# Format for multimedia files? **URL:** \ **Category:** Questions & Answers\ **Tags:** question, drracket\ **Created:** [November 28, 2024, 12:18am UTC](https://racket.discourse.group/t/format-for-multimedia-files/3365 "2024-11-28T00:18:18Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![ToddOBryan](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/toddobryan/32/1962_2.png) [@ToddOBryan](https://racket.discourse.group/u/ToddOBryan)\ **Post date:** [November 28, 2024, 12:18am UTC](https://racket.discourse.group/t/format-for-multimedia-files/3365/1 "2024-11-28T00:18:18Z")
Where is the description of what the format for multimedia files is? A lot of my early assignments include images and I'd like to be able to look at student text inside the files for analysis and grading. ---
**Author:** ![cadence](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/cadence/32/998_2.png) [@cadence](https://racket.discourse.group/u/cadence)\ **Post date:** [November 28, 2024, 1:04am UTC](https://racket.discourse.group/t/format-for-multimedia-files/3365/2 "2024-11-28T01:04:17Z")
I can't speak for the file format, but if you want to see the text, it's probably easiest to do so by opening the file in DrRacket and looking at it. ---
**Author:** ![ToddOBryan](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/toddobryan/32/1962_2.png) [@ToddOBryan](https://racket.discourse.group/u/ToddOBryan)\ **Post date:** [November 28, 2024, 9:06pm UTC](https://racket.discourse.group/t/format-for-multimedia-files/3365/3 "2024-11-28T21:06:53Z")
Yeah. I want to programmatically look at the file. ---
**Author:** ![soegaard](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/soegaard/32/19_2.png) [@soegaard](https://racket.discourse.group/u/soegaard)\ **Post date:** [November 28, 2024, 10:35pm UTC](https://racket.discourse.group/t/format-for-multimedia-files/3365/4 "2024-11-28T22:35:11Z")
The format is called WXME. [https://docs.racket-lang.org/gui/WXME\_Decoding.html](https://docs.racket-lang.org/gui/WXME_Decoding.html) It's extensible in the sense that snips (see snip%) can define how they are read and written. So, you might need to look at the documentation/code of the snips that are in your file too. ---
**Author:** ![blerner](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@blerner](https://racket.discourse.group/u/blerner)\ **Post date:** [December 1, 2024, 2:55pm UTC](https://racket.discourse.group/t/format-for-multimedia-files/3365/5 "2024-12-01T14:55:37Z")
The simplest way I know of to get _nearly_ the plain-text content of a WXME file is to (1) create a `text%`, (2) load the file into it, and (3) `send the-text% get-text` to get its content. I say "nearly" because this will render any embedded snips as `.`, which is not quite accurate and won't parse back in as valid student code, but is also likely good enough for text-processing. ```scheme (require racket/gui/base) (define (file->text filename) (define txt (new text%)) (send txt load-file filename) (send txt get-text)) ``` If you need to do more detailed processing, you'll need to actually walk the snip% tree, which is somewhat more tedious. Instead of sending `get-text`, you'll send `find-first-snip` (and send _that_ `next` to get its siblings), and then use `is-a?` on all the various snip classes you want to handle. I've used the following (believe it or not, edited somewhat for brevity! helper functions not included) ```scheme ;; display-all : (or/c snip? #f) output-port? -> #f ;; Walks the given snip tree and renders it as plaintext to the given output port. (define (display-all snip out #:inline-numbers? [inline-numbers? #f]) (if (not snip) out (let ((snip-name (send (send snip get-snipclass) get-classname))) (cond [(is-a? snip string-snip%) (display (send snip get-text 0 (send snip get-count)) out)] [(is-a? snip comment-box:snip%) (define comment (open-output-bytes)) (define contents (display-all (send (send snip get-editor) find-first-snip) comment)) (display (add-comment (get-output-string comment)) out)] [(equal? snip-name "(lib \"number-snip.ss\" \"drscheme\" \"private\")") (define val (number->string (send snip get-number))) (display (if inline-numbers? val (add-number val)) out)] [(or (is-a? snip xml-snip<%>) (equal? snip-name "(lib \"xml-snipclass.ss\" \"xml\")") (equal? snip-name "(lib \"xml-snipclass.rkt\" \"xml\")") (equal? snip-name "(lib \"xml.ss\" \"wxme\")")) (define xml (open-output-bytes)) (define contents (display-all (send (send snip get-editor) find-first-snip) xml)) (display (add-xml (get-output-string xml)) out)] [(or (equal? snip-name "(lib \"text-snipclass.ss\" \"xml\")") (equal? snip-name "(lib \"text-snipclass.rkt\" \"xml\")") (equal? snip-name "(lib \"text.ss\" \"wxme\")")) (define text (open-output-bytes)) (define contents (display-all (send (send snip get-editor) find-first-snip) text)) (display (add-text (get-output-string text)) out)] [(equal? snip-name (format "~s" '((lib "collapsed-snipclass.ss" "framework") (lib "collapsed-snipclass-wxme.ss" "framework")))) ;; Display collapsed-snips in collapsed form isn't good for grading: ;; it hides code, and could hide badly long lines. So, ;; expand the snip to its hidden pieces, instead. (for ([kid (in-list (send snip get-saved-snips))]) (display-all kid out))] [(or (is-a? snip scheme-snip<%>) (equal? snip-name "(lib \"scheme-snipclass.ss\" \"xml\")") (equal? snip-name "(lib \"scheme-snipclass.rkt\" \"xml\")") (equal? snip-name "(lib \"scheme.ss\" \"wxme\")")) (define rkt (open-output-bytes)) (define contents (display-all (send (send snip get-editor) find-first-snip) rkt)) (if (send snip get-splice?) (display (add-splice (get-output-string rkt)) out) (display (add-racket (get-output-string rkt)) out))] [(convertible? snip) (define bm (new bitmap-dc% [bitmap (make-object bitmap% 1 1)])) (define width (box 0)) (define height (box 0)) (send snip get-extent bm 0 0 width height) (if (or (= (unbox width) 0) (= (unbox height) 0)) (display (add-empty-image "") out) (with-handlers ([exn:fail:contract? (λ(e) (display (add-comment (string-append "Could not render this content;\n" "please contact a professor.")) out))]) (display (add-image (convert snip 'png-bytes)) out)))] [(syntax? snip) (display (syntax->datum snip) out)] [else (display (format ">?>~a>>~a<<<" snip) out)] ) (display-all (send snip next) out #:inline-numbers? inline-numbers?)))) ``` (I'd love to know if there are ways to detect number, xml, collapsed and scheme snips without resorting to snip classnames! But this code has worked well for me for years.)