write up:

For the second exploration I had the idea of parsing HTML from an existing site and hosting it remotely from racket. Well, I guess this was a good idea to try, but I did not successfully meet my goal, yet. The biggest problem I encountered while looking into the parsing of the HTML, is that the HTML library does not really provide any useful tools to converting it to x-expression. I then went to Google for some help and I found some promising code among others that said it the code would do what I needed, but it was slightly wrong. I first used read-html-as-xml to convert the code to XML to then convert to x-expression. This seemed promising and correct but when I Went to launch the code for the web server it looked like it only converted the head to proper x-expression. I then tried another conversion from the HTML library called html->xexpr, but again the results where not as expected. I have come to the conclusion right now that if I want to generate proper x-expression code to essentially imitate a page I need to read the HTML as plain text and parse it myself to convert it to a proper x-expression. This is something that I realized today after trying to make the XML/HTML libraries do what I want. Unfortunately, I don't think I can finish creating a custom HTML to x-expression parser for this exploration, but it is something I would like to integrate for the final project. I could use the knowledge I learned from this exploration to build a custom editor for HTML that allows you to test easily while developing or something with GUI. I viewed this exploration to be insightful and motivating. For this exploration I also looked into net/url, web-server/servlet, web-server/servlet-env, XML/HTML, and the brief exploration of and external library called planet neil/html-parsing:2:0 to test to see if it would parse it the way I wanted it to be parsed. The code below prints the contents of an html value passed as a list. It also contains functions for producing raw text of html and generating ports of paths and url's

I uploaded this under the FP1 on accident and just realize this now

Code:

lang racket ;to host a racket webserver (require web-server/servlet web-server/servlet-env ;parser for html html ;parser for xml xml ;get the url page content net/url ;prefix for html and xml (since syntax cn be confused within racket) (prefix-in h: html) (prefix-in x: xml) ;because the built in racket was garbage (planet neil/html-parsing:2:0))

;determines if the path for the file is windows or unix (file-url-path-convention-type)

;readable url for ports (define in-val (string->url "https://www.google.com/")) (define in-val1 (string->url "https://www.outdoored.com/jobs/summer-kayak-internship")) (define footest (string->url "http://localhost:8080/foo/testing")) (define xtest (path->url "C://Users//Emmy//Desktop//UML//newhtmltest.html")) ;(define in-path (relative-path->relative-url-string "C:\Users\Emmy\Desktop\UML\newhtmltest.html"))

;got this from ;http://stackoverflow.com/questions/28195841/how-to-extract-element-from-html-in-racket ;I found it seemingly difficult to use the html struct variables ;this doesnt even work as intended ;(define (read-html-as-xexpr in) ;since the value we want is contained in th 3rd values location ; (caddr (xml->xexpr ; (element #f #f 'root '() ;creates an element that has a root and '(), required cast ; (read-html-as-xml in)))))

;;closes port after information is extracted (define (read-url-port in) (call/input-url in ;the url get-pure-port ;port for first var read-html));function to be applied

;dynamically creates the response/xexpr for the host, ;with a passed xexpression ;variable to just test for now ;(define (port_to_string val) (port->lines (get-pure-port val))) ;(define test_pts (port_to_string in-val)) ;(define (make_prety var prev_char cur_token new_l) ; (if(equal? null prev_char) ; (cond((equal? prev_char null) ;(make_prety ;(substring var (- (string-length var) 1)) ; (string-ref var 0) ;; (string-append cur_token (string-ref var 0)) ; new_l)) ;; ((equal? prev_char #\ ; ((equal? (string-ref var 0) #>) ; (make_prety ; (substring var (- (string-length var) 1)) ; null ; null ; (append new_l (list (string-append cur_token ">"))))) ; ((equal? (string-ref var 0) #<) ; (display "error")) ; (else ; (make_prety ; (substring var (- (string-length var) 1)) ; prev_char

  ;((equal? (string-ref var 0) #\>) (make pretty (substring var          (make_prety (substring var 1 (- (string-length var) 1)) prev_char new_l))

; (if (equal?

;creates a value in xexpr for create a response/xexpr (define to_create_val (read-url-port in-val))

;test planet neil package to rest of html (define testneil (call/input-url in-val get-pure-port html->xexp))

;create a the xexpr to host the server for the test val (define (create-response-xexpr req) (response/xexpr to_create_val))

;hosts the webserver with the passesexpression (define (host-server read-port) (serve/servlet read-port))

;this last bit of code is something I am tying that simply reads and html and ;creates a list withall of its pcdata for content oftags. (define an-html (h:read-xhtml (open-input-string (string-append "

My title" " Hello world

Testing!

" "")))) ; extract-pcdata: html-content/c -> (listof string) ; Pulls out the pcdata strings from some-content. (define (extract-pcdata some-content) (cond [(x:pcdata? some-content) (list (x:pcdata-string some-content))] [(x:entity? some-content) (list (x:entity-text some-content))] [else (extract-pcdata-from-element some-content)]))

; extract-pcdata-from-element: html-element -> (listof string) ; Pulls out the pcdata strings from an-html-element. (define (extract-pcdata-from-element an-html-element) (match an-html-element [(struct h:html-full (attributes content)) (apply append (map extract-pcdata content))]

[(struct h:html-element (attributes)) (apply append (map extract-pcdata attributes))])) (printf "~s\n" (extract-pcdata an-html)) Status API Training Shop Blog About © 2015 GitHub, Inc. Terms Privacy Security Contact