Custom Column question - Date field was last modified

[Comfy.n]

Hi all,

I have a Yes/No custom column named #fav, that I use in conjunction with Action Chains plugin (Single Field Edit) to set a star emblem in Cover Grid by pressing F, dedicated to store my favourite titles.

Today I wanted to see the date some title was added to Favourites, as if it were possible to sort those "bookmarks" the same way web browsers like Waterfox Classic do... then I noticed I couldn't. lol

So I think I need to create a new custom column of the type "built from other columns", that will look for the value stored in #fav and set the date that value was changed, is that correct?

I looked into the template language section of the Calibre docs, but couldn't figure out how to create that custom column. In fact, the only custom column I have of the "built from other columns" type is one that uses the {:'approximate_formats()'} function, which was easy to do as all it needed was a simple copy/paste from the manual.

BTW I learned the other day that the custom columns feature was contributed to Calibre by @chaley, thank you so much Mr. Haley.

[capink]

I am not sure I understand what you want to do? From what I gather you want to store the date at which the #fav column is changed for sorting purposes?

• if the #fav column is exclusively updated from the Action Chains plugin, the best solution is to add another action to the the same chain that updates a custom date column together with the #fav column
• otherwise, you can use the Last Modified plugin. You also need a custom date column for this.

[Comfy.n]

Originally Posted by capink

I am not sure I understand what you want to do? From what I gather you want to store the date at which the #fav column is changed for sorting purposes?

• otherwise, you can use the Last Modified plugin. You also need a custom date column for this.

While writing this post, I remembered that the Last Modified plugin could do something like what I intend, so I set it to modify the custom column #fav.

Then I reverted that setting (leaving it to Calibre decide whether the title is modified when changing the custom value for #fav) and I noticed it actually does that.

So, if I sort the titles by the last modified column after changing the #fav value, I'm able to know what title was last added to "my favourites"... unless there is any other type of modification.

But I think I wanted to have something extra besides sorting. For instance: to be able to search/filter "what titles were added to my favourites during the pandemics lockdown". something like that

[Comfy.n]

Originally Posted by capink

I am not sure I understand what you want to do? From what I gather you want to store the date at which the #fav column is changed for sorting purposes?

• if the #fav column is exclusively updated from the Action Chains plugin, the best solution is to add another action to the the same chain that updates a custom date column together with the #fav column

I'll try that, thank you

[capink]

Originally Posted by Comfy.n

While writing this post, I remembered that the Last Modified plugin could do something like what I intend, so I set it to modify the custom column #fav.

Again, I'm not sure I am following you here. You said #fav is a yes/no column. Last Modified plugin can only modify custom date columns, so it would not be able to modify #fav. What it can do is link a custom date column to the #fav column (i.e whenever the value of #fav is changed, the custom date column is updated).

Originally Posted by Comfy.n

But I think I wanted to have something extra besides sorting. For instance: to be able to search/filter "what titles were added to my favourites during the pandemics lockdown". something like that

You can do this with the Last Modified approach I described above by using the following search:

#my_custom_date_column:>2020 AND #my_custom_date_column:<2022

Note: The same search applies for the Action Chains approach.

[Comfy.n]

Originally Posted by capink

I am not sure I understand what you want to do? From what I gather you want to store the date at which the #fav column is changed for sorting purposes?

• if the #fav column is exclusively updated from the Action Chains plugin, the best solution is to add another action to the the same chain that updates a custom date column together with the #fav column

I think you hit the bull's-eye here but I haven't tested it yet

[Comfy.n]

Wheeeeee, that was much simpler than I thought

As i'm quite new to Actions Chain PI, I hadn't noticed the "Set to current time" option.

Also, I think that, as I was used to bring up the Edit Metadata dialogue to set #fav value to 'yes', and only recently have started using just the shortcut key assigned to that Action, I didn't even consider including another action to the chain.

I thought this would only be feasible by adding some mysterious template language code to a custom column built from other columns.

[Comfy.n]

Originally Posted by capink

[*]otherwise, you can use the Last Modified plugin. You also need a custom date column for this.

oh, now I see...

Only now I understood how the Last Modified PI could accomplish that, as well.
I think this is probably the best solution, as long as I don't need any other actions in that chain.

[ownedbycats]

While this seems to be resolved, the Audit Log plugin might also be of interest.

[Comfy.n]

Originally Posted by ownedbycats

While this seems to be resolved, the Audit Log plugin might also be of interest.

sure, I hadn't thought of AL.

now I saw that it keeps change records just for the built-in columns

should be useful for other inquiries

edit: sorry, I've just noticed that I had it activated only for standard columns!

[BetterRed]

Originally Posted by Comfy.n

sure, I hadn't thought of AL.

now I saw that it keeps change records just for the built-in columns should be useful for other inquiries

Nope - for 11 standard columns (those that are user modifiable) and the custom columns

BR

[Comfy.n]

Originally Posted by BetterRed

Nope - for 11 standard columns (those that are user modifiable) and the custom columns

BR

I've read that on the plugin page... (that it records everything) but for some reason, in my library AL isn't recording the changes in custom columns.

edit: sorry, I've just noticed that I had it activated only for standard columns!

[BetterRed]

Originally Posted by Comfy.n

edit: sorry, I've just noticed that I had it activated only for standard columns!

I think I may have made the same mistake, that's why I noticed what you wrote.