|
rhoe (ρe)
|
```
my code is :
```scheme
`(html
(style ((type "text/css")) "table, th, td { border:1px solid black; }")
(head (title "Plot"))
(body (h1 "BepiColombo")
(p
(center
(br)
(table
(tr
(th ,(string-append physic " (" physic-greek4html ")")))
```
where `physic-greek4html` is `(regexp-replace #rx"rho" physic "\\ρ")`
how can i prevent `&` to be reinterpreted by the `xml` library of Racket?
i want only `ρ` in the html source code
Regards,
Damien
---
**Author:**  [@bakgatviooldoos](https://racket.discourse.group/u/bakgatviooldoos)\
**Post date:** [February 20, 2025, 1:56pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/2 "2025-02-20T13:56:24Z")
Hi, @damien_mattei!
I feel a bit ashamed of this, because I caved and asked Gippity what the deal was, but apparently this works:
```scheme
#lang racket/base
(require xml)
(define physic "rho")
(define physic-greek4html (entity #f #f 'rho))
(define html-code
`(html
(head (title "Plot"))
(body
(h1 "BepiColombo")
(p
(center
(table
(tr
(th ,physic " (",(xml->xexpr physic-greek4html)")"))))))))
(display (xexpr->string html-code))
```
```scheme
Plot
BepiColombo
```
So, I assume that because the object is now an entity, it is not being interpreted as an escapable string anymore and inserted as-is (entities are used as substitutions?). But that is about the extent of my understanding here.
* * *
Edit: lol, so you could also just write: `'rho` and it would be the same. Apologies for the misdirect.
```scheme
(define html-code
`(html
(head (title "Plot"))
(body
(h1 "BepiColombo")
(p
(center
(table
(tr
(th ,physic " (",'rho ")"))))))))
```
---
**Author:**  [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\
**Post date:** [February 20, 2025, 3:21pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/3 "2025-02-20T15:21:55Z")
Hello @bakgatviooldoos ,
i was going to post-reply my solution when i see your
i'm afraid to see Le Chat ( 🐈 we have in France an IA called like that ...) better than us ... hope only for technical things it is better to search the web with our own past solutions... (for algorithm i tested it and find it dumb....)
but yes your solution works.
Probably i'm misunderstanding between a lot in the xml library: xexpr,xml, entity.... not always clear for me.
But i found those working:
```scheme
(parameterize ([current-unescaped-tags (cons 'th html-unescaped-tags)]) (write-xexpr `(html (th ,(regexp-replace #rx"rho" physic "\\ρ")))))
ρe |
```
and this:
```scheme
(parameterize ([current-unescaped-tags (cons 'th html-unescaped-tags)]) (xexpr->string `(html (th ,(regexp-replace #rx"rho" physic "\\ρ")))))
"ρe | "
```
the only big problem with this is that my page has now no indentation in my html code page.
```scheme
;; create output HTML file
(define html-out (open-output-file #:exists 'truncate html-page-path))
(parameterize ([current-unescaped-tags (cons 'th html-unescaped-tags)]) ; escape table header from the rewrite of ampersand for example
;;(display-xml/content (xexpr->xml html-sexpr)
(write-xexpr html-sexpr
;;#:indentation 'classic
html-out))
(close-output-port html-out)
```
oh i understand now the caveat with the Gipity solution : it force me to almost code the page by hand ,changing everywhere i need the physic size by, hand, rho many times, theta many times and so on....
i prefer the solution with regex-replace and parametrize even if it is not elegant to change be applied to all (table header)
For now we are still a bit better than AI 🙂, but i would like to have a solution simpler, i never succeed too in using a method that allow classic indentation too.
> [@bakgatviooldoos](#):
>
> Edit: lol, so you could also just write: `'rho` and it would be the same. Apologies for the misdirect.
yes i find this solution too, usefull for static data but perheaps i think constructiong a complex solution ,splitting and parsing the physic size and generating a list L of text and 'rho etc and unquote splicing the list in the xexpr at the good place... but complex.....
