ePub Validation Error

sn12 · 03-07-2012, 10:47 AM

Hi there everyone,

I am confused by an error that has come up in ePubCheck.
I prepared my epub in InDesign and converted it in Calibre. I then ran the converted file through the IDPF epub validator online. It returned two errors, which were similar to one another.

1. ERROR. content.opf. Line 22, position 114. Value of attribute 'id' is invalid; must be an XML name without colons.

and

2. ERROR. content.opf. Line 64, position 60. Value of attribute 'idref' is invalid; must be an XML name without colons.

If anyone has any thoughts on why these occurred and how I can alter my epub to fix these errors, I would be very grateful. I have worked on epubs in the past and never encountered this error.

Thank you!

Toxaris · 03-07-2012, 12:48 PM

It sounds rather straightforward actually. There are some problems with your opf. What are lines 22 and 64?
This must be identifiers which can be used as a reference towards to files in the ePUB. In the spine there is usually a 'idref' with the same name. I don't know what ID uses for id names, but Sigil uses the filenames (which makes sense). I assume there are non valid characters in your id. Any spaces or other non-letter/digit characters?

Also, run the ePUB through FlightCrew. You might get other errors or at least better descriptions.

amyg · 03-07-2012, 05:34 PM

ID uses the file name also without file extension of course. I've never had a problem with the id or idref not validating. Maybe Calibre is messing things up. Since ID does epub conversion, I'm not sure what you need Calibre for. Why not output straight to epub from InDesign?

Toxaris · 03-08-2012, 01:51 AM

Well, the ePUB export of ID is not perfect and has flaws. As far as I know, the most people do the final touching up in Sigil.

Anyway, I think there are strange characters in the filename then.

sn12 · 03-08-2012, 05:51 AM

Thank you all for your helpful advice. This will be very useful in future in helping me understand problems I encounter. I ran the epub through calibre once more before making changes, and it validated this time. Not sure where the mysterious errors went! Thank you again for all the help.

amyg · 03-08-2012, 09:45 AM

Toxarix, with CS 5.5 it's actually pretty good, though not perfect. The html code is clean. I use export tagging and my own CSS style sheet so I have more control over the style naming. I need to put the guide section into the opf file and I use my own cover and title html pages that I create by hand so I pop those in. I tried Sigil but I didn't like it. It made unnecessary changes just opening and closing the epub. I have more control tweaking the files in a text editor or Dreamweaver.

But what I don't understand is how you would use Calibre in conjunction with InDesign. As far as I know, you can't tweak the epub in Calibre.

Toxaris · 03-08-2012, 10:50 AM

Quote:

Originally Posted by sn12

Thank you all for your helpful advice. This will be very useful in future in helping me understand problems I encounter. I ran the epub through calibre once more before making changes, and it validated this time. Not sure where the mysterious errors went! Thank you again for all the help.

Please, don't do ePUB to ePUB conversion in Calibre. You can break things and it really produces messy code.

Toxaris · 03-08-2012, 10:54 AM

Quote:

Originally Posted by amyg

Toxarix, with CS 5.5 it's actually pretty good, though not perfect. The html code is clean. I use export tagging and my own CSS style sheet so I have more control over the style naming. I need to put the guide section into the opf file and I use my own cover and title html pages that I create by hand so I pop those in. I tried Sigil but I didn't like it. It made unnecessary changes just opening and closing the epub. I have more control tweaking the files in a text editor or Dreamweaver.

But what I don't understand is how you would use Calibre in conjunction with InDesign. As far as I know, you can't tweak the epub in Calibre.

Version 5.5 is reasonable, but not good enough. A lot of things still produces problems.

Sigil does not make any unnecessary changes. It might rearrange the files in folders, but that does make it more consistent and is according to the ePUB specification. It also is more consistent in using styles, but that can be switched off. It will ensure structurally valid ePUB's. Also, the validation is unsurpassed. It is better than ePubCheck.
I very much doubt you have more control in Dreamweaver or a text editor, especially with the PCRE S&R. However, to each its own.

amyg · 03-08-2012, 11:44 AM

Text Wrangler and Dreamweaver both have regular expression search and replace. But as you said, to each his own. We all have our preferred workflows. I very rarely post about mine because of this. I just couldn't understand the need for Calibre in conjunction with InDesign. That was really the crux of my post.

