Re: [O] org-babel-execute:dot -- why doesn't this work?

[Matt Price]

On Thu, Sep 24, 2015 at 12:00 AM, Nick Dokos <address@hidden> wrote:

Matt Price <address@hidden> writes:

> I would, however, like to avoid the clumsy intermediate step and use something like this instead:
> #+name: graph-from-tables
> #+HEADER: :var nodes=students-table graph=students-graph horiz='t
> #+BEGIN_SRC emacs-lisp :file ~/example-diagram.png :colnames yes :exports results
>   (org-babel-execute:dot
>    (concat
>     "graph {\n"
>     (when horiz "rankdir=LR;\n")       ;up-down or left-right
>     (mapconcat
>      (lambda (x)
>        (format "%s [label=\"%s\" shape=%s style=\"filled\" fillcolor=\"%s\"]"
>                (car x)
>                (nth 1 x)
>                (if (string= "" (nth 2 x)) "box" (nth 2 x))
>                (if (string= "" (nth 3 x)) "none" (nth 3 x))
>                )) nodes "\n")
>     "\n"
>     (mapconcat
>     (lambda (x)
>       (format "%s -- %s;"
>               (car x) (nth 1 x) )) graph "\n")
>     "}\n") params)
> #+END_SRC
>

There are a couple of problems, one minor (the :colnames yes part
truncates the graph so you have only two edges), and one major: the
"params" argument is not defined.

When a dot source block is passed to org-babel-execute:dot, the params
argument I get [fn:1] is:

((:comments . #1="") (:shebang . #1#) (:cache . "no") (:padline . #1#)
 (:noweb . "no") (:tangle . "no") (:exports . "results")
 (:results . "file replace") (:session . "none") (:hlines . "no")
 (:file . "Images/foobar.png") (:result-type . value)
 (:result-params "file" "replace") (:rowname-names) (:colname-names))

So I tried passing it to org-babel-execute:dot and somewhat
to my surprise it worked [fn:2] - try evaluating the following in your
*scratch* buffer (make sure there is an Images subdir under the
current directory of that buffer):

--8<---------------cut here---------------start------------->8---

(org-babel-execute:dot
 "graph {
rankdir=LR;
a [label=\"Omar\" shape=ellipse style=\"filled\" fillcolor=\"green\"]
b [label=\"Hindia\" shape=ellipse style=\"filled\" fillcolor=\"orange\"]
c [label=\"Yuvrai\" shape=ellipse style=\"filled\" fillcolor=\"purple\"]
a -- b;
a -- c;
b -- c;
}
"
 '((:comments . #1="") (:shebang . #1#) (:cache . "no") (:padline . #1#)
 (:noweb . "no") (:tangle . "no") (:exports . "results")
 (:results . "file replace") (:session . "none") (:hlines . "no")
 (:file . "Images/foobar.png") (:result-type . value)
 (:result-params "file" "replace") (:rowname-names) (:colname-names)))
--8<---------------cut here---------------end--------------->8---

But I would hardly call this method less clumsy than your earlier
attempt.

Footnotes:

[fn:1]  I made a simple dot source block with your graph

#+BEGIN_SRC dot :file Images/foobar.png
graph {
rankdir=LR;
a [label="Omar" shape=ellipse style="filled" fillcolor="green"]
b [label="Hindia" shape=ellipse style="filled" fillcolor="orange"]
c [label="Yuvrai" shape=ellipse style="filled" fillcolor="purple"]
a -- b;
a -- c;
b -- c;
}
#+END_SRC

and instrumented org-babel-execute:dot under edebug - when I executed the code
block, the debugger kicked in when the function got called and I could
get the "params" argument.

[fn:2] I thought the #1 and #1# constructs (which I don't understand at
       all) would make it blow up.

--
Nick

Many thanks, Nick, and especially to the pointer to edebug (so obvious once you say it!).  With my original code, I stepped through the whole function and I can't quite understand why it's not working. The code block text is generated as expected, but somehow it's not getting written, or perhaps not executed by dot, as hoped.  Here is the debugging output:

(nodes (quote (("a" "Omar" "ellipse" "green") ("b" "Hindia" "ellipse" "orange") ("c" "Yuvrai" "ellipse" "purple"))))

(graph (quote (("a" "b") ("a" "c"))))

(horiz (quote t))

funcall-interactively: Buffer is read-only: #<buffer ob-dot.el> [4 times]

Result: ((:comments . #1="") (:shebang . #1#) (:cache . "no") (:padline . #1#) (:noweb . "no") (:tangle . "no") (:exports . "results") (:results . "file replace") (:var nodes ("a" "Omar" "ellipse" "green") ("b" "Hindia" "ellipse" "orange") ("c" "Yuvrai" "ellipse" "purple")) (:var graph ("a" "b") ("a" "c")) (:var horiz . t) (:colnames . "yes") (:file . "~/example-diagram.png") (:hlines . "no") (:session . "none") (:result-type . value) (:result-params "file" "replace") (:rowname-names) (:colname-names (nodes "*node*" "*label*" "*shape*" "*fillcolor*") (graph "From" "To")))

Result: (:result-params "file" "replace")

Result: ("file" "replace")

