Issue with multiline string variable for JavaScript source code blocks

Issue with multiline string variable for JavaScript source code blocks

[Peter Moresi]

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Hi,

I'm found a bug in ob-js.el when passing multi-line strings into a
JavaScript source code blocks.

The attached org file describes the problem and fix that I'm using to work
around the issue.

Thanks,
Peter

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#+TITLE: Bug in multiline strings in ob-js.el

This org-mode file describes a bug in ob-js.el and proposes a solution.

* Problem Description
Let's say I have a multi-line string stored in an example block.

I want to store my CSV in an example block.

#+NAME: my-csv-data
#+BEGIN_EXAMPLE
  ColA,ColB,ColC
  1,2,3
  4,5,6
#+END_EXAMPLE

I have a JavaScript function that accepts a string named 'csv' and passing in 'my-csv-data'.

#+BEGIN_SRC js :var csv=my-csv-data :results output
  console.log(csv);
#+END_SRC

When I expand the source block I end up with:

#+BEGIN_SRC js
var csv="ColA,ColB,ColC
  1,2,3
  4,5,6";
console.log(csv);
#+END_SRC

This will not execute correctly because JavaScript does not support newlines in strings.

What I want instead is:

#+BEGIN_SRC js
  var csv="ColA,ColB,ColC\n  1,2,3\n  4,5,6";
  console.log(csv);
#+END_SRC

* Proposed Fix

  To fix this problem I changed function "org-babel-js-var-to-js" in ob-js.el:116.

  #+BEGIN_SRC emacs-lisp
    (defun org-babel-js-var-to-js (var)
      "Convert VAR into a js variable.
    Convert an elisp value into a string of js source code
    specifying a variable of the same value."
      (if (listp var)
          (concat "[" (mapconcat #'org-babel-js-var-to-js var ", ") "]")
        (format "%S" var)))
  #+END_SRC

  to

  #+BEGIN_SRC emacs-lisp
    (defun org-babel-js-var-to-js (var)
      "Convert VAR into a js variable.
    Convert an elisp value into a string of js source code
    specifying a variable of the same value."
      (if (listp var)
          (concat "[" (mapconcat #'org-babel-js-var-to-js var ", ") "]")
        (replace-regexp-in-string "\n" "\\\\n" (format "%S" var))))
  #+END_SRC

Re: Issue with multiline string variable for JavaScript source code blocks

[Nicolas Goaziou]

Hello,

Peter Moresi <peter.moresi@gmail.com> writes:

> I'm found a bug in ob-js.el when passing multi-line strings into a
> JavaScript source code blocks.

Thanks for your report.

> The attached org file describes the problem and fix that I'm using to work
> around the issue.

Would you mind providing a patch for that? See 

              http://orgmode.org/worg/org-contribute.html

if you're interested.


Regards,

-- 
Nicolas Goaziou

Re: Issue with multiline string variable for JavaScript source code blocks

[Peter Moresi]

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Sure, the patch is attached.​

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[-- Attachment #2: 0001-Fix-problem-passing-multiline-variables-into-JS-sour.patch --]
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From 2c8214a8e45a6368c709ae26d6d20c7458ebe0dd Mon Sep 17 00:00:00 2001
From: Peter Moresi <peter.moresi@pnmac.com>
Date: Tue, 18 Nov 2014 15:58:17 -0800
Subject: [PATCH] Fix problem passing multiline variables into JS source code
 block

---
 lisp/ob-js.el |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/ob-js.el b/lisp/ob-js.el
index 47355b3..1a95216 100644
--- a/lisp/ob-js.el
+++ b/lisp/ob-js.el
@@ -114,7 +114,7 @@ Convert an elisp value into a string of js source code
 specifying a variable of the same value."
   (if (listp var)
       (concat "[" (mapconcat #'org-babel-js-var-to-js var ", ") "]")
-    (format "%S" var)))
+        (replace-regexp-in-string "\n" "\\\\n" (format "%S" var))))
 
 (defun org-babel-prep-session:js (session params)
   "Prepare SESSION according to the header arguments specified in PARAMS."
-- 
1.7.10.4

Re: Issue with multiline string variable for JavaScript source code blocks

[Nicolas Goaziou]

Hello,

Peter Moresi <peter.moresi@gmail.com> writes:

> Sure, the patch is attached.​

Applied. Thank you.