---
**Author:**  [@bakgatviooldoos](https://racket.discourse.group/u/bakgatviooldoos)\
**Post date:** [February 20, 2025, 5:22pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/4 "2025-02-20T17:22:34Z")
> [@damien\_mattei](#):
>
> my page has now no indentation in my html code page.
I'm glad you came right. Perhaps if you display the `xexpr` after converting to XML first, using the utility procedure, `display-xml/content`?
```scheme
(with-output-to-file "test.html"
#:exists 'truncate/replace
(lambda ()
(display-xml/content
(xexpr->xml html-code)
#:indentation 'scan)))
```
This produces:
```scheme
Plot
BepiColombo
```
> [@damien\_mattei](#):
>
> i'm afraid to see Le Chat [...] better than us
Plenty of people better than I am, already 😉 Jokes aside, it's probably like my mom used to say about listening to "that little voice": as long as you don't ignore it too much, you'll know when you're being naughty and when it's okay err.
I can't remember if I had this thought, or if I appropriated it somewhere--likely the latter--but the LLMs seem to be a form of "tree of the knowledge of good and evil". It's not what it gives you (haha, you were naked all along), but what it takes away; which I think is a pretty neat analogy.
Anyways, no need to lose any _chatoyance_ yet, ey.
---
**Author:**  [@benknoble](https://racket.discourse.group/u/benknoble)\
**Post date:** [February 20, 2025, 5:59pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/5 "2025-02-20T17:59:53Z")
2 comments (I skimmed the thread).
1. Quasiquoting doesn't require unquoting to quote.
```
`(p ,'rho)
```
is equivalent to
```
`(p rho)
```
and avoids the `,'` sigil that might be confusing.
1. Racket's xexpr facilities do a lot of work to help you not hit footguns with injection. If you _really_ need to bypass them, the most reliable way I've found is `cdata`, but this should be considered a hack.
---
**Author:**  [@joeld](https://racket.discourse.group/u/joeld)\
**Post date:** [February 20, 2025, 8:21pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/6 "2025-02-20T20:21:04Z")
> [@damien\_mattei](#):
>
> the only big problem with this is that my page has now no indentation in my html code page.
Shameless plug, you may find my [HTML5 Printer package](https://docs.racket-lang.org/html-printer/index.html) useful. See also the section in the docs for that package, [Comparing with included Racket functions](https://docs.racket-lang.org/html-printer/index.html#(part._.Comparing_with_included_.Racket_functions)) — in particular, `display-xml/content` works most of the time, but its indentation may introduce extra whitespace in rendered HTML, and it doesn't wrap long lines.
---
**Author:**  [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\
**Post date:** [February 21, 2025, 6:05pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/7 "2025-02-21T18:05:58Z")
it's interesting because Gipitty got the good idea at last and i'm curious how you @bakgatviooldoos formulated it the question?
As long as i tried to modify the string myself the & char was escaped by the XML parser in the form of `&` , so the good idea was to use `'rho` instead of `ρ` in the string. This with `xml`or `html-printer` (@joeld )
I had to implement what i was saying:
```scheme
#! /usr/bin/env racket
#lang reader SRFI-105
...
(require Scheme+)
(require xml
(except-in 2htdp/batch-io xexpr?)) ; for: read-lines
(require html-printer)
;; convert physical size in latin string to greek characters
;; > (between '(1 2 3) 'A)
;; '(1 A 2 A 3)
;; > (between '(1 2) 'A)
;; '(1 A 2)
;; > (between '(1) 'A)
;; '(1)
(define (between L elem)
(if (null? (cdr L))
L
(cons (car L)
(cons elem
(between (cdr L) elem)))))
(define latin-rho "rho")
(define sp (string-split physic latin-rho #:trim? #f)) ;; example: (string-split "rhoe" "rho" #:trim? #f) ---> '("" "e")
(define xexpr-size (between sp 'rho))
(define xexpr-size-clean (remove "" xexpr-size))
;;{physic-greek <- (regexp-replace #rx"rho" physic "ρ")}
;;{physic-greek4html <- (regexp-replace #rx"rho" physic "\\ρ")}
(display "interpole_fields : physic-greek4html=") (display physic-greek4html) (newline)
....
