (usually one line) forms the contents of one form. Each record consists | |
336 of a number of @dfn{fields}, which are separated by the value of the | |
337 string @code{forms-field-sep}, which is @code{"\t"} (a tab) by default. | |
338 | |
339 @cindex pseudo-newline | |
340 @vindex forms-multi-line | |
341 Fields may contain text which shows up in the forms in multiple lines. | |
342 These lines are separated in the field using a ``pseudo-newline'' | |
343 character which is defined by the value of the string | |
344 @code{forms-multi-line}. Its default value is @code{"\^k"}. If it is | |
345 set to @code{nil}, multiple line fields are prohibited. | |
346 | |
347 @node Control File Format | |
348 @chapter Control File Format | |
349 | |
350 @cindex control file | |
351 The Forms mode @dfn{control file} serves two purposes. First, it names | |
352 the data file to use, and defines its format and properties. Second, | |
353 the Emacs buffer it occupies is used by Forms mode to display the forms. | |
354 | |
355 The contents of the control file are evaluated as a Lisp program. It | |
356 should set the following Lisp variables to suitable values: | |
357 | |
358 @table @code | |
359 @vindex forms-file | |
360 @item forms-file | |
361 This variable specifies the name of the data file. Example: | |
362 | |
363 @example | |
364 (setq forms-file "my/data-file") | |
365 @end example | |
366 | |
367 @vindex forms-format-list | |
368 @item forms-format-list | |
369 This variable describes the way the fields of the record are formatted on | |
370 the screen. For details, see @ref{Format Description}. | |
371 | |
372 @vindex forms-number-of-fields | |
373 @item forms-number-of-fields | |
374 This variable holds the number of fields in each record of the data | |
375 file. Example: | |
376 | |
377 @example | |
378 (setq forms-number-of-fields 10) | |
379 @end example | |
380 @end table | |
381 | |
382 If the control file doesn't set all of these variables, Forms mode | |
383 reports an error. | |
384 | |
385 The control file can optionally set the following additional Forms mode | |
386 variables. Most of them have default values that are good for most | |
387 applications. | |
388 | |
389 @table @code | |
390 @vindex forms-field-sep | |
391 @item forms-field-sep | |
392 This variable may be used to designate the string which separates the | |
393 fields in the records of the data file. If not set, it defaults to the | |
394 string @code{"\t"} (a tab character). Example: | |
395 | |
396 @example | |
397 (setq forms-field-sep "\t") | |
398 @end example | |
399 | |
400 @vindex forms-read-only | |
401 @item forms-read-only | |
402 If the value is non-@code{nil}, the data file is treated read-only. (Forms | |
403 mode also treats the data file as read-only if you don't have access to | |
404 write it.) Example: | |
405 | |
406 @example | |
407 (set forms-read-only t) | |
408 @end example | |
409 | |
410 @vindex forms-multi-line | |
411 @item forms-multi-line | |
412 This variable specifies the @dfn{pseudo newline} separator that allows | |
413 multi-line fields. This separator goes between the ``lines'' within a | |
414 field---thus, the field doesn't really contain multiple lines, but it | |
415 appears that way when displayed in Forms mode. If the value is | |
416 @code{nil}, multi-line text fields are prohibited. The pseudo newline | |
417 must not be a character contained in @code{forms-field-sep}. | |
418 | |
419 The default value is @code{"\^k"}, so the default pseudo newline is the | |
420 character control-k. Example: | |
421 | |
422 @example | |
423 (setq forms-multi-line "\^k") | |
424 @end example | |
425 | |
426 @ignore | |
427 @vindex forms-forms-scroll | |
428 @item forms-forms-scroll | |
429 @xref{Forms Mode Commands}, for details. | |
430 | |
431 @vindex forms-forms-jump | |
432 @item forms-forms-jump | |
433 @xref{Forms Mode Commands}, for details. | |
434 @end ignore | |
435 | |
436 @findex forms-new-record-filter | |
437 @item forms-new-record-filter | |
438 This variable holds a function to be called whenever a new record is created | |
439 to supply default values for fields. If it is @code{nil}, no function is | |
440 called. | |
441 @xref{Modifying Forms Contents}, for details. | |
442 | |
443 @findex forms-modified-record-filter | |
444 @item forms-modified-record-filter | |
