Index: doc/howto.txt
==================================================================
--- doc/howto.txt
+++ doc/howto.txt
@@ -1,32 +1,35 @@
 Gotchas!
 =======
 
-1. All items for a page *must* be part of a list!
+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
-==================
+~~~~~~~~~~~~~~~~~~
 
 The URL:
 
 http://the.domain.com/pagename/p1/p2/p3?param1=value1
 
 (s:get-page-params) => '("p1" "p2")
 
 
-======================================================================
-1. Create a link.
+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
+
+
+Call current page with new param
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 In view.scm:
 
  (s:center "[" (s:a 'href (s:link-to "polls"
                            'id
@@ -38,42 +41,46 @@
 In control.scm:
 
 (let ((poll-id (s:get-param 'id)))
  ;; do stuff based on poll-id
 
-======================================================================
-3. Call an action on a specific page
+
+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
+
+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
+
+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
+
+make a selection drop down
+~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 In view.scm: 
 
 (s:select '(("World" 0)("Country" 1)("State" 2)("Town/City" 3)) 'name 'scope)
 
@@ -80,12 +87,13 @@
 In control.scm:
 
 (let ((scope (s:get-input 'scope)))
   ....
 
-======================================================================
-7. Simple error reporting
+
+Simple error reporting
+~~~~~~~~~~~~~~~~~~~~~~
 
 In control.scm:
 (s:set-err "You must provide an email address")
 
 In view.scm:
@@ -92,12 +100,26 @@
 (s:get-err s:err-font)
 
 Or:
 (s:get-err (lambda (x)(s:err-font x (s:br))))
 
-======================================================================
-8. Misc useful stuff
+
+Sharing data between pages
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+NOTE: This data is *not* preserved between cgi calls.
+
+;; In first page called
+(s:shared-set! "somekey" somevalue)
+
+;; In a page called later
+(let ((dat (s:shared-get "somekey")))
+  ( .... ))
+
+
+Misc useful stuff
+~~~~~~~~~~~~~~~~~
 
   i. Lazy/safe string->number 
 
 (s:any->number val)
 
@@ -107,12 +129,13 @@
 
  iii. string to number for pgint
  
 (s:any->pgint val)
 
-======================================================================
-9. Forms and input
+
+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"))
 
@@ -119,8 +142,5 @@
 (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. 
-

Index: setup.scm
==================================================================
--- setup.scm
+++ setup.scm
@@ -85,19 +85,31 @@
 ;; utility to get all vars as hash table
 (define (s:session-get-sessionvars)
   (sdat-get-sessionvars s:session))
 
 ;; inputs
+;;
 (define (s:get-input key)
   (session:get-input s:session key))
 
 (define (s:load-model model)
   (session:load-model s:session model))
 
 (define (s:model-path model)
   (session:model-path s:session model))
 
+;; share data between pages calls
+;;
+(define (s:shared-hash)
+  (sdat-get-shared-hash s:session))
+
+(define (s:shared-set! key val)
+  (hash-table-set! (sdat-get-shared-hash s:session) key val))
+
+(define (s:shared-get key)
+  (hash-table-ref (sdat-get-shared-hash s:session) key))
+
 ;; http://foo.bar.com/pagename/p1/p2 => '("p1" "p2")
 ;;
 (define (s:get-page-params)
   (sdat-get-page-params s:session))
 

Index: sugar.scm
==================================================================
--- sugar.scm
+++ sugar.scm
@@ -22,18 +22,83 @@
 ;; (define-syntax s:if-test
 ;;   (syntax-rules ()
 ;;     [(_ s x) (if   (string=? "yep" s)   x (list "s:if not"))]
 ;;     [(_ s x y) (if (string=? "yep" s) x y)]))
 
-
-(define-macro (s:if-param varname . dat)
-  (match dat
-	 (()    '())
-	 ((a)    `(if (s:get ,varname) ,a '()))
-	 ((a b)  `(if (s:get ,varname) ,a ,b))))
-
-(define-macro (s:if-sessionvar varname . dat)
-  (match dat
-	 (()    '())
-	 ((a)    `(if (s:session-var-get ,varname) ,a '()))
-	 ((a b)  `(if (s:session-var-get ,varname) ,a ,b))))
-
+;; Some of these routines use:
+;;
+;;     http://www.cs.toronto.edu/~gfb/scheme/simple-macros.html
+;;
+;; Syntax for defining macros in a simple style similar to function definiton,
+;;  when there is a single pattern for the argument list and there are no keywords.
+;;
+;; (define-simple-syntax (name arg ...) body ...)
+;;
+
+(define-syntax define-simple-syntax
+  (syntax-rules ()
+    ((_ (name arg ...) body ...)
+     (define-syntax name (syntax-rules () ((name arg ...) (begin body ...)))))))
+
+;;======================================================================
+;; syntatic sugar items
+;;======================================================================
+
+;; We often seem to want to include stuff if a conditional is met
+;; otherwise not include it. This routine makes that slightly cleaner
+;; since using a pure if results in #<undefined> objects. (admittedly they 
+;; should be ignored but this is slightly cleaner I think). 
+;;
+;; NOTE: This has to be a macro or the true clause will be evaluated 
+;; whether "a" is true or false
+
+;; If a is true return b, else return '()
+(define-simple-syntax (s:if a b)
+  (if a b '()))
+
+
+;; Using the Simple-Syntax System
+;; 
+;; The syntax for defining macros in this system is similar to that for defining functions. In fact if the macro has a fixed number of arguments the syntax is identical. For example:
+;; 
+;;   ; Define a simple macro to add a value to a variable.
+;;   ;
+;;   (define-simple-syntax (+= variable value)
+;;     (set! variable (+ variable value)))
+;; 
+;;   ; Use it.
+;;   ;
+;;   (define v 2)
+;;   (+= v 7)
+;;   v ; => 9
+;; 
+;; For a fixed number of arguments followed by an unknown number of arguments we use ... after a single argument to represent the unknown number (possibly zero) of arguments. For example, let's revise our definition of += to allow zero or more values to be added:
+;; 
+;;   ; Define a simple macro to add a zero or more values to a variable
+;;   ;
+;;   (define-simple-syntax (+= variable value ...)
+;;     (set! variable (+ variable value ...)))
+;; 
+;;   ; Use it
+;;   ;
+;;   (define v 2)
+;;   (+= v 7)
+;;   v ; => 9
+;;   (+= v 3 4)
+;;   v ; => 16
+;;   (+= v)
+;;   v ; => 16
+;; 
+
+
+;; (define-macro (s:if-param varname . dat)
+;;   (match dat
+;; 	 (()    '())
+;; 	 ((a)    `(if (s:get ,varname) ,a '()))
+;; 	 ((a b)  `(if (s:get ,varname) ,a ,b))))
+;; 
+;; (define-macro (s:if-sessionvar varname . dat)
+;;   (match dat
+;; 	 (()    '())
+;; 	 ((a)    `(if (s:session-var-get ,varname) ,a '()))
+;; 	 ((a b)  `(if (s:session-var-get ,varname) ,a ,b))))
+;;