However I had to fill your commit message, which was incomplete. For
reference, here is what I used, from your initial report:

--8<---------------cut here---------------start------------->8---
ob-js: Fix passing multiline variables

* lisp/ob-js.el (org-babel-js-var-to-js): Replace newline characters
  with "\n" in strings.

Let's say I have a multi-line string stored in an example block.

I want to store my CSV in an example block.

#+NAME: my-csv-data
#+BEGIN_EXAMPLE
  ColA,ColB,ColC
  1,2,3
  4,5,6
#+END_EXAMPLE

I have a JavaScript function that accepts a string named 'csv' and passing in 'my-csv-data'.

#+BEGIN_SRC js :var csv=my-csv-data :results output
  console.log(csv);
#+END_SRC

When I expand the source block I end up with:

#+BEGIN_SRC js
var csv="ColA,ColB,ColC
  1,2,3
  4,5,6";
console.log(csv);
#+END_SRC

This will not execute correctly because JavaScript does not support newlines in strings.

What I want instead is:

#+BEGIN_SRC js
  var csv="ColA,ColB,ColC\n  1,2,3\n  4,5,6";
  console.log(csv);
#+END_SRC

TINYCHANGE
--8<---------------cut here---------------end--------------->8---


Regards,

-- 
Nicolas Goaziou

Re: Issue with multiline string variable for JavaScript source code blocks

[Peter Moresi]

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Excellent and thanks for the feedback. I'm glad I was able to give
something back to the community that has given me so much.

I've also had issues with JavaScript source code blocks truncating the
result when the value is a string with a comma. I'm still getting up to
speed with Emacs-lisp but when I figure out how to fix the issue I will
send the patch with proper comments.

Thanks,
Peter

On Friday, November 21, 2014, Nicolas Goaziou <mail@nicolasgoaziou.fr>
wrote:

> Hello,
>
> Peter Moresi <peter.moresi@gmail.com <javascript:;>> writes:
>
> > Sure, the patch is attached.​
>
> Applied. Thank you.
>
> However I had to fill your commit message, which was incomplete. For
> reference, here is what I used, from your initial report:
>
> --8<---------------cut here---------------start------------->8---
> ob-js: Fix passing multiline variables
>
> * lisp/ob-js.el (org-babel-js-var-to-js): Replace newline characters
>   with "\n" in strings.
>
> Let's say I have a multi-line string stored in an example block.
>
> I want to store my CSV in an example block.
>
> #+NAME: my-csv-data
> #+BEGIN_EXAMPLE
>   ColA,ColB,ColC
>   1,2,3
>   4,5,6
> #+END_EXAMPLE
>
> I have a JavaScript function that accepts a string named 'csv' and passing
> in 'my-csv-data'.
>
> #+BEGIN_SRC js :var csv=my-csv-data :results output
>   console.log(csv);
> #+END_SRC
>
> When I expand the source block I end up with:
>
> #+BEGIN_SRC js
> var csv="ColA,ColB,ColC
>   1,2,3
>   4,5,6";
> console.log(csv);
> #+END_SRC
>
> This will not execute correctly because JavaScript does not support
> newlines in strings.
>
> What I want instead is:
>
> #+BEGIN_SRC js
>   var csv="ColA,ColB,ColC\n  1,2,3\n  4,5,6";
>   console.log(csv);
> #+END_SRC
>
> TINYCHANGE
> --8<---------------cut here---------------end--------------->8---
>
>
> Regards,
>
> --
> Nicolas Goaziou
>

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