445 This variable holds a function to be called whenever a record is | |
446 modified, just before updating the Forms data file. If it is | |
447 @code{nil}, no function is called. | |
448 @xref{Modifying Forms Contents}, for details. | |
449 @end table | |
450 | |
451 @node Format Description | |
452 @chapter The Format Description | |
453 | |
454 @vindex forms-format-list | |
455 The variable @code{forms-format-list} specifies the format of the data | |
456 in the data file, and how to convert the data for display in Forms mode. | |
457 Its value must be a list of Forms mode @dfn{formatting elements}, each | |
458 of which can be a string, a number, a Lisp list, or a Lisp symbol that | |
459 evaluates to one of those. The formatting elements are processed in the | |
460 order they appear in the list. | |
461 | |
462 @table @var | |
463 @item string | |
464 A string formatting element is inserted in the forms ``as is,'' as text | |
465 that the user cannot alter. | |
466 | |
467 @item number | |
468 A number element selects a field of the record. The contents of this | |
469 field are inserted in the display at this point. Field numbers count | |
470 starting from 1 (one). | |
471 | |
472 @item list | |
473 A formatting element that is a list specifies a function call. This | |
474 function is called every time a record is displayed, and its result, | |
475 which must be a string, is inserted in the display text. The function | |
476 should do nothing but returning a string. | |
477 | |
478 @vindex forms-fields | |
479 The function you call can access the fields of the record as a list in | |
480 the variable | |
481 @code{forms-fields}. | |
482 | |
483 @item symbol | |
484 A symbol used as a formatting element should evaluate to a string, number, | |
485 or list; the value is interpreted as a formatting element, as described | |
486 above. | |
487 @end table | |
488 | |
489 If a record does not contain the number of fields as specified in | |
490 @code{forms-number-of-fields}, a warning message will be printed. Excess | |
491 fields are ignored, missing fields are set to empty. | |
492 | |
493 The control file which displays @file{/etc/passwd} file as demonstrated | |
494 in the beginning of this manual might look as follows: | |
495 | |
496 @example | |
497 ;; @r{This demo visits @file{/etc/passwd}.} | |
498 | |
499 (setq forms-file "/etc/passwd") | |
500 (setq forms-number-of-fields 7) | |
501 (setq forms-read-only t) ; @r{to make sure} | |
502 (setq forms-field-sep ":") | |
503 ;; @r{Don't allow multi-line fields.} | |
504 (setq forms-multi-line nil) | |
505 | |
506 (setq forms-format-list | |
507 (list | |
508 "====== /etc/passwd ======\n\n" | |
509 "User : " 1 | |
510 " Uid: " 3 | |
511 " Gid: " 4 | |
512 "\n\n" | |
513 "Name : " 5 | |
514 "\n\n" | |
515 "Home : " 6 | |
516 "\n\n" | |
517 "Shell: " 7 | |
518 "\n")) | |
519 @end example | |
520 | |
521 When you construct the value of @code{forms-format-list}, you should | |
522 usually either quote the whole value, like this, | |
523 | |
524 @example | |
525 (setq forms-format-list | |
526 '( | |
527 "====== " forms-file " ======\n\n" | |
528 "User : " 1 | |
529 (make-string 20 ?-) | |
530 @dots{} | |
531 )) | |
532 @end example | |
533 | |
534 @noindent | |
535 or quote the elements which are lists, like this: | |
536 | |
537 @example | |
538 (setq forms-format-list | |
539 (list | |
540 "====== " forms-file " ======\n\n" | |
541 "User : " 1 | |
542 '(make-string 20 ?-) | |
543 @dots{} | |
544 )) | |
545 @end example | |
546 | |
547 Forms mode validates the contents of @code{forms-format-list} when you | |
548 visit a database. If there are errors, processing is aborted with an | |
549 error message which includes a descriptive text. @xref{Error Messages}, | |
550 for a detailed list of error messages. | |
551 | |
552 @node Modifying Forms Contents | |
553 @chapter Modifying The Forms Contents | |
554 | |
555 If @code{forms-read-only} is @code{nil}, the user can modify the fields | |
556 and records of the database. | |
557 | |
558 All normal editing commands are available for editing the contents of the | |
559 displayed record. You cannot delete or modify the fixed, explanatory | |
560 text that comes from string formatting elements, but you can modify the | |
561 actual field contents. | |
562 | |
563 @ignore | |