;; generate HTML page
{html-sexpr <- `(html
(style ((type "text/css")) "table, th, td { border:1px solid black; }")
(head (title "Plot"))
(body (h1 "BepiColombo")
(p
(center
(br)
(table
(tr
;;(th ,(string-append physic " (" physic-greek4html ")")))
(th ,(string-append physic " (" )
,@xexpr-size-clean
")" ))
(tr
(th ,math))
(tr
(td ,data-cube-filename))
(tr
(td ,basename-trajectory-xml))
(tr
(td ,output-file)))
(br)
(br)
(img ((src ,image-name)))
(br)
(br)
(img ((src ,image-name-distance)))))))}
;; create output HTML file
(define html-out (open-output-file #:exists 'truncate html-page-path))
(display "interpole_fields : html-sexpr=") (display html-sexpr) (newline)
;; (write-xexpr html-sexpr
;; html-out)
;;(parameterize ([current-unescaped-tags (cons 'th html-unescaped-tags)]) ; escape table header from the rewrite of ampersand for example
;; (display-xml/content (xexpr->xml html-sexpr)
;; html-out
;; #:indentation 'classic)
;;)
(write (xexpr->html5 html-sexpr)
html-out)
(close-output-port html-out)
```
as you can see in code i tested 3 solutions with: `write-xexpr`, `display-xml/content (xexpr->xml html-sexpr)` and `xexpr->html5`
in any cas my xexpr (?) is:
```scheme
html-sexpr=(html (style ((type text/css)) table, th, td { border:1px solid black; }) (head (title Plot)) (body (h1 BepiColombo) (p (center (br) (table (tr (th rhoe ( rho e ))) (tr (th SCALARS)) (tr (td Data/Dipole3D_rhoe0_6000.vtk)) (tr (td V504EwE.xml)) (tr (td trajectory-near_Mio_rhoe_6000.txt))) (br) (br) (img ((src V504EwE.jpeg))) (br) (br) (img ((src V504EwE-distance.jpeg)))))))
```
the display of `rho`is as expected for all but `display-xml/content` add a space :
not is it with others:
and only indentation in html code is possible with `display-xml/content`
i was not able to get a correct web page with `xexpr->html5` :
i did not know what happened ....
long the way is to write html page in Racket 😅
will use the one liner page html code version (nobody will check it ) that display better:
---
**Author:**  [@bakgatviooldoos](https://racket.discourse.group/u/bakgatviooldoos)\
**Post date:** [February 22, 2025, 7:59pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/8 "2025-02-22T19:59:13Z")
> [@damien\_mattei](#):
>
> i'm curious how you @bakgatviooldoos formulated it the question?
Very plainly, as you'll see. You'll also note it gave a _slightly off_ answer, but I could infer what it meant, so this feels nit-picky to mention.
> **[ChatGPT](https://chatgpt.com/share/67ba2bd9-b448-8010-839c-a2cf1064453d)**
>
> ChatGPT helps you get answers, find inspiration, and be more productive.
---
**Author:**  [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\
**Post date:** [February 23, 2025, 6:44am UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/9 "2025-02-23T06:44:46Z")
> [@bakgatviooldoos](#):
>
> Very plainly, as you'll see. You'll also note it gave a _slightly off_ answer, but I could infer what it meant, so this feels nit-picky to mention.
yes ,chatgpt is great to find answers in the good direction , but seems fuzzy about precision,need little corrections (about exact syntax for example).
thank you , i will try the solution also with CDATA that @benknoble mentioned and which is explained by GPT
---
**Author:**  [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\
**Post date:** [February 23, 2025, 9:23am UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/10 "2025-02-23T09:23:26Z")
> [@benknoble](#):
>
> Racket's xexpr facilities do a lot of work to help you not hit footguns with injection. If you _really_ need to bypass them, the most reliable way I've found is `cdata`, but this should be considered a hack.
