Thank you for the suggestion Hraban.

The source comes from Markdown, which is converted to XML, then typeset using ConTeXt. There's no Markdown-specific mechanism to relate images to a particular external figure definition, unfortunately. All images use the same syntax and are treated the same way. The only part that differs is the file name extension (and header within the file).

One possibility would be something like:

\setupexternalfigure[ width=1em, height=1em, order={svg,pdf,png,jpg}, location={local,default,global}, ] \defineexternalfigure[png][ width=\textwidth, height=\textheight, ] \unprotect \let\old_externalfigure=\externalfigure \tolerant\def\externalfigure[#1]#,[#2]#,[#3]{% \doifelseinstring{.png}{#1}{% \old_externalfigure[#1][png][#2]% }{% \doifelsefileexists{#1.png}{% \old_externalfigure[#1.png][png][#2]% }{% \old_externalfigure[#1][#2][#3]% }% }% }\protect

See: https://tex.stackexchange.com/a/650221/2148

I was wondering if there was a simpler or a solution that's more the ConTeXt-way?

Thanks again!

Thanks, Rik.

Not using Pandoc. I was using Pandoc up until 2020:

https://dave.autonoma.ca/blog/2019/05/22/typesetting-markdown-part-1/

I've since authored KeenWrite https://github.com/DaveJarvis/keenwrite, which uses flexmark-java https://github.com/vsch/flexmark-java to generate XHTML documents from Markdown. The only additions I've made to the library is to add support for Pandoc's annotation syntax (:::).

That said, I'm also a firm believer in not duplicating information. The information (file name extension) is already available in the documents, so adding a classification on top of the extension feels redundant.

Thanks for the suggestion!

On Tue, Jul 12, 2022 at 12:18 PM Rik Kabel via ntg-context < ntg-context@ntg.nl> wrote:

On 2022-07-12 14:11, Thangalin via ntg-context wrote:

Thank you for the suggestion Hraban.

The source comes from Markdown, which is converted to XML, then typeset using ConTeXt. There's no Markdown-specific mechanism to relate images to a particular external figure definition, unfortunately. All images use the same syntax and are treated the same way. The only part that differs is the file name extension (and header within the file).

One possibility would be something like:

\setupexternalfigure[ width=1em, height=1em, order={svg,pdf,png,jpg}, location={local,default,global}, ] \defineexternalfigure[png][ width=\textwidth, height=\textheight, ] \unprotect \let\old_externalfigure=\externalfigure \tolerant\def\externalfigure[#1]#,[#2]#,[#3]{% \doifelseinstring{.png}{#1}{% \old_externalfigure[#1][png][#2]% }{% \doifelsefileexists{#1.png}{% \old_externalfigure[#1.png][png][#2]% }{% \old_externalfigure[#1][#2][#3]% }% }% }\protect

See: https://tex.stackexchange.com/a/650221/2148

I was wondering if there was a simpler or a solution that's more the ConTeXt-way?

Thanks again!

Assuming that Pandoc markdown is being used, you should be able to set class attributes on each image. You can then associate external figure definitions with specific classes, and process each individually. (Pandoc user guide, link_attributes https://pandoc.org/MANUAL%202.html#extension-link_attributes)

-- Rik

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Thank you, Wolfgang.

That looks promising.

SVG files are converted using MetaPost. I thought the following would work:

svg=>{\externalfigure[#1][svg][conversion=mp]}

Is there anything else that needs to happen to ensure SVG files are piped through MetaPost?

Thanks again!

\setupexternalfigures [location={local,global,default}]

\defineexternalfigure [jpg] [width=4cm] \defineexternalfigure [png] [width=8cm]

\starttexdefinition includegraphics #1

\splitfilename{#1}

\processaction
    [\splitofftype]
    [    jpg=>{\externalfigure[#1][jpg]},
         png=>{\externalfigure[#1][png]},
     default=>{\externalfigure[#1]},
     unknown=>{\externalfigure[#1]}]

\stoptexdefinition

\starttext

\includegraphics{hacker.jpg}

\includegraphics{mill.png}

\includegraphics{cow.pdf}

\stoptext

Got it working. Complete solution:

\setupexternalfigures[ location={local,global,default}, width=\textwidth ]\defineexternalfigure[svg][width=1cm]\defineexternalfigure[jpg][width=2cm]\defineexternalfigure[png][width=4cm] % Won't be applied because there's no process action.% Default (\textwidth) is used, as defined above.\defineexternalfigure[pdf][width=6cm] \starttexdefinition includegraphics #1 \splitfilename{#1}

\processaction[\splitofftype][ jpg=>{\externalfigure[#1][jpg]}, png=>{\externalfigure[#1][png]}, svg=>{\externalfigure[#1][svg][conversion=mp]}, default=>{\externalfigure[#1]}, unknown=>{\externalfigure[#1]} ]\stoptexdefinition \starttext \includegraphics{kitten.jpg} \includegraphics{mill.png} \includegraphics{cow.pdf} \includegraphics{tiger.svg}\stoptext

Image files attached. Thanks again!

Thangalin via ntg-context ntg-context@ntg.nl writes:

The source comes from Markdown, which is converted to XML, then typeset using ConTeXt. There's no Markdown-specific mechanism to relate images to a particular external figure definition, unfortunately. All images use the same syntax and are treated the same way. The only part that differs is the file name extension (and header within the file).

The below is likely overkill and a good bit of work to setup, but it is also very flexible. Maybe it suits your needs.

The Markdown-to-XML conversion can be tuned to include all the relevant information. E.g., you could use pandoc with a custom writer to produce the XML format of your choice. The link below is an example XML writer that can be tuned as needed. https://gist.github.com/tarleb/634b409be0af62ca210cc9e96d41ca8c

With that setup, one can modify the `Image` function to produce the output you need. E.g., match on the file name extension use the library function `pandoc.path.split_extension` and then change the element type depending on the extension.

This way you'd have all the important information in your XML. More info: https://pandoc.org/custom-writers and https://pandoc.org/lua-filters.

Of course, you could also use pandoc to go directly to ConTeXt; that is currently my preferred way of producing PDF from Markdown.

Cheers, Albert