Listing missing local files (improved warning)

[gleicher]

Is there a way to get a list of what local files are missing?

I am using marp cli to create PDFs. (this is a great workflow for my class lectures)

The terse error message is usually good. But sometimes, being told "[ WARN ] Some of the local files are missing and will be ignored. Make sure the file paths are correct." isn't enough - I'd like to know which local files (what lines in the markdown file).
(skimming over a 100 page lecture to find the missing image can be tricky)

Is there a way to get more verbose warning messages from the CLI?

Thank you,

Mike

[yhatt]

Marp CLI does not have an ability to show missing files, but you can do the same thing easily by using the browser with HTML export.

Export HTML into next to the Markdown file and open it in the browser that has enabled Developer Tools (F12). In the "Network" tab, missing resources while loading HTML will highlight.

[gleicher]

Thanks!
That's a good tip.
Unfortunately, what it tells me is that there isn't a missing file. (well, the browser can't find my fonts - which the PDF version is clearly getting right). This makes it myseterious why the pdf generation tells me there is a missing file. The resulting PDF looks good...

Maybe someday I will try to add a "verbose warnings" option that shows this (I am such a big fan of Marp that I'd like to find a way to contribute. Except that right now, I am so busy using it to prepare my class...)

[yhatt]

Marp CLI will convert HTML generated from Markdown to PDF so the above solution should be simulating to fetch local resources in the process of PDF conversion. However, sometimes may not reproduce exactly due to the difference of Chrome profiles (the profile for browsing web and the exclusive profile for Marp conversion). For example, that difference would be big if your organization was forcing specific configurations, extensions, or policies to Chrome. (chrome://policy to see the current policy) In addition, some of policies may have negative effects to Marp conversions.

--verbose option would become a good contribution to Marp CLI. We are always welcome to contribute :)

[Helle1]

I am having a similar problem.
My --html option works fine (no missing files in the browser) and when I use --pdf it says I am missing a file.

specifically, it is about a css file. I try to @import a sub-css file in my theme file.

/* @theme my-theme */

@import 'default'
@import '/themes/utils/sub-file.css'

...

my shell promt is:

$ npx marp slides/slideTemplate.md --theme themes/my-theme.css --allow-local-files --html

[  INFO ] Converting 1 markdown...
[  INFO ] slides/slideTemplate.md => slides/slideTemplate.html

$ npx marp slides/slideTemplate.md --theme themes/my-theme.css --allow-local-files --html --pdf

[  INFO ] Converting 1 markdown...
[  WARN ] Insecure local file accessing is enabled for conversion from slides/slideTemplate.md.
[  WARN ] The local file is missing and will be ignored. Make sure the file path is correct.
[  INFO ] slides/slideTemplate.md => slides/slideTemplate.pdf

The substyle is missing in the pdf, but working in html version.

What did I get wrong with the include?

[yhatt]

Marp team does not recommend importing external resources in CSS due to many troubles.

While the process of PDF conversion, Marp CLI will generate an intermediate HTML file to OS-specific temp directory (if allowed using local files). When generating, we instruct the correct base directory to HTML by using <base> tag. Resources in Markdown (e.g. images) respect this setting. However, the browser do not respect it for external resources specified in CSS.
https://stackoverflow.com/questions/2161377/is-the-html-base-tag-also-honored-by-scripting-and-css

If used relative path in style, the path always resolve from the directory that the HTML file is located. e.g. /var/tmp or C:\Users\%USER%\AppData\Local\Temp for PDF conversion.

Using absolute path, such as https://xxx.yyy/zzz (there is an absolute path determined by URI), might be temporarily resolved, but the created theme may become incompatible with other Marp tools because using @import for external CSS files will bypass Marpit's CSS scoping.
marp-team/marpit#363 (comment)

Thus, the most stable solution is stop using @import for external CSS files. If you want to keep using relative path in @import, you also can try to inline external CSS contents with PostCSS and postcss-import or postcss-url before using in Marp. (Actually Marp Core is inlining url() on build time powered by postcss-url)

[Helle1]

Wow thanks for the quick and deep and complete answer. Thank you very much.
I was already also thinking about the postcss import approach. I will go for it.

[Helle1]

My solution now is to preprocess the css with less in npm.
You need to add ignore the @import (inline) "default"; directive with the (inline) word, and change the theme.css to theme.less as well as the sub-file.

my themes.less-file looks like this now:

 /* @theme my-theme */

@import (inline) 'default'
@import 'utils/sub-file'

and my cli call:

$ npx less themes/my-theme.less > themes/my-theme.css && npx marp slides/slideTemplate.md --theme themes/my-theme.css --allow-local-files --html --pdf

that works fine (you need to install less: npm i less --save-dev)