but it is sometimes more easy for little special portion of HTML code to generate it with strings,the hard point was to find doc for CDATA :
```scheme
,(make-cdata #f #f
(string-append physic " (" physic-greek4html-sup ")"))
```
[https://docs.racket-lang.org/xml/index.html#(def.\_((lib.\_xml%2Fmain..rkt).\_make-cdata))](https://docs.racket-lang.org/xml/index.html#%28def._%28%28lib._xml%2Fmain..rkt%29._make-cdata%29%29)
i did not understand why i had to add #f #f as parameters, doc is not clear on that, anyway i personally have a lot of problem to understand the Racket docs the way doc are presented, i remembered C doc under Linux in man pages being more understandable.
Again chatGPT was very fuzzy and wrong in how to use CDATA:
> **[ChatGPT - Racket CDATA Example](https://chatgpt.com/share/67bae572-84dc-8001-8bc0-dab951e2741c)**
>
> Shared via ChatGPT
CDATA made easy the transformation of e- in the physic value:
```scheme
(define latin-rho "rho")
(define sp (string-split physic latin-rho #:trim? #f)) ;; example: (string-split "rhoe" "rho" #:trim? #f) ---> '("" "e")
(define xexpr-size (between sp 'rho))
(define xexpr-size-clean (remove "" xexpr-size))
{physic-greek <- (regexp-replace #rx"rho" physic "ρ")}
{physic-greek-sup <- (regexp-replace #rx"e" physic-greek "e⁻")}
{physic-greek4html <- (regexp-replace #rx"rho" physic "\\ρ")}
{physic-greek4html-sup <- (regexp-replace #rx"e" physic-greek4html "e-")}
```
even if it could have be possible to create the `sup` html tag with code (using a `between` procedure enhanced) replacing in a string was easier.
For the extra space i find the solution chainging indentation from 'classic to 'scan but i think it is a bug because indentation style should not have added extra space.
```scheme
(display-xml/content (xexpr->xml html-sexpr)
html-out
#:indentation 'scan
;;'classic
)
```
and now the code is well indented:
---
**Author:**  [@joeld](https://racket.discourse.group/u/joeld)\
**Post date:** [February 23, 2025, 4:59pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/11 "2025-02-23T16:59:06Z")
> [@damien\_mattei](#):
>
> For the extra space i find the solution chainging indentation from 'classic to 'scan but i think it is a bug because indentation style should not have added extra space.
From [the last part of the documentation for `display-xml/content`](https://docs.racket-lang.org/xml/index.html#%28def._%28%28lib._xml%2Fmain..rkt%29._display-xml%2Fcontent%29%29):
> Be warned that even 'scan does not handle HTML with 100% accuracy. The following example will be incorrectly rendered as "no body" instead of "nobody":
>
> Examples:
>
> ```
> (define html-data '(span (i "no") (b "body")))
> (show 'scan html-data)
>
> no
> body
>
>
> ```
This is why `xexpr->html5` is better for HTML strings.
---
**Author:**  [@joeld](https://racket.discourse.group/u/joeld)\
**Post date:** [February 23, 2025, 5:12pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/12 "2025-02-23T17:12:13Z")
> [@damien\_mattei](#):
>
> i was not able to get a correct web page with `xexpr->html5` :
If you could give a minimal/simple example of the problem that runs in `#lang racket` and shows the input X-expression and the output HTML string, I would be able to determine if it was a problem with my library. A screenshot of the browser output isn’t enough to go on. I made several attempts to reconstruct something using your supplied code but there were too many missing bindings.
