0000: 47 6f 74 63 68 61 73 21 0a 3d 3d 3d 3d 3d 3d 3d Gotchas!.=======
0010: 0a 0a 31 2e 20 41 6c 6c 20 69 74 65 6d 73 20 66 ..1. All items f
0020: 6f 72 20 61 20 70 61 67 65 20 2a 6d 75 73 74 2a or a page *must*
0030: 20 62 65 20 70 61 72 74 20 6f 66 20 61 20 6c 69 be part of a li
0040: 73 74 21 0a 0a 20 20 20 4f 4b 3a 20 20 20 20 20 st!.. OK:
0050: 28 6c 69 73 74 20 28 66 75 6e 63 74 69 6f 6e 31 (list (function1
0060: 20 70 61 72 61 6d 31 29 28 66 75 6e 63 74 69 6f param1)(functio
0070: 6e 32 20 70 61 72 61 6d 32 29 29 0a 20 20 20 4e n2 param2)). N
0080: 4f 54 20 4f 4b 3a 20 28 62 65 67 69 6e 20 28 66 OT OK: (begin (f
0090: 75 6e 63 74 69 6f 6e 31 20 70 61 72 61 6d 31 29 unction1 param1)
00a0: 28 66 75 6e 63 74 69 6f 6e 32 20 70 61 72 61 6d (function2 param
00b0: 32 29 29 0a 0a 0a 56 61 72 69 6f 75 73 20 63 6f 2))...Various co
00c0: 6d 70 6f 6e 65 6e 74 73 0a 3d 3d 3d 3d 3d 3d 3d mponents.=======
00d0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 0a 0a 3d 3d 3d ===========..===
00e0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
00f0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0100: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0110: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0120: 3d 3d 3d 0a 31 2e 20 43 72 65 61 74 65 20 61 20 ===.1. Create a
0130: 6c 69 6e 6b 2e 0a 0a 28 73 3a 6e 75 6c 6c 20 22 link...(s:null "
0140: 5b 22 20 28 73 3a 61 20 6e 61 6d 65 20 27 68 72 [" (s:a name 'hr
0150: 65 66 20 0a 20 20 20 20 20 20 20 20 20 20 20 20 ef .
0160: 20 20 20 28 73 3a 6c 69 6e 6b 2d 74 6f 20 28 73 (s:link-to (s
0170: 74 72 69 6e 67 2d 61 70 70 65 6e 64 20 22 6c 6f tring-append "lo
0180: 63 61 74 69 6f 6e 2f 22 20 28 73 74 72 69 6e 67 cation/" (string
0190: 2d 69 6e 74 65 72 73 70 65 72 73 65 20 70 20 22 -intersperse p "
01a0: 2f 22 29 20 22 22 29 29 29 20 22 5d 20 22 29 29 /") ""))) "] "))
01b0: 29 0a 0a 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d )..=============
01c0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
01d0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
01e0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
01f0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 0a 32 2e 20 43 61 6c =========.2. Cal
0200: 6c 20 63 75 72 72 65 6e 74 20 70 61 67 65 20 77 l current page w
0210: 69 74 68 20 6e 65 77 20 70 61 72 61 6d 0a 0a 49 ith new param..I
0220: 6e 20 76 69 65 77 2e 73 63 6d 3a 0a 0a 20 28 73 n view.scm:.. (s
0230: 3a 63 65 6e 74 65 72 20 22 5b 22 20 28 73 3a 61 :center "[" (s:a
0240: 20 27 68 72 65 66 20 28 73 3a 6c 69 6e 6b 2d 74 'href (s:link-t
0250: 6f 20 22 70 6f 6c 6c 73 22 0a 20 20 20 20 20 20 o "polls".
0260: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
0270: 20 20 20 20 20 27 69 64 0a 20 20 20 20 20 20 20 'id.
0280: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
0290: 20 20 20 20 20 28 62 65 67 69 6e 0a 20 20 20 20 (begin.
02a0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
02b0: 20 20 20 20 20 20 20 20 20 20 28 70 6f 6c 6c 3a (poll:
02c0: 70 6f 6c 6c 20 27 66 69 6c 6c 2d 70 6f 6c 6c 73 poll 'fill-polls
02d0: 29 0a 20 20 20 20 20 20 20 20 20 20 20 20 20 20 ).
02e0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
02f0: 28 70 6f 6c 6c 3a 70 6f 6c 6c 20 27 67 65 74 2d (poll:poll 'get-
0300: 6e 65 78 74 2d 70 6f 6c 6c 29 29 29 0a 20 20 20 next-poll))).
