Originally Posted by Narcio
In the second paragraph you said that you think its unnecessary for a merging plugin to allow a user to look and choose between metadata from either of the potential duplicate books. I think this actually would be a useful option, and a merge plugin like what you described with this feature would solve 99% of my problems before they happened.
My concern with trying to offer flexible options for merging metadata would be coming up with a UI design which doesn't make it all too horribly complicated to use.
Not that I would completely ignore metadata with an initial plugin version of course (at risk of sounding like I am writing this here but I'm not - well not yet at least!). Perhaps a few (state persisted) checkboxes could give a little more control/flexibility over what you have in Calibre today.
For instance I know Starson17 loves and defends this behaviour, but I disagree with the concept of merging comments where they differ (rather than just where there are none). There are also scenarios where people do not want to merge tags. I think these two stand in isolation from the rest of merging metadata, as everything else is considered as a "replace if empty".
Starson17 was kind enough to put in a "merge formats only" option into Calibre to replace my own local patching of the code. I think this smart merge plugin could just have a few checkboxes in it giving options like "Merge formats only" and if unchecked some granular choices of merge behaviour for the comments and tags fields. I think perhaps something like that would satisfy the 98% scenario.
You could potentially also consider covers - should the user be able to choose which of multiple covers should survive, or should it just that of the "master" (first selected record chosen before starting the merge operation).
It's a slippery slope and a challenge I think to find the right balance between keeping the merge sufficiently simple and non-intimidating versus flexibility. The existing merge operations in calibre choose the "simple" route, with some flexibility provided by mutually exlusive merge menu options. I would like a smart merge plugin to act as a superset of those in a single dialog. A power user who knows that they want to do a merge copy or whatever can still use the existing calibre menu options, but anyone else who wants a bit more control and assistance with understanding which format of multiple to keep etc could use the smart merge plugin.
As with a number of my posts, it is just me thinkout out loud at this point... I'm glad you are finding the duplicates plugin useful anyways.