564 @c This is for the Emacs 18 version only. | |
565 If the contents of the forms cannot be recognized properly, this is | |
566 signaled using a descriptive text. @xref{Error Messages}, for more info. | |
567 The cursor will indicate the last part of the forms which was | |
568 successfully parsed. It's important to avoid entering field contents | |
569 that would cause confusion with the field-separating fixed text. | |
570 @end ignore | |
571 | |
572 If the variable @code{forms-modified-record-filter} is non-@code{nil}, | |
573 it is called as a function before the new data is written to the data | |
574 file. The function receives one argument, a vector that contains the | |
575 contents of the fields of the record. | |
576 | |
577 The function can refer to fields with @code{aref} and modify them with | |
578 @code{aset}. The first field has number 1 (one); thus, element 0 of the | |
579 vector is not used. The function should return the same vector it was | |
580 passed; the (possibly modified) contents of the vector determine what is | |
581 actually written in the file. Here is an example: | |
582 | |
583 @example | |
584 (defun my-modified-record-filter (record) | |
585 ;; @r{Modify second field.} | |
586 (aset record 2 (current-time-string)) | |
587 ;; @r{Return the field vector.} | |
588 record) | |
589 | |
590 (setq forms-modified-record-filter 'my-modified-record-filter) | |
591 @end example | |
592 | |
593 If the variable @code{forms-new-record-filter} is non-@code{nil}, its | |
594 value is a function to be called to fill in default values for the | |
595 fields of a new record. The function is passed a vector of empty | |
596 strings, one for each field; it should return the same vector, with | |
597 the desired field values stored in it. Fields are numbered starting | |
598 from 1 (one). Example: | |
599 | |
600 @example | |
601 (defun my-new-record-filter (fields) | |
602 (aset fields 5 (login-name)) | |
603 (aset fields 1 (current-time-string)) | |
604 fields) | |
605 | |
606 (setq forms-new-record-filter 'my-new-record-filter) | |
607 @end example | |
608 | |
609 @node Miscellaneous | |
610 @chapter Miscellaneous | |
611 | |
612 @vindex forms-version | |
613 The global variable @code{forms-version} holds the version information | |
614 of the Forms mode software. | |
615 | |
616 @findex forms-enumerate | |
617 It is very convenient to use symbolic names for the fields in a record. | |
618 The function @code{forms-enumerate} provides an elegant means to define | |
619 a series of variables whose values are consecutive integers. The | |
620 function returns the highest number used, so it can be used to set | |
621 @code{forms-number-of-fields} also. For example: | |
622 | |
623 @example | |
624 (setq forms-number-of-fields | |
625 (forms-enumerate | |
626 '(field1 field2 field3 @dots{}))) | |
627 @end example | |
628 | |
629 This sets @code{field1} to 1, @code{field2} to 2, and so on. | |
630 | |
631 Care has been taken to keep the Forms mode variables buffer-local, so it | |
632 is possible to visit multiple files in Forms mode simultaneously, even | |
633 if they have different properties. | |
634 | |
635 @findex forms-mode | |
636 If you have visited the control file in normal fashion with | |
637 @code{find-file} or a like command, you can switch to Forms mode with | |
638 the command @code{M-x forms-mode}. If you put @samp{-*- forms -*-} in | |
639 the first line of the control file, then visiting it enables Forms mode | |
640 automatically. But this makes it hard to edit the control file itself, | |
641 so you'd better think twice before using this. | |
642 | |
643 The default format for the data file, using @code{"\t"} to separate | |
644 fields and @code{"\^k"} to separate lines within a field, matches the | |
645 file format of some popular database programss, e.g. FileMaker. So | |
646 @code{forms-mode} can decrease the need to use proprietary software. | |
647 | |
648 @node Error Messages | |
649 @chapter Error Messages | |
650 | |
651 This section describes all error messages which can be generated by | |
652 forms mode. Error messages that result from parsing the control file | |
653 all start with the text @samp{Forms control file error}. Messages | |
654 generated while analyzing the definition of @code{forms-format-list} | |