Stop

Result: ((:comments . #1="") (:shebang . #1#) (:cache . "no") (:padline . #1#) (:noweb . "no") (:tangle . "no") (:exports . "results") (:results . "file replace") (:var nodes ("a" "Omar" "ellipse" "green") ("b" "Hindia" "ellipse" "orange") ("c" "Yuvrai" "ellipse" "purple")) (:var graph ("a" "b") ("a" "c")) (:var horiz . t) (:colnames . "yes") (:file . "~/example-diagram.png") (:hlines . "no") (:session . "none") (:result-type . value) (:result-params "file" "replace") (:rowname-names) (:colname-names (nodes "*node*" "*label*" "*shape*" "*fillcolor*") (graph "From" "To")))
Stop

Result: (:file . "~/example-diagram.png")
Stop

Result: (:file . "~/example-diagram.png")
Stop

Result: "~/example-diagram.png"

Result: ((:comments . #1="") (:shebang . #1#) (:cache . "no") (:padline . #1#) (:noweb . "no") (:tangle . "no") (:exports . "results") (:results . "file replace") (:var nodes ("a" "Omar" "ellipse" "green") ("b" "Hindia" "ellipse" "orange") ("c" "Yuvrai" "ellipse" "purple")) (:var graph ("a" "b") ("a" "c")) (:var horiz . t) (:colnames . "yes") (:file . "~/example-diagram.png") (:hlines . "no") (:session . "none") (:result-type . value) (:result-params "file" "replace") (:rowname-names) (:colname-names (nodes "*node*" "*label*" "*shape*" "*fillcolor*") (graph "From" "To")))
Stop

Result: nil
Stop

Result: nil
Stop

Stop

Result: "~/example-diagram.png"

Result: "png"

Result: "-Tpng"

Result: "-Tpng"

Result: ((:comments . #1="") (:shebang . #1#) (:cache . "no") (:padline . #1#) (:noweb . "no") (:tangle . "no") (:exports . "results") (:results . "file replace") (:var nodes ("a" "Omar" "ellipse" "green") ("b" "Hindia" "ellipse" "orange") ("c" "Yuvrai" "ellipse" "purple")) (:var graph ("a" "b") ("a" "c")) (:var horiz . t) (:colnames . "yes") (:file . "~/example-diagram.png") (:hlines . "no") (:session . "none") (:result-type . value) (:result-params "file" "replace") (:rowname-names) (:colname-names (nodes "*node*" "*label*" "*shape*" "*fillcolor*") (graph "From" "To")))
Stop

Result: nil
Stop

Result: nil
Stop

Result: "dot"

Result: "/tmp/babel-2749DTL/dot-2749Nkt"

Result: "/tmp/babel-2749DTL/dot-2749Nkt"

Result: "graph {\nrankdir=LR;\na [label=\"Omar\" shape=ellipse style=\"filled\" fillcolor=\"green\"]\nb [label=\"Hindia\" shape=ellipse style=\"filled\" fillcolor=\"orange\"]\nc [label=\"Yuvrai\" shape=ellipse style=\"filled\" fillcolor=\"purple\"]\na -- b;\na -- c;}\n"
Stop

Result: ((:comments . #1="") (:shebang . #1#) (:cache . "no") (:padline . #1#) (:noweb . "no") (:tangle . "no") (:exports . "results") (:results . "file replace") (:var nodes ("a" "Omar" "ellipse" "green") ("b" "Hindia" "ellipse" "orange") ("c" "Yuvrai" "ellipse" "purple")) (:var graph ("a" "b") ("a" "c")) (:var horiz . t) (:colnames . "yes") (:file . "~/example-diagram.png") (:hlines . "no") (:session . "none") (:result-type . value) (:result-params "file" "replace") (:rowname-names) (:colname-names (nodes "*node*" "*label*" "*shape*" "*fillcolor*") (graph "From" "To")))
Stop

Result: "graph {\nrankdir=LR;\na [label=\"Omar\" shape=ellipse style=\"filled\" fillcolor=\"green\"]\nb [label=\"Hindia\" shape=ellipse style=\"filled\" fillcolor=\"orange\"]\nc [label=\"Yuvrai\" shape=ellipse style=\"filled\" fillcolor=\"purple\"]\na -- b;\na -- c;}\n"
Stop

Result: nil
Stop

Result: nil
Stop

Stop

Stop

Result: "dot"

Result: "/tmp/babel-2749DTL/dot-2749Nkt"

Result: "/tmp/babel-2749DTL/dot-2749Nkt"

Result: "-Tpng"

Stop

Result: "~/example-diagram.png"

Result: "/home/matt/example-diagram.png"
Stop

Result: "dot /tmp/babel-2749DTL/dot-2749Nkt -Tpng -o /home/matt/example-diagram.png"
Stop

Wrote /tmp/babel-2749DTL/ob-input-2749auz
Result: ""

Result: nil

Code block evaluation complete.
Mark set
 

-----

it looks about right until the very end; Manually running "dot /tmp/babel-2749DTL/dot-2749Nkt -Tpng -o /home/matt/example-diagram.png" from a shell works fine. However, the result of:

(org-babel-eval
     (concat cmd
         " " (org-babel-process-file-name in-file)
         " " cmdline
         " -o " (org-babel-process-file-name out-file)) "")

is "nil".  Any idea why that might be? 

Again, many thanks,

Matt