0310: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
0320: 20 20 20 20 20 20 20 22 47 6f 20 74 6f 20 74 68 "Go to th
0330: 65 20 6e 65 78 74 20 70 6f 6c 6c 22 29 20 20 22 e next poll") "
0340: 5d 22 29 0a 0a 49 6e 20 63 6f 6e 74 72 6f 6c 2e ]")..In control.
0350: 73 63 6d 3a 0a 0a 28 6c 65 74 20 28 28 70 6f 6c scm:..(let ((pol
0360: 6c 2d 69 64 20 28 73 3a 67 65 74 2d 70 61 72 61 l-id (s:get-para
0370: 6d 20 27 69 64 29 29 29 0a 20 3b 3b 20 64 6f 20 m 'id))). ;; do
0380: 73 74 75 66 66 20 62 61 73 65 64 20 6f 6e 20 70 stuff based on p
0390: 6f 6c 6c 2d 69 64 0a 0a 3d 3d 3d 3d 3d 3d 3d 3d oll-id..========
03a0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
03b0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
03c0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
03d0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 0a 33 ==============.3
03e0: 2e 20 43 61 6c 6c 20 61 6e 20 61 63 74 69 6f 6e . Call an action
03f0: 20 6f 6e 20 61 20 73 70 65 63 69 66 69 63 20 70 on a specific p
0400: 61 67 65 0a 0a 20 28 73 3a 61 20 27 68 72 65 66 age.. (s:a 'href
0410: 20 28 73 3a 6c 69 6e 6b 2d 74 6f 20 22 70 6f 6c (s:link-to "pol
0420: 6c 73 22 20 27 69 64 20 28 70 6f 6c 6c 3a 70 6f ls" 'id (poll:po
0430: 6c 6c 20 27 67 65 74 20 27 69 64 29 20 0a 09 09 ll 'get 'id) ...
0440: 09 20 20 20 20 20 20 20 27 61 63 74 69 6f 6e 20 . 'action
0450: 22 70 6f 6c 6c 2e 65 64 69 74 22 29 0a 20 20 20 "poll.edit").
0460: 20 20 20 20 20 20 20 20 20 22 53 75 67 67 65 73 "Sugges
0470: 74 20 63 68 61 6e 67 65 73 20 74 6f 20 74 68 69 t changes to thi
0480: 73 20 70 6f 6c 6c 22 29 0a 0a 20 4e 4f 54 20 54 s poll").. NOT T
0490: 52 55 45 21 20 54 68 69 73 20 63 61 6c 6c 73 20 RUE! This calls
04a0: 66 75 63 74 69 6f 6e 20 70 6f 6c 6c 2e 65 64 69 fuction poll.edi
04b0: 74 20 28 73 68 6f 75 6c 64 20 62 65 20 69 6e 20 t (should be in
04c0: 63 6f 6e 74 72 6f 6c 2e 73 63 6d 29 2e 20 50 61 control.scm). Pa
04d0: 72 61 6d 65 74 65 72 20 73 65 74 20 69 73 20 27 rameter set is '
04e0: 69 64 20 74 6f 20 61 20 70 6f 6c 6c 20 6e 75 6d id to a poll num
04f0: 2e 0a 0a 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ...=============
0500: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0510: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0520: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0530: 3d 3d 3d 3d 3d 3d 3d 3d 3d 0a 34 2e 20 41 20 63 =========.4. A c
0540: 6f 6d 70 6c 65 78 20 6c 69 6e 6b 20 65 78 61 6d omplex link exam
0550: 70 6c 65 0a 0a 28 73 3a 61 20 22 52 65 70 6c 79 ple..(s:a "Reply
0560: 22 20 27 68 72 65 66 20 28 73 3a 6c 69 6e 6b 2d " 'href (s:link-
0570: 74 6f 20 28 73 3a 63 75 72 72 65 6e 74 2d 70 61 to (s:current-pa
0580: 67 65 29 20 0a 09 20 20 20 20 20 20 20 20 20 20 ge) ..
0590: 20 27 61 63 74 69 6f 6e 20 22 64 69 73 63 75 73 'action "discus
05a0: 73 69 6f 6e 2e 72 65 70 6c 79 22 20 3b 3b 20 3c sion.reply" ;; <
05b0: 70 61 67 65 3e 2e 3c 61 63 74 69 6f 6e 3e 0a 09 page>.<action>..
