UUID creation?

Turtle91 · 05-23-2013, 08:34 AM

I use a template when creating new ePubs - all the standard Cover/Title/CSS/OPF files already in a "default.epub" file which then gets Saved-As the new title. Everything has been going great until I realized that I've been forgetting to change the UUID in the OPF!

Code:

<dc:identifier id="BookId" opf:scheme="UUID">
urn:uuid:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx</dc:identifier>

Is there some magic formula or scheme that should be followed when creating a new UUID?

And, more importantly, does Sigil have a function for doing that? If not, can it be added??

DiapDealer · 05-23-2013, 08:55 AM

Quote:

Originally Posted by Turtle91

Is there some magic formula or scheme that should be followed when creating a new UUID?

Depends on what kind of Unique ID you want to create. Random urn? ISBN? Your own custom scheme?

Quote:

And, more importantly, does Sigil have a function for doing that?

No (except when opening a new blank epub). The only way to get Sigil to generate a new urn:uuid (that I know of) is to completely remove the <dc:identifier></dc:identifier> entry from the opf file. Unfortunately, this also has the rather unfortunate side effect of Sigil believing your opf is broken--so it creates a new opf from scratch. Something you definitely don't want happening.

PeterT · 05-23-2013, 09:03 AM

http://www.famkruithof.net/uuid/uuidgen might be of use.

Turtle91 · 05-23-2013, 09:21 AM

@PeterT: Thanks! At least I now have 500 UUID's to hold me over!

@Diap: I was thinking a random ID... but the idea is to keep them unique. The link Peter posted uses a time stamp combined with a code based on his network gear?? I would think something along these lines would be very simple to incorporate into Sigil - a button in the metadata editor or something - especially since it already has the functionality to generate the code - we just need to tell it to do it.

roger64 · 05-23-2013, 09:51 AM

Hi

There is a Linux standard command line tool called, what else?, uuidgen.

Jellby · 05-23-2013, 11:51 AM

I simply use Jellby:YYYYMMDDx

where YYYYMMDD is the date of creation, and x is a letter I add if I create more than one a single day.

Turtle91 · 05-23-2013, 01:13 PM

Quote:

Originally Posted by Jellby

I simply use Jellby:YYYYMMDDx

where YYYYMMDD is the date of creation, and x is a letter I add if I create more than one a single day.

lol...I didn't realize it could be that simple. I thought it had to follow that 8-4-4-4-12 format.

Although, aren't you worried there might be another Jellby out there doing the same thing - thus making the ID non-unique??!!??

st_albert · 05-23-2013, 01:13 PM

Out of curiosity, what would be the consequences if there were two separate epubs with the same identical UUID? Under what circumstances would the collision be detected?

Turtle91 · 05-23-2013, 01:20 PM

I found it when I was using the firefox plugin ePubReader to read my books. When I added the second book (and the third, fourth, fifth etc.) with a UUID of a book that was already in the catalog, it would delete the first book and replace it with the new one...thinking it was an updated version of the same book.

I haven't had that issue with the limited number of other readers I've tried, but it seems like it could cause a problem.

mrmikel · 05-24-2013, 06:56 AM

Quote:

Originally Posted by Turtle91

I found it when I was using the firefox plugin ePubReader to read my books. When I added the second book (and the third, fourth, fifth etc.) with a UUID of a book that was already in the catalog, it would delete the first book and replace it with the new one...thinking it was an updated version of the same book.

I haven't had that issue with the limited number of other readers I've tried, but it seems like it could cause a problem.

It ought to be reported as a bug, so that the developer can throw a dialog box in there asking if it is the same and the other should be deleted. It may only be deleted from its own internal index, but still....

Turtle91 · 05-24-2013, 10:01 AM

Quote:

Originally Posted by mrmikel

It ought to be reported as a bug, so that the developer can throw a dialog box in there asking if it is the same and the other should be deleted. It may only be deleted from its own internal index, but still....

I did email the dev about the quirky behavior...that's how I found out what the problem was. Apparently he thought that wasn't a bug, but a feature!

lol

DrChiper · 05-24-2013, 12:43 PM

ahh, the undocumented features again ..., memories, memories ...

Hitch · 05-24-2013, 10:34 PM

Quote:

Originally Posted by st_albert

Out of curiosity, what would be the consequences if there were two separate epubs with the same identical UUID? Under what circumstances would the collision be detected?

The earth would stop rotating on its axis, and we'd all spin off. I hate when that happens.

Hitch

abeonis · 05-31-2013, 07:14 AM

Quote:

Originally Posted by DiapDealer

Depends on what kind of Unique ID you want to create.
No (except when opening a new blank epub). The only way to get Sigil to generate a new urn:uuid (that I know of) is to completely remove the <dc:identifier></dc:identifier> entry from the opf file. Unfortunately, this also has the rather unfortunate side effect of Sigil believing your opf is broken--so it creates a new opf from scratch. Something you definitely don't want happening.

Actually, you gave the solution:

1. Create a new blank epub, copy the uuid
2. Paste it into your original OPF
3. Edit the original NCX with your new uuid
4. Delete the new blank epub to avoid that ...

