Process attachments in PDF

[opoudjis]

Follow-on from #709

Attachments are now included in Presentation XML. I describe how in metanorma/metanorma#353

The task for you is to do... something with these attachments in PDF. I don't know what or how, but @ronaldtse has said that this is expected by our clients. The PRs in metanorma-standoc and isodoc are staying draft until you have a resolution to this, but the attachments are currently treated in Presentation XML as links to assets in the attachments subfolder. The Semantic and Presentation XML retain Data URIs for the attachments, but Data URI generation for attachments is optional (though default behaviour.)

[opoudjis]

Archive 4.zip

The attached is an example of Presentation XML linking to an attachments folder.

[Intelligent2013]

From a.presentation.xml:

	<metanorma-extension>
		...
		<attachment name="spec_helper.rb">data:application/octet-stream;base64,cmVxdWlyZ...</attachment>
		
	</metanorma-extension>
	
	...
	<sections>
		<clause id="_cl" inline-header="false" obligation="normative" displayorder="2">
			<title depth="1">1<tab/>Cl</title>
			<p id="_ea5d9037-eb3f-8819-ce7c-2b595e4dd1c6">
				<link target="/Users/nickn/Documents/Arbeit/upwork/ribose/metanorma-iso/_a_attachments/spec_helper.rb">text</link>
			</p>
		</clause>
	</sections>

Tasks:

• the data from metanorma-extension/attachment should be included in PDF as attachments
  • if attachment/text() isn't empty, then decode file from base64 and attach it into PDF
  • if ``attachment/text()` is empty, then
    • determine the current XML file name (before .presentation.xml if presents), and
    • attach the file from the folder _{filename}_attachments
• the click on the link <link target="/Users/nickn/Documents/Arbeit/upwork/ribose/metanorma-iso/_a_attachments/spec_helper.rb">text</link> opens the attached file

[Intelligent2013]

If link/@target contains /_{filename}_attachments/ then it means that this link points to the PDF attachment file.

[Intelligent2013]

XSLT and mn2pdf (https://github.com/metanorma/mn2pdf/releases/tag/v1.84) updated to support the attachments in the PDF.

Note: on my machine this message is showing when I tried to open the attachments:

The preferences allow to open files, but the button Restore isn't enabled.

Example with spec_helper.rb: a.presentation.pdf

I've renamed the attachment to spec_helper.txt in the source Presentation XML and after that everything is working.
Example with spec_helper.txt :a.presentation.pdf

When I add the attachment manually by the Acrobat:

On the page https://helpx.adobe.com/acrobat/using/attachments-security-risks-reader-acrobat.html:

but I didn't change the attachment defaults.

Only way to change it - via Windows registry (found here https://community.adobe.com/t5/acrobat-discussions/adobe-cannot-open-the-file-attachment-because-your-pdf-file-attachment-settings-do-not-allow/td-p/10984499 and https://www.adobe.com/devnet-docs/acrobatetk/tools/AppSec/attachments.html)
.rb is present in the list tBuiltInPermList:

I've change to .rb:0:

and spec_helper.rb is opening now.