05c0: 20 20 20 20 20 20 20 20 20 20 20 27 72 65 70 6c 'repl
05d0: 79 5f 74 6f 20 28 6e 75 6d 62 65 72 2d 3e 73 74 y_to (number->st
05e0: 72 69 6e 67 20 28 68 61 73 68 2d 74 61 62 6c 65 ring (hash-table
05f0: 2d 72 65 66 20 72 6f 77 20 27 70 6f 73 74 73 2e -ref row 'posts.
0600: 69 64 29 29 20 0a 09 20 20 20 20 20 20 20 20 20 id)) ..
0610: 20 20 27 69 64 20 28 73 3a 67 65 74 20 22 64 69 'id (s:get "di
0620: 73 63 75 73 73 69 6f 6e 2e 70 61 72 65 6e 74 5f scussion.parent_
0630: 6f 62 6a 65 63 74 5f 69 64 22 29 29 20 22 72 65 object_id")) "re
0640: 70 6c 79 22 29 0a 0a 3b 3b 20 75 73 65 20 28 73 ply")..;; use (s
0650: 3a 67 65 74 2d 70 61 72 61 6d 20 74 6f 20 67 65 :get-param to ge
0660: 74 20 74 68 65 20 27 69 64 2c 20 6f 72 20 27 72 t the 'id, or 'r
0670: 65 70 6c 79 5f 74 6f 20 76 61 6c 75 65 73 0a 0a eply_to values..
0680: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0690: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
06a0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
06b0: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
06c0: 3d 3d 3d 3d 3d 3d 0a 35 2e 20 47 65 74 20 61 6e ======.5. Get an
06d0: 64 20 73 65 74 20 61 20 73 65 73 73 69 6f 6e 20 d set a session
06e0: 76 61 72 0a 0a 28 73 3a 73 65 73 73 69 6f 6e 2d var..(s:session-
06f0: 76 61 72 2d 67 65 74 20 22 6b 65 79 6e 61 6d 65 var-get "keyname
0700: 22 29 0a 28 73 3a 73 65 73 73 69 6f 6e 2d 76 61 ").(s:session-va
0710: 72 2d 73 65 74 21 20 22 6b 65 79 6e 61 6d 65 22 r-set! "keyname"
0720: 20 22 76 61 6c 75 65 22 29 0a 0a 35 2e 31 20 50 "value")..5.1 P
0730: 61 67 65 20 6c 6f 63 61 6c 20 76 61 72 73 0a 0a age local vars..
0740: 28 73 3a 73 65 74 21 20 6b 65 79 20 76 61 6c 29 (s:set! key val)
0750: 0a 28 73 3a 67 65 74 20 6b 65 79 29 0a 0a 3d 3d .(s:get key)..==
0760: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0770: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0780: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0790: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
07a0: 3d 3d 3d 3d 0a 36 2e 20 6d 61 6b 65 20 61 20 73 ====.6. make a s
07b0: 65 6c 65 63 74 69 6f 6e 20 64 72 6f 70 20 64 6f election drop do
07c0: 77 6e 0a 0a 49 6e 20 76 69 65 77 2e 73 63 6d 3a wn..In view.scm:
07d0: 20 0a 0a 28 73 3a 73 65 6c 65 63 74 20 27 28 28 ..(s:select '((
07e0: 22 57 6f 72 6c 64 22 20 30 29 28 22 43 6f 75 6e "World" 0)("Coun
07f0: 74 72 79 22 20 31 29 28 22 53 74 61 74 65 22 20 try" 1)("State"
0800: 32 29 28 22 54 6f 77 6e 2f 43 69 74 79 22 20 33 2)("Town/City" 3
0810: 29 29 20 27 6e 61 6d 65 20 27 73 63 6f 70 65 29 )) 'name 'scope)
0820: 0a 0a 49 6e 20 63 6f 6e 74 72 6f 6c 2e 73 63 6d ..In control.scm
0830: 3a 0a 0a 28 6c 65 74 20 28 28 73 63 6f 70 65 20 :..(let ((scope
0840: 28 73 3a 67 65 74 2d 69 6e 70 75 74 20 27 73 63 (s:get-input 'sc
0850: 6f 70 65 29 29 29 0a 20 20 2e 2e 2e 2e 0a 0a 3d ope))). ......=
0860: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0870: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0880: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0890: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
08a0: 3d 3d 3d 3d 3d 0a 37 2e 20 53 69 6d 70 6c 65 20 =====.7. Simple
08b0: 65 72 72 6f 72 20 72 65 70 6f 72 74 69 6e 67 0a error reporting.