Quote:

Originally Posted by Hitch

The earth would stop rotating on its axis, and we'd all spin off.

Should work.

Turtle91 · 05-31-2013, 12:31 PM

Quote:

Originally Posted by abeonis

Actually, you gave the solution:

1. Create a new blank epub, copy the uuid
2. Paste it into your original OPF
3. Edit the original NCX with your new uuid
4. Delete the new blank epub to avoid that ...

Should work.

Yes, that would certainly work. Since Sigil has the ability to generate a new UUID it would be really nice to have a button, or switch to activate that functionality...opening/copying/pasting/closing is sooooo '80's

Quote:

Originally Posted by Hitch

The earth would stop rotating on its axis, and we'd all spin off.

Ah Hitch...making me dust off my Rocket Science Degree....it isn't the spinning of the Earth that keeps us attached, it is the force of gravity. As we all know F=Gm2m1/r^2 where G is the gravitational constant and m1/m2 are the masses of the two bodies and r is the distance between them. At no time is the angular speed of the Earth part of the equation. How do you think the astronauts could walk on the asteroid to plant the bomb in Armageddon?? Now if the Earth did stop spinning it would actually make it HARDER (in most non-polar insertions) to get into orbit, because we could not rely on that same angular speed (greatest at the equator) to contribute to the critical speed - the speed needed to achieve orbital velocity.....

Hello

Hello

Hitch, there is no sleeping during my lectures!!!

05-23-2013, 08:34 AM	#1
Turtle91 A Hairy Wizard Posts: 3,394 Karma: 20212733 Join Date: Dec 2012 Location: Charleston, SC today Device: iPhone 15/11/X/6/iPad 1,2,Air & Air Pro/Surface Pro/Kindle PW & Fire	UUID creation? I use a template when creating new ePubs - all the standard Cover/Title/CSS/OPF files already in a "default.epub" file which then gets Saved-As the new title. Everything has been going great until I realized that I've been forgetting to change the UUID in the OPF! Code: <dc:identifier id="BookId" opf:scheme="UUID"> urn:uuid:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx</dc:identifier> Is there some magic formula or scheme that should be followed when creating a new UUID? And, more importantly, does Sigil have a function for doing that? If not, can it be added??

05-23-2013, 09:51 AM	#5
roger64 Wizard Posts: 2,625 Karma: 3120635 Join Date: Jan 2009 Device: Kindle PW3 (wifi)	Hi There is a Linux standard command line tool called, what else?, uuidgen. Attached Thumbnails Last edited by roger64; 05-23-2013 at 09:54 AM.

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05-23-2013, 09:03 AM	#3
PeterT Grand Sorcerer Posts: 13,688 Karma: 79983758 Join Date: Nov 2007 Location: Toronto Device: Libra H2O, Libra Colour	http://www.famkruithof.net/uuid/uuidgen might be of use.

05-23-2013, 09:21 AM	#4
Turtle91 A Hairy Wizard Posts: 3,394 Karma: 20212733 Join Date: Dec 2012 Location: Charleston, SC today Device: iPhone 15/11/X/6/iPad 1,2,Air & Air Pro/Surface Pro/Kindle PW & Fire	@PeterT: Thanks! At least I now have 500 UUID's to hold me over! @Diap: I was thinking a random ID... but the idea is to keep them unique. The link Peter posted uses a time stamp combined with a code based on his network gear?? I would think something along these lines would be very simple to incorporate into Sigil - a button in the metadata editor or something - especially since it already has the functionality to generate the code - we just need to tell it to do it.

05-23-2013, 11:51 AM	#6
Jellby frumious Bandersnatch Posts: 7,570 Karma: 20150435 Join Date: Jan 2008 Location: Spaniard in Sweden Device: Cybook Orizon, Kobo Aura	I simply use Jellby:YYYYMMDDx where YYYYMMDD is the date of creation, and x is a letter I add if I create more than one a single day.

05-23-2013, 01:13 PM	#8
st_albert Guru Posts: 698 Karma: 150000 Join Date: Feb 2010 Device: none	Out of curiosity, what would be the consequences if there were two separate epubs with the same identical UUID? Under what circumstances would the collision be detected?

05-23-2013, 01:20 PM	#9
Turtle91 A Hairy Wizard Posts: 3,394 Karma: 20212733 Join Date: Dec 2012 Location: Charleston, SC today Device: iPhone 15/11/X/6/iPad 1,2,Air & Air Pro/Surface Pro/Kindle PW & Fire	I found it when I was using the firefox plugin ePubReader to read my books. When I added the second book (and the third, fourth, fifth etc.) with a UUID of a book that was already in the catalog, it would delete the first book and replace it with the new one...thinking it was an updated version of the same book. I haven't had that issue with the limited number of other readers I've tried, but it seems like it could cause a problem.

05-24-2013, 12:43 PM	#12
DrChiper Bookish Posts: 1,049 Karma: 2006208 Join Date: Jun 2011 Device: PC, t1, t2, t3, Clara BW, Clara HD, Libra 2, Libra Color, Nxtpaper 11	ahh, the undocumented features again ..., memories, memories ...