Initial version of "Howto"

























































































































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Gotchas!
=======

1. All items for a page *must* be part of a list!

   OK:     (list (function1 param1)(function2 param2))
   NOT OK: (begin (function1 param1)(function2 param2))


Various components
==================

======================================================================
1. Create a link.

(s:null "[" (s:a name 'href 
               (s:link-to (string-append "location/" (string-intersperse p "/") ""))) "] ")))

======================================================================
2. Call current page with new param

In view.scm:

 (s:center "[" (s:a 'href (s:link-to "polls"
                           'id
                            (begin
                              (poll:poll 'fill-polls)
                              (poll:poll 'get-next-poll)))
                          "Go to the next poll")  "]")

In control.scm:

(let ((poll-id (s:get-param 'id)))
 ;; do stuff based on poll-id

======================================================================
3. Call an action on a specific page

 (s:a 'href (s:link-to "polls" 'id (poll:poll 'get 'id) 
			       'action "poll.edit")
            "Suggest changes to this poll")

 NOT TRUE! This calls fuction poll.edit (should be in control.scm). Parameter set is 'id to a poll num.

======================================================================
4. A complex link example

(s:a "Reply" 'href (s:link-to (s:current-page) 
	           'action "discussion.reply" ;; <page>.<action>
	           'reply_to (number->string (hash-table-ref row 'posts.id)) 
	           'id (s:get "discussion.parent_object_id")) "reply")

;; use (s:get-param to get the 'id, or 'reply_to values

======================================================================
5. Get and set a session var

(s:session-var-get "keyname")
(s:session-var-set! "keyname" "value")

5.1 Page local vars

(s:set! key val)
(s:get key)

======================================================================
6. make a selection drop down

In view.scm: 

(s:select '(("World" 0)("Country" 1)("State" 2)("Town/City" 3)) 'name 'scope)

In control.scm:

(let ((scope (s:get-input 'scope)))
  ....

======================================================================
7. Simple error reporting

In control.scm:
(s:set-err "You must provide an email address")

In view.scm:
(s:get-err s:err-font)

Or:
(s:get-err (lambda (x)(s:err-font x (s:br))))

======================================================================
8. Misc useful stuff

  i. Lazy/safe string->number 

(s:any->number val)

  ii. Random string

(session:make-rand-string len)

 iii. string to number for pgint
 
(s:any->pgint val)

======================================================================
9. Forms and input

(s:form 'action "login.login" 'method "post"
   (s:input-preserve 'type "text" 'name "email-address" 'size "16" 'maxlength "30")
   (s:input 'type "submit"   'name "form-name" 'value "login"))

(s:get-input 'email-address)

To preserve the input simply do a set of the value on the 'name field:
(s:set! "email-address" "matt@kiatoa.com")

======================================================================
10.