---
**Author:**  [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\
**Post date:** [February 23, 2025, 6:42pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/13 "2025-02-23T18:42:44Z")
there seems perheaps just all those \n causing problem....
i have not now the development host where all the code is but i succeeded with the info in discourse in reproducing the generated string of html on my current host:
```scheme
> (define xexpr `(html
(style ((type "text/css")) "table, th, td { border:1px solid black; }")
(head (title "Plot"))
(body (h1 "BepiColombo")
(p
(center
(br)
(table
(tr
;;(th ,(string-append physic " (" physic-greek4html ")")))
(th "blabla" ))
(tr
(th "SCALARS"))
(tr
(td "data-cube-filename"))
(tr
(td "basename-trajectory-xml"))
(tr
(td "output-file")))
(br)
(br)
(img ((src "image-name")))
(br)
(br)
(img ((src "image-name-distance"))))))))
(define xexpr
`(html
(style ((type "text/css")) "table, th, td { border:1px solid black; }")
(head (title "Plot"))
(body
(h1 "BepiColombo")
(p
(center
(br)
(table
(tr (th "blabla"))
(tr (th "SCALARS"))
(tr (td "data-cube-filename"))
(tr (td "basename-trajectory-xml"))
(tr (td "output-file")))
(br)
(br)
(img ((src "image-name")))
(br)
(br)
(img ((src "image-name-distance"))))))))
#
> (require html-printer)
(require html-printer)
standard-module-name-resolver: collection not found
for module path: html-printer
collection: "html-printer"
in collection directories:
/home/mattei/.local/share/racket/8.14/collects
/home/mattei/racket/collects/
... [176 additional linked and package directories] in: html-printer
packages that provide the missing module: .
html-printer .
> (require html-printer)
(require html-printer)
#
> (write (xexpr->html5 xexpr))
(write (xexpr->html5 xexpr))
"\n\n \n \n Plot\n \n \n BepiColombo
\n
\n \n \n | blabla | \n
\n \n | SCALARS | \n
\n \n | data-cube-filename | \n
\n \n | basename-trajectory-xml | \n
\n \n | output-file | \n
\n
\n
\n
\n ![](\"image-name\")
\n
\n ![](\"image-name-distance\")
\n \n\n"
```
as i'm using my #lang SRFI-105 parser, i make it again below with #lang racket but i suppose it will be the same :
```scheme
#lang racket
(require html-printer)
(define xexpr `(html
(style ((type "text/css")) "table, th, td { border:1px solid black; }")
(head (title "Plot"))
(body (h1 "BepiColombo")
(p
(center
(br)
(table
(tr
;;(th ,(string-append physic " (" physic-greek4html ")")))
(th "blabla" ))
(tr
(th "SCALARS"))
(tr
(td "data-cube-filename"))
(tr
(td "basename-trajectory-xml"))
(tr
(td "output-file")))
(br)
(br)
(img ((src "image-name")))
(br)
(br)
(img ((src "image-name-distance"))))))))
(write (xexpr->html5 xexpr))
```
---
**Author:**  [@joeld](https://racket.discourse.group/u/joeld)\
**Post date:** [February 23, 2025, 6:58pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/14 "2025-02-23T18:58:13Z")
If it's just that you don't want literal `\n` in your output string, you should use `display` instead of `write` in the last expression. `write` prints the value the way it would be written in Racket code (that is, “in such a way that instances of core datatypes can be read back in [using racket’s default reader]” per the docs).
---
**Author:**  [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\
**Post date:** [February 23, 2025, 7:28pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/15 "2025-02-23T19:28:23Z")
ok 😅
```scheme
(display (xexpr->html5 xexpr))
```
```scheme
Plot
BepiColombo
| blabla |
| SCALARS |
| data-cube-filename |
| basename-trajectory-xml |
| output-file |
>
```
i will test that in real life tomorrow...
thank
---
**Author:**  [@joeld](https://racket.discourse.group/u/joeld)\
**Post date:** [February 23, 2025, 10:01pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/16 "2025-02-23T22:01:50Z")
I've pushed a fix for that indent issue with that `
` tag following `
`.
---
**Author:**  [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\
**Post date:** [February 23, 2025, 11:01pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/17 "2025-02-23T23:01:52Z")
ah, i did not have noticed the mis-indent `
**Author:**  [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\
**Post date:** [February 24, 2025, 5:07pm UTC](https://racket.discourse.group/t/html-generating-xml-library-reinterpreting/3575/18 "2025-02-24T17:07:12Z")
with `display` this was ok now:
