Display date of file in library

[lalala987]

dear all

i use to sort my library by the column "date". it seems as if that's the date when the metadata of the book was last changed. that allows me to display the newest added book on the top/bottom of the grid.

For some reason that data hast changed. all my books do have the same date now! I have checked the files on my harddrive, the file date is correct, displaying the date the file was created. but that's not the case in calibre's library anymore!

Question: is there a way to order the books in the library by the date the file was created/edited on the harddrive?

regards

[theducks]

Originally Posted by lalala987

dear all

i use to sort my library by the column "date". it seems as if that's the date when the metadata of the book was last changed. that allows me to display the newest added book on the top/bottom of the grid.

For some reason that data hast changed. all my books do have the same date now! I have checked the files on my harddrive, the file date is correct, displaying the date the file was created. but that's not the case in calibre's library anymore!

Question: is there a way to order the books in the library by the date the file was created/edited on the harddrive?

regards

last_modified is the Timestamp of the Metadata change, not File

It can be triggered by anything that affects anything that shows in the Tag Browser (and a few others). (Not reliable for real changes)

Date is the date the RECORD was created (if you don't mess with that)

Published, well, that should be obvious

There is no database of the File date. You can hover over the format in the Metadata edit window and see the formats timestamp

[lalala987]

In the metadata dialoge there is a field named "date" which seems to contain the file date. did i understand you correctly that it is not possible to add a custom column with the file date?

[BetterRed]

Originally Posted by lalala987

In the metadata dialoge there is a field named "date" which seems to contain the file date. did i understand you correctly that it is not possible to add a custom column with the file date?

@lalala987 - long story short - calibre's Date and Modified columns have nothing to do with the file system's Date Created and Date Modified properties, the fact that they are similar when you first add a book is coincidental.

There is no feasible way show the file system dates within calibre itself (except via mouse hovering in a secondary window). A 'book' folder usually has several files: a cover.jpg, the metadata.opf file and one or more format files; all of which can have different values in their Date Created and Date Modified file system properties. So then the question becomes for which one of those should the file system dates be shown as columns for a given book...

The bottom line is - if you want to see the file system dates for a book press 'O' and examine what the file system manager reports them as being.

BR

[chaley]

If by "date of file" you mean the date of the book file(s) in the library then you can see them using a custom column "built from other columns". The template is

program: formats_modtimes('yyyy-MM-dd')

You can change the format of the displayed date to whatever you want. For example

program: formats_modtimes('yyyy-MM-dd hh:mm:ss')

shows the time using a 24-hour clock, resulting in a column that contains

MOBI:2013-10-25 09:06:35,EPUB:2013-10-12 18:25:52,PRC:2012-02-12 10:02:28

if the book has all of .mobi, .epub, and .prc formats.

Be aware that this kind of column can slow down calibre's GUI because the gui must look up the modtime of every book format. Experience indicates that this usually isn't a problem with under 1000 books. YMMV.

[BetterRed]

@chaley - were the formats_modtimes/paths/sizes functions recently added, I can recall other posts asking for some way to get the sizes and file system dates.

Originally Posted by chaley

Be aware that this kind of column can slow down calibre's GUI because the gui must look up the modtime of every book format.

If I only display the custom column (s) in the Book Information panel (keyboard 'I') does that mean the file system look ups are only done if I press 'I'.

BR

[chaley]

Originally Posted by BetterRed

@chaley - were the formats_modtimes/paths/sizes functions recently added, I can recall other posts asking for some way to get the sizes and file system dates.

Nope. These have been there for a long time, since 30/June/2011 if I read the change logs correctly.

If I only display the custom column (s) in the Book Information panel (keyboard 'I') does that mean the file system look ups are only done if I press 'I'.

BR

That is hard for me to answer definitively because the caching system has changed so much with the new DB. In the old DB, evaluating any composite caused all composites to be evaluated. However, reading the new DB code it appears a given composite is evaluated on demand, which means that you pay the penalty when you see the value. Furthermore, the value is cached so that you pay the penalty only once per full spreadsheet repaint. Note though that "seeing the value" also happens when sorting by that composite or if the composite is used as a field in another composite.

[BetterRed]

@chaley - thanks, yes, the new backend did speed up composite columns, I was able to reinstate one that I had previously removed because it was having an adverse effect on performance - so far so good.

I think I know why I missed the formats_xxx() functions, would have searched the manual for 'file' within 3 words of 'date' and 'size'.

The three formats_xxx functions work fine in Book Information as I envisaged. Would be good if one could optionally specify a format eg formats_size('EPUB'), formats_modtimes('MM/dd/yyyy', 'AZW3')

Discovery : you can sort on a column with the Sort By feature even though the column is not shown in the book list.

BTW : the PDF version of the manual has a 'misprint', see attachment, shows up in 4 viewers, Firefox, Chrome, XChange and Foxit. I think its been there for a while.

BR

[enriquep]

Some time ago I wanted to create a column that sorts books by date and time added (or modified) - and I managed to do it (... with a lot of help from others!!). I use it to keep track of changes, new additions, etc.

I know that this is not exactly what you are looking for, but having a look at that thread might be of some help: https://www.mobileread.com/forums/sho...d.php?t=238284

[BetterRed]

Originally Posted by enriquep

Some time ago I wanted to create a column that sorts books by date and time added (or modified) - and I managed to do it (... with a lot of help from others!!). I use it to keep track of changes, new additions, etc.

I know that this is not exactly what you are looking for, but having a look at that thread might be of some help: https://www.mobileread.com/forums/sho...d.php?t=238284

@enriquep - That link is this thread, I suspect you really meant this thread https://www.mobileread.com/forums/sho...d.php?t=154780

BR

[chaley]

Sorry, got busy and forgot to reply to this.

Originally Posted by BetterRed

@chaley - thanks, yes, the new backend did speed up composite columns, I was able to reinstate one that I had previously removed because it was having an adverse effect on performance - so far so good.

Good to hear.

The three formats_xxx functions work fine in Book Information as I envisaged. Would be good if one could optionally specify a format eg formats_size('EPUB'), formats_modtimes('MM/dd/yyyy', 'AZW3')

You can do this by composing two functions. "select" and the formats_ function you want to use. Example:

program: select(formats_modtimes('yyyy-MM-dd'), 'EPUB')

returns the date the EPUB was modified, or the empty string if there isn't an EPUB. Note that the key in "select" is case sensitive.

BTW : the PDF version of the manual has a 'misprint', see attachment, shows up in 4 viewers, Firefox, Chrome, XChange and Foxit. I think its been there for a while.

BR

Oh well. To paraphrase Kovid when he replies to bug reports involving PDF, "PDF has various limitations".

[enriquep]

Originally Posted by BetterRed

@enriquep - That link is this thread, I suspect you really meant this thread https://www.mobileread.com/forums/sho...d.php?t=154780

BR

BetterRed, You are absolutely right