03-07-2012, 10:47 AM	#1
sn12 Junior Member Posts: 2 Karma: 10 Join Date: Feb 2012 Device: None	ePub Validation Error Hi there everyone, I am confused by an error that has come up in ePubCheck. I prepared my epub in InDesign and converted it in Calibre. I then ran the converted file through the IDPF epub validator online. It returned two errors, which were similar to one another. 1. ERROR. content.opf. Line 22, position 114. Value of attribute 'id' is invalid; must be an XML name without colons. and 2. ERROR. content.opf. Line 64, position 60. Value of attribute 'idref' is invalid; must be an XML name without colons. If anyone has any thoughts on why these occurred and how I can alter my epub to fix these errors, I would be very grateful. I have worked on epubs in the past and never encountered this error. Thank you!

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
epub validation error	adetutuijose	ePub	12	01-14-2012 10:05 PM
Epub Validation Error	DTurner	ePub	6	09-12-2011 05:13 PM
Epub validation Error	fiona86	ePub	3	06-25-2011 12:57 AM
epub validation error	sassanik	Sigil	19	12-08-2010 05:46 AM
ePub Validation Error	mrbillb	ePub	6	09-28-2010 02:14 PM

03-07-2012, 12:48 PM	#2
Toxaris Wizard Posts: 4,520 Karma: 121692313 Join Date: Oct 2009 Location: Heemskerk, NL Device: PRS-T1, Kobo Touch, Kobo Aura	It sounds rather straightforward actually. There are some problems with your opf. What are lines 22 and 64? This must be identifiers which can be used as a reference towards to files in the ePUB. In the spine there is usually a 'idref' with the same name. I don't know what ID uses for id names, but Sigil uses the filenames (which makes sense). I assume there are non valid characters in your id. Any spaces or other non-letter/digit characters? Also, run the ePUB through FlightCrew. You might get other errors or at least better descriptions.

03-07-2012, 05:34 PM	#3
amyg Enthusiast Posts: 40 Karma: 56 Join Date: Sep 2011 Location: Los Angeles, CA Device: Nook simple touch, iPad	ID uses the file name also without file extension of course. I've never had a problem with the id or idref not validating. Maybe Calibre is messing things up. Since ID does epub conversion, I'm not sure what you need Calibre for. Why not output straight to epub from InDesign?

03-08-2012, 01:51 AM	#4
Toxaris Wizard Posts: 4,520 Karma: 121692313 Join Date: Oct 2009 Location: Heemskerk, NL Device: PRS-T1, Kobo Touch, Kobo Aura	Well, the ePUB export of ID is not perfect and has flaws. As far as I know, the most people do the final touching up in Sigil. Anyway, I think there are strange characters in the filename then.

03-08-2012, 05:51 AM	#5
sn12 Junior Member Posts: 2 Karma: 10 Join Date: Feb 2012 Device: None	Thank you all for your helpful advice. This will be very useful in future in helping me understand problems I encounter. I ran the epub through calibre once more before making changes, and it validated this time. Not sure where the mysterious errors went! Thank you again for all the help.

03-08-2012, 09:45 AM	#6
amyg Enthusiast Posts: 40 Karma: 56 Join Date: Sep 2011 Location: Los Angeles, CA Device: Nook simple touch, iPad	Toxarix, with CS 5.5 it's actually pretty good, though not perfect. The html code is clean. I use export tagging and my own CSS style sheet so I have more control over the style naming. I need to put the guide section into the opf file and I use my own cover and title html pages that I create by hand so I pop those in. I tried Sigil but I didn't like it. It made unnecessary changes just opening and closing the epub. I have more control tweaking the files in a text editor or Dreamweaver. But what I don't understand is how you would use Calibre in conjunction with InDesign. As far as I know, you can't tweak the epub in Calibre.

03-08-2012, 11:44 AM	#9
amyg Enthusiast Posts: 40 Karma: 56 Join Date: Sep 2011 Location: Los Angeles, CA Device: Nook simple touch, iPad	Text Wrangler and Dreamweaver both have regular expression search and replace. But as you said, to each his own. We all have our preferred workflows. I very rarely post about mine because of this. I just couldn't understand the need for Calibre in conjunction with InDesign. That was really the crux of my post.

Advert

Advert