08c0: 0a 49 6e 20 63 6f 6e 74 72 6f 6c 2e 73 63 6d 3a .In control.scm:
08d0: 0a 28 73 3a 73 65 74 2d 65 72 72 20 22 59 6f 75 .(s:set-err "You
08e0: 20 6d 75 73 74 20 70 72 6f 76 69 64 65 20 61 6e must provide an
08f0: 20 65 6d 61 69 6c 20 61 64 64 72 65 73 73 22 29 email address")
0900: 0a 0a 49 6e 20 76 69 65 77 2e 73 63 6d 3a 0a 28 ..In view.scm:.(
0910: 73 3a 67 65 74 2d 65 72 72 20 73 3a 65 72 72 2d s:get-err s:err-
0920: 66 6f 6e 74 29 0a 0a 4f 72 3a 0a 28 73 3a 67 65 font)..Or:.(s:ge
0930: 74 2d 65 72 72 20 28 6c 61 6d 62 64 61 20 28 78 t-err (lambda (x
0940: 29 28 73 3a 65 72 72 2d 66 6f 6e 74 20 78 20 28 )(s:err-font x (
0950: 73 3a 62 72 29 29 29 29 0a 0a 3d 3d 3d 3d 3d 3d s:br))))..======
0960: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0970: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0980: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0990: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
09a0: 0a 38 2e 20 4d 69 73 63 20 75 73 65 66 75 6c 20 .8. Misc useful
09b0: 73 74 75 66 66 0a 0a 20 20 69 2e 20 4c 61 7a 79 stuff.. i. Lazy
09c0: 2f 73 61 66 65 20 73 74 72 69 6e 67 2d 3e 6e 75 /safe string->nu
09d0: 6d 62 65 72 20 0a 0a 28 73 3a 61 6e 79 2d 3e 6e mber ..(s:any->n
09e0: 75 6d 62 65 72 20 76 61 6c 29 0a 0a 20 20 69 69 umber val).. ii
09f0: 2e 20 52 61 6e 64 6f 6d 20 73 74 72 69 6e 67 0a . Random string.
0a00: 0a 28 73 65 73 73 69 6f 6e 3a 6d 61 6b 65 2d 72 .(session:make-r
0a10: 61 6e 64 2d 73 74 72 69 6e 67 20 6c 65 6e 29 0a and-string len).
0a20: 0a 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d .===============
0a30: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0a40: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0a50: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0a60: 3d 3d 3d 3d 3d 3d 3d 0a 39 2e 20 46 6f 72 6d 73 =======.9. Forms
0a70: 20 61 6e 64 20 69 6e 70 75 74 0a 0a 28 73 3a 66 and input..(s:f
0a80: 6f 72 6d 20 27 61 63 74 69 6f 6e 20 22 6c 6f 67 orm 'action "log
0a90: 69 6e 2e 6c 6f 67 69 6e 22 20 27 6d 65 74 68 6f in.login" 'metho
0aa0: 64 20 22 70 6f 73 74 22 0a 20 20 20 28 73 3a 69 d "post". (s:i
0ab0: 6e 70 75 74 2d 70 72 65 73 65 72 76 65 20 27 74 nput-preserve 't
0ac0: 79 70 65 20 22 74 65 78 74 22 20 27 6e 61 6d 65 ype "text" 'name
0ad0: 20 22 65 6d 61 69 6c 2d 61 64 64 72 65 73 73 22 "email-address"
0ae0: 20 27 73 69 7a 65 20 22 31 36 22 20 27 6d 61 78 'size "16" 'max
0af0: 6c 65 6e 67 74 68 20 22 33 30 22 29 0a 20 20 20 length "30").
0b00: 28 73 3a 69 6e 70 75 74 20 27 74 79 70 65 20 22 (s:input 'type "
0b10: 73 75 62 6d 69 74 22 20 20 20 27 6e 61 6d 65 20 submit" 'name
0b20: 22 66 6f 72 6d 2d 6e 61 6d 65 22 20 27 76 61 6c "form-name" 'val
0b30: 75 65 20 22 6c 6f 67 69 6e 22 29 29 0a 0a 28 73 ue "login"))..(s
0b40: 3a 67 65 74 2d 69 6e 70 75 74 20 27 65 6d 61 69 :get-input 'emai
0b50: 6c 2d 61 64 64 72 65 73 73 29 0a 0a 3d 3d 3d 3d l-address)..====
0b60: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0b70: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0b80: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0b90: 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d 3d ================
0ba0: 3d 3d 0a 31 30 2e 20 0a 0a ==.10. ..