Question about dc:identifier

[bookman156]

I have a number of epub 3 files to prepare that are structurally similar. I was thinking of getting one file ready in Sigil with all the fonts and CSS etc and then just saving under another name and swapping the cover and content for each new epub.

But this would mean the dc:identifier number would be the same. I guess this is generated randomly every time Sigil opens. What purpose does the dc:identifier number serve? And could I just change it to something else manually in .opf file for each new epub? Is it necessary to have it at all?

[DNSB]

Originally Posted by bookman156

I have a number of epub 3 files to prepare that are structurally similar. I was thinking of getting one file ready in Sigil with all the fonts and CSS etc and then just saving under another name and swapping the cover and content for each new epub.

But this would mean the dc:identifier number would be the same. I guess this is generated randomly every time Sigil opens. What purpose does the dc:identifier number serve? And could I just change it to something else manually in .opf file for each new epub? Is it necessary to have it at all?

The dc:identifier is a required element and must be unique. See dc:identifer on the EPUB 3.3 candidate draft though that wording hasn't changed much in a decade.

[KevinH]

The existing dc identifier should be unique. The primary one is used in font deobfuscation/obfuscation. It can be used in the ncx as well and must match the opf one if an ncx exists.

A random uuid primary dc:identifier can be generated for new empty epubs.

But using the template epub plugin would be even easier as it was designed to handle that.

https://www.mobileread.com/forums/sh...d.php?t=341735

[bookman156]

Ah, the template plugin looks interesting.

But to check, I could just open up Sigil, copy a freshly generated identifier, and then paste that into the epub I created by save-as, and I would be achieving the same, yes?

[Tex2002ans]

Originally Posted by bookman156

I have a number of epub 3 files to prepare that are structurally similar. I was thinking of getting one file ready in Sigil with all the fonts and CSS etc and then just saving under another name and swapping the cover and content for each new epub.

You can create a basic "template" folder with your common:

• HTML files
  
  • Title page
    
  • Copyright page
    
  • Front/Backmatter
    
• CSS
• Fonts
• Images
  
  • Logos
    
  • Temporary covers
    

Then when you open an EPUB, you can "Import" those files.

Some of these methods were discussed in:

• 2018: "UUID basics & template"

Doitsu then created an "EPUBTemplate" plugin to handle just this case.

Edit: Ahh, yes. KevinH's "Template" plugins work even better! I think he came up with that one after the discussion in those UUID threads!

Originally Posted by bookman156

But this would mean the dc:identifier number would be the same. I guess this is generated randomly every time Sigil opens. What purpose does the dc:identifier number serve?

It is used in some devices for highlights/notes, syncing books, checking to see if file/book is new, etc.

Plus a few other technical EPUB things. (See topic below.)

Originally Posted by bookman156

And could I just change it to something else manually in .opf file for each new epub?

Yes, it is possible.

See the discussion in:

• 2019: "@DiapDealer ISBN vs UUID"

We went through all the in-depth details.

And I swear, somewhere along the line, someone made a plugin to generate a new random UUID without needing to create a new EPUB... but maybe I'm imagining that.

I always just started from a new EPUB + imported all needed "template" files in... or in the very rare case, I manually tweaked the UUIDs (using the instructions I wrote in this post).

[KevinH]

There are websites that provide uuid generators that might be easier to copy and paste from. Also python's uuid module has a built in support for generating them as well if you want to automate it in a script. The Template plugin would be easiest probably and does support loading exactly what you want with base xhtml, base css, etc. all in one go.

Originally Posted by bookman156

Ah, the template plugin looks interesting.

But to check, I could just open up Sigil, copy a freshly generated identifier, and then paste that into the epub I created by save-as, and I would be achieving the same, yes?

[CubGeek]

Originally Posted by KevinH

The existing dc identifier should be unique. The primary one is used in font deobfuscation/obfuscation. It can be used in the ncx as well and must match the opf one if an ncx exists.

A random uuid primary dc:identifier can be generated for new empty epubs.

But using the template epub plugin would be even easier as it was designed to handle that.

https://www.mobileread.com/forums/sh...d.php?t=341735

Thanks for this link!

Question about the instructions: They say to open the Sigil Plugin Preferences directory and place the "template3" directory there. I've done so (sigil-ebook\plugin_prefs\template3) and placed my template files into it using the FolderOut plugin. When I run the Template3 plugin now, however, I get "Status Failed: Template folder is not a directory or does not exist" error. I've tried case-sensitive (template3→Template3) and that doesn't work either. What am I doing wrong?


EDIT: ahhh... it needs to be in the sigil-ebook directory, not in the plugin_prefs directory. Seems the wording in the instructions threw me. Sorry about that!

[KevinH]

Yes where the Sigil Open Preference Folder points. There is a button inside Sigil Preferences that should take you there. Its location differs depending on platform and even build options on Linux.