The HTML Library

1. Use the function make-html-page (defined in hwk3-lib.ss) to create an html-page.

   make-html-page consumes three things: a string for the page title, a color for the page background, and a list of html-objects to display on the page. There are several kinds of html-object, and the data definition at the end of this document lists these.

   Example: If I want to create a web page containing my name and a link to the COMP 210 home page, I can write

        (define kathi-page
           (make-html-page 
            "My Page" 
            "WHITE"
            (cons (make-html-paragraph (cons "Kathi" empty))
                  (cons (make-html-link "http://www.cs.owlnet.rice.edu/~comp210/"
                                        "The COMP 210 Home Page")
                        empty)))
        

   See the data definitions below for an explanations of the other make-html-... functions.

2. Use the function html-to-file (also defined in the library) to write the page into a file.

   To see the html that the above example generates, set the library to hwk3-lib.ss and type the following:

        (html-to-file kathi-page "210test.html")
        

   This creates a file 210test.html in your working directory. You can view this file in your favorite browser.

Example: If I want a page containing a list of the names of the 210 instructors, I can write

(define instructor-page
   (make-html-page
    "Instructors"
    "YELLOW"
    (cons (make-html-list
           (cons "Kathi"
                 (cons "John"
                        (cons "Geraldine"
                              (cons "Philippe" empty))))
           false)
          empty))

• html-to-file : html-page string -> boolean
  Consumes an html-page structure and writes the html for that structure into the file named by the string. Always returns true.

• produce-test-page : html-object string -> boolean
  Writes a page containing only the given html-object to the given filename. Always returns true.

• produce-test-page/list : list-of-html-object string -> boolean
  Writes a page containing only the given html-objects to the given filename. Always returns true.

• filename-for-stock : stock -> string
  Consumes a stock and returns a filename for that stock's web page.

• category-filename : symbol -> string
  Consumes a category name and returns a string the name followed by ".html".

;; THE HTML STRUCTURES


(define-struct html-list (items numbered?))
(define-struct html-paragraph (contents))


(define-struct html-link (URL text))


(define-struct html-page (title bgcolor contents))

;; THE HTML DATA DEFINITION

;; An html-color is one of
;;      - "WHITE"
;;      - "BLUE"
;;      - "RED"
;;      - "YELLOW"
;;      - "GREEN"

;; An html-atom is one of
;;	- a string
;;	- a symbol
;;	- a number

;; A list of html-atoms (lo-html-atoms) is iether
;;	- empty, or
;;	- (cons a loha) 
;;		where a is an html-atom and
;;		      loha is a list of html atoms

;; An html-object is one of
;;

;;	- an html-atom

;;	- (make-html-list items numbered?)
;;		where items is a lo-html-objects and 
;;		      numbered? is a boolean

;;	- (make-html-paragraph contents)
;;		where contents is a lo-html-objects

;;	- (make-html-link URL text)
;;		where URL is a string and
;;		      text is an html-atom

;; A list of html-objects (lo-html-objects) is either
;;	- empty, or
;;	- (cons obj loh)
;;		where obj is an html-object and
;;		      loh is a lo-html-objects

;; An html-page is a structure
;;	(make-html-page title bg contents)
;; where title is a string,
;;       bg is an html-color, and
;;	 contents is a lo-html-objects