[cl-who-devel] Building a table from a list of strings - Can't seem to get it right

[Jens Teich]

Bryan Emrys schrieb:
> Now I'm really confused. Ken's example does exactly what I want when I create a gridify function and call it from a page macro (defmacro templates at the bottom of the email). But if I put the function body into the page macro, (see second example), it doesn't work. Rather, it prints the entire table, complete with tr and td with no string - then drops the list of strings after the table
> Both use exactly the same macros to generate the page and it is a cut and paste job. Somehow putting the function body into the macro is changing how the loops work:
> 
> WORKS
> (defun gridify (x &optional (col 5))
>   "given a list of strings, put them in an html table (returned as a string) with |col| columns."
>   (with-html-output-to-string (var nil)
>     (:table
>       (loop for xp on x by (lambda (p) (nthcdr col p))
>         do (htm (:tr (loop for i upto (1- col) for (id name) in xp
>                        do (htm (:td (:a :href (format nil "~a~a" "countries-display?id=" id) (str name)))))))))))
> 
> (defpage-easy-slp gridify-countries "Countries Grid" "/gridify-countries" ()
>   (let* ((data-query "select id,name from countries order by name ")
> 	   (results (query data-query))
> 	   (col 5))
>     (gridify results col)))
> 
> DOESNT WORK
> 
> (defpage-easy-slp countries-grid "Countries Grid" "/countries-grid" ()
>   (let* ((data-query "select id,name from countries order by name ")
> 	 (x (query data-query))
> 	 (col 5)) 
>     (with-html-output-to-string (var nil)
> 	(:table
>           (loop for xp on x by (lambda (p) (nthcdr col p))
> 	    do (htm (:tr (loop for i upto (1- col) for (id name) in xp
> 			 do (htm (:td (:a :href (format nil "~a~a" "countries-display?id=" id) (str name))))))))))))
> 
> DEF MACROS
> 
> (defmacro page-template (title &body body)
>     `(with-html-output-to-string (*standard-output* nil :prologue t :indent t)
>     (:html
>       (:head
>        (:link :rel "stylesheet" :type "text/css" :href "/css/screen.css" :media "screen")
>       (:title (str (format nil " ~a" ,title))))
>       (:body
>        (:div :class "container"
>          (:div :class "column span-24"
> 	     (str , at body))))))))
> 
> (defmacro defpage-easy-slp (name title uri parameter-list &body body)
>     `(define-easy-handler (,name :uri ,uri 
>  			       :default-request-type :both)
>  	 ,parameter-list
>       (page-template ,title , at body)))

see http://lisp-univ-etc.blogspot.com/2009/03/cl-who-macros.html

Jens