655 start with @samp{Forms format error}. | |
656 | |
657 @table @code | |
658 @item Forms control file error: 'forms-file' has not been set | |
659 The variable @code{forms-file} was not set by the control file. | |
660 | |
661 @item Forms control file error: 'forms-number-of-fields' has not been set | |
662 The variable @code{forms-number-of-fields} was not set by the control | |
663 file. | |
664 | |
665 @item Forms control file error: 'forms-number-of-fields' must be a number > 0 | |
666 The variable @code{forms-number-of-fields} did not contain a positive | |
667 number. | |
668 | |
669 @item Forms control file error: 'forms-field-sep' is not a string | |
670 @itemx Forms control file error: 'forms-multi-line' must be nil or a one-character string | |
671 The variable @code{forms-multi-line} was set to something other than | |
672 @code{nil} or a single-character string. | |
673 | |
674 @item Forms control file error: 'forms-multi-line' is equal to 'forms-field-sep' | |
675 The variable @code{forms-multi-line} may not be equal to | |
676 @code{forms-field-sep} for this would make it impossible to distinguish | |
677 fields and the lines in the fields. | |
678 | |
679 @item Forms control file error: 'forms-new-record-filter' is not a function | |
680 @itemx Forms control file error: 'forms-modified-record-filter' is not a function | |
681 The variable has been set to something else than a function. | |
682 | |
683 @item Forms control file error: 'forms-format-list' has not been set | |
684 @itemx Forms control file error: 'forms-format-list' is not a list | |
685 The variable @code{forms-format-list} was not set to a Lisp list | |
686 by the control file. | |
687 | |
688 @item Forms format error: field number @var{xx} out of range 1..@var{nn} | |
689 A field number was supplied in @code{forms-format-list} with a value of | |
690 @var{xx}, which was not greater than zero and smaller than or equal to | |
691 the number of fields in the forms, @var{nn}. | |
692 | |
693 @item Forms format error: not a function @var{fun} | |
694 The first element of a list which is an element of | |
695 @code{forms-format-list} was not a valid Lisp function. | |
696 | |
697 @item Forms format error: invalid element @var{xx} | |
698 A list element was supplied in @code{forms-format-list} which was not a | |
699 string, number or list. | |
700 | |
701 @ignore | |
702 @c This applies to Emacs 18 only. | |
703 @c Error messages generated while a modified form is being analyzed. | |
704 | |
705 @item Parse error: not looking at "..." | |
706 When re-parsing the contents of a forms, the text shown could not | |
707 be found. | |
708 | |
709 @item Parse error: cannot find "..." | |
710 When re-parsing the contents of a forms, the text shown, which | |
711 separates two fields, could not be found. | |
712 | |
713 @item Parse error: cannot parse adjacent fields @var{xx} and @var{yy} | |
714 Fields @var{xx} and @var{yy} were not separated by text, so could not be | |
715 parsed again. | |
716 @end ignore | |
717 | |
718 @item Warning: this record has @var{xx} fields instead of @var{yy} | |
719 The number of fields in this record in the data file did not match | |
720 @code{forms-number-of-fields}. Missing fields will be made empty. | |
721 | |
722 @item Multi-line fields in this record - update refused! | |
723 The current record contains newline characters, hence can not be written | |
724 back to the data file, for it would corrupt it. Probably you inserted a | |
725 newline in a field, while @code{forms-multi-line} was @code{nil}. | |
726 | |
727 @item Record number @var{xx} out of range 1..@var{yy} | |
728 A jump was made to non-existing record @var{xx}. @var{yy} denotes the | |
729 number of records in the file. | |
730 | |
731 @item Stuck at record @var{xx} | |
732 An internal error prevented a specific record from being retrieved. | |
733 | |
734 @item No write access to @code{"}@var{file}@code{"} | |
735 An attempt was made to enable edit mode on a file that has been write | |
736 protected. | |
737 | |
738 @item @code{"}@var{regexp}@code{"} not found | |
739 The @var{regexp} could not be found in the data file, starting at the | |
740 current record location. | |
741 | |
742 @item Warning: number of records changed to @var{nn} | |
743 Forms mode's idea of the number of records has been adjusted to the | |
744 number of records actually present in the data file. | |
745 | |
746 @item Problem saving buffers? | |
747 An error occurred while saving the data file buffer. Most likely, Emacs | |
748 did ask to confirm deleting the buffer because it had been modified, and | |
749 you said `no'. | |
750 @end table | |
751 | |
752 @node Long Example | |
753 @chapter Long Example | |
754 | |
755 The following example exploits most of the features of Forms mode. | |
756 This example is included in the distribution as file @file{forms-d2.el}. | |
757 | |
758 @example | |
759 ;; demo2 -- demo forms-mode -*- emacs-lisp -*- | |
760 | |
761 ;; SCCS Status : demo2 1.1.2 | |
762 ;; Author : Johan Vromans | |
763 ;; Created On : 1989 | |
764 ;; Last Modified By: Johan Vromans | |
765 ;; Last Modified On: Mon Jul 1 13:56:31 1991 | |
766 ;; Update Count : 2 | |
767 ;; Status : OK | |
768 ;; | |
769 ;; @r{This sample forms exploit most of the features of forms mode.} | |
770 | |
771 ;; @r{Set the name of the data file.} | |
772 (setq forms-file "forms-d2.dat") | |
773 | |
774 ;; @r{Use @code{forms-enumerate} to set field names and number thereof.} | |
775 (setq forms-number-of-fields | |
776 (forms-enumerate | |
777 '(arch-newsgroup ; 1 | |
778 arch-volume ; 2 | |
779 arch-issue ; and ... | |
780 arch-article ; ... so | |
781 arch-shortname ; ... ... on | |
782 arch-parts | |
783 arch-from | |
784 arch-longname | |
785 arch-keywords | |
786 arch-date | |
787 arch-remarks))) | |
788 | |
789 ;; @r{The following functions are used by this form for layout purposes.} | |
790 ;; | |
791 (defun arch-tocol (target &optional fill) | |
792 "Produces a string to skip to column TARGET. | |
793 Prepends newline if needed. | |
794 The optional FILL should be a character, used to fill to the column." | |
795 (if (null fill) | |
796 (setq fill ? )) | |
797 (if (< target (current-column)) | |
798 (concat "\n" (make-string target fill)) | |
799 (make-string (- target (current-column)) fill))) | |
800 ;; | |
801 (defun arch-rj (target field &optional fill) | |
802 "Produces a string to skip to column TARGET\ | |
803 minus the width of field FIELD. | |
804 Prepends newline if needed. | |
805 The optional FILL should be a character, | |
806 used to fill to the column." | |
807 (arch-tocol (- target (length (nth field forms-fields))) fill)) | |
808 | |
809 ;; @r{Record filters.} | |
810 ;; | |
811 (defun new-record-filter (the-record) | |
812 "Form a new record with some defaults." | |
813 (aset the-record arch-from (user-full-name)) | |
814 (aset the-record arch-date (current-time-string)) | |
815 the-record) ; return it | |
816 (setq forms-new-record-filter 'new-record-filter) | |
817 | |
818 ;; @r{The format list.} | |
819 (setq forms-format-list | |
820 (list | |
821 "====== Public Domain Software Archive ======\n\n" | |
822 arch-shortname | |
823 " - " arch-longname | |
824 "\n\n" | |
825 "Article: " arch-newsgroup | |
826 "/" arch-article | |
827 " " | |
828 '(arch-tocol 40) | |
829 "Issue: " arch-issue | |
830 " " | |
831 '(arch-rj 73 10) | |
832 "Date: " arch-date | |
833 "\n\n" | |
834 "Submitted by: " arch-from | |
835 "\n" | |
836 '(arch-tocol 79 ?-) | |
837 "\n" | |
838 "Keywords: " arch-keywords | |
839 "\n\n" | |
840 "Parts: " arch-parts | |
841 "\n\n====== Remarks ======\n\n" | |
842 arch-remarks | |
843 )) | |
844 | |
845 ;; @r{That's all, folks!} | |
846 @end example | |
847 | |
848 @node Credits | |
849 @chapter Credits | |
850 | |
851 Forms mode was developed by Johan Vromans while working at Multihouse | |
852 Research in the Netherlands. | |
853 | |
854 Bug fixes and other useful suggestions were supplied by | |
855 Richard Stallman (@code{rms@@gnu.ai.mit.edu}), | |
856 Harald Hanche-Olsen (@code{hanche@@imf.unit.no}), | |
857 @code{cwitty@@portia.stanford.edu}, | |
858 Jonathan I. Kamens, | |
859 Per Cederqvist (@code{ceder@@signum.se}), | |
860 and Ignatios Souvatzis. | |
861 | |
862 This documentation was slightly inspired by the documentation of ``rolo | |
863 mode'' by Paul Davis at Schlumberger Cambridge Research | |
864 (@code{davis%scrsu1%sdr.slb.com@@relay.cs.net}). | |
865 | |
866 None of this would have been possible without GNU Emacs of the Free | |
867 Software Foundation. Thanks, Richard! | |
868 | |
869 @node Index | |
870 @unnumbered Index | |
871 @printindex cp | |
872 | |
873 @contents | |
874 @bye |