Combining two custom columns?

[pg111]

Hi,

I have a question but I apologize if this is not the proper place to ask. If so, plse kindly let me know where I should ask my question. Many thanks in advance.

Is it possible to create a custom column where you can enter new text that complements an existing set of defined values?

For instance, if I have a column with values A, B, and C, I may want to enter a value D which will be added to the existing list. Is it possible in calibre? I cannot see any such option.

Many thanks in advance for any help.

Patrik

[chaley]

Moderator Notice
Made into its own thread

[chaley]

Originally Posted by pg111

Hi,

I have a question but I apologize if this is not the proper place to ask. If so, plse kindly let me know where I should ask my question. Many thanks in advance.

Is it possible to create a custom column where you can enter new text that complements an existing set of defined values?

For instance, if I have a column with values A, B, and C, I may want to enter a value D which will be added to the existing list. Is it possible in calibre? I cannot see any such option.

Many thanks in advance for any help.

Patrik

The only way I can think of to do this is to create two columns, one for the values to add and one to display the merged columns. The first would be text, tags like. The second would be column built from other columns, behaves like tags. The second's template would be something like this:

program:list_union(field('tags'), field('#mytextmult'), ',')

Replace the column lookup names with the ones from your library.

If you want the list sorted then use list_sort:

program:list_sort(list_union(field('tags'), field('#mytextmult'), ','), '0', ',')

[pg111]

Originally Posted by chaley

The only way I can think of to do this is to create two columns, one for the values to add and one to display the merged columns. The first would be text, tags like. The second would be column built from other columns, behaves like tags. The second's template would be something like this:

program:list_union(field('tags'), field('#mytextmult'), ',')

Replace the column lookup names with the ones from your library.

If you want the list sorted then use list_sort:

program:list_sort(list_union(field('tags'), field('#mytextmult'), ','), '0', ',')

Thanks, Charles.

And how or where do I use the

program:list_sort(list_union(field('tags'), field('#mytextmult'), ','), '0', ',')

line?

Sorry, I'm a beginner in customizing calibre.

Many thanks in advance for your answer.

[chaley]

Originally Posted by pg111

Thanks, Charles.

And how or where do I use the

program:list_sort(list_union(field('tags'), field('#mytextmult'), ','), '0', ',')

line?

Sorry, I'm a beginner in customizing calibre.

Many thanks in advance for your answer.

When you create a custom column built from other columns, one of the things you must provide is the "template". In this instance the template is a kind of program telling calibre what to do with metadata. There is a lot more in the manual The calibre template language.

[Terisa de morgan]

If you don't mind, let's go a step back: You have column A which admits three values. Is that a predefined column or an existing column?

If it is a predefined one, you would have to go with chaley solution:
1.- Create custom column B, which will have only the new values
2.- Create custom column C (composite created based on other columns), and the function will be the function chaley has written before.

So, now you will have to introduce values in A or B depending of the value and C will show always the proper value.

If A is a custom column, the easiest way to do it is to modify column A to add new values.

I guess it will be predefined, but only to be sure.

[chaley]

Originally Posted by Terisa de morgan

If you don't mind, let's go a step back: You have column A which admits three values. Is that a predefined column or an existing column?

Always a good idea to ask what the end goal is.

[pg111]

Hi,

I have another pending question.

I have created a custom Foreword column in which it is possible to specify who wrote a foreword to the currently selected book.

When I right-click on the value in it and select Manage Foreword, I would like to get the same dialog box as when I right-click Author's name and select Manage Author. In other words I would like to handle Foreword as if it were an Author's name.

How can I get this result?

Many thanks in advance.

[chaley]

Originally Posted by pg111

Hi,

I have another pending question.

I have created a custom Foreword column in which it is possible to specify who wrote a foreword to the currently selected book.

When I right-click on the value in it and select Manage Foreword, I would like to get the same dialog box as when I right-click Author's name and select Manage Author. In other words I would like to handle Foreword as if it were an Author's name.

How can I get this result?

Many thanks in advance.

The general answer is "You can't". A custom "contains names" column doesn't have a "sort" field.

However, right-clicking on the "Forward" label in the tag browser will give you a "Manage" dialog that might solve the problem.

[pg111]

Originally Posted by Terisa de morgan

If you don't mind, let's go a step back: You have column A which admits three values. Is that a predefined column or an existing column?

If it is a predefined one, you would have to go with chaley solution:
1.- Create custom column B, which will have only the new values
2.- Create custom column C (composite created based on other columns), and the function will be the function chaley has written before.

So, now you will have to introduce values in A or B depending of the value and C will show always the proper value.

If A is a custom column, the easiest way to do it is to modify column A to add new values.

I guess it will be predefined, but only to be sure.

Thanks, Terisa de morgan. I'm speaking of a custom column. In the list of custom column formats available I cannot see any format that allows me to modify an existing list of existing values on the fly. I mean everytime I enter C (or D, or E, and so on) in the column cell, the new value is added to the existing list.

That is what I'm in search of.

Let us say I have a list of book types. Initially it is a set of predefined values but later on I realize I had not thought of one specific type and would like to add it to my existing list. How can I do to create a custom column that allows me to do so?

I hope I made it clearer.

Many thanks in advance for any help.

[chaley]

Originally Posted by pg111

Let us say I have a list of book types. Initially it is a set of predefined values but later on I realize I had not thought of one specific type and would like to add it to my existing list. How can I do to create a custom column that allows me to do so?

Is there some reason you don't want to add the new type as one of the possible pre-defined values? You do that by editing the column definition.

[theducks]

Originally Posted by pg111

Thanks, Terisa de morgan. I'm speaking of a custom column. In the list of custom column formats available I cannot see any format that allows me to modify an existing list of existing values on the fly. I mean everytime I enter C (or D, or E, and so on) in the column cell, the new value is added to the existing list.

That is what I'm in search of.

Let us say I have a list of book types. Initially it is a set of predefined values but later on I realize I had not thought of one specific type and would like to add it to my existing list. How can I do to create a custom column that allows me to do so?

I hope I made it clearer.

Many thanks in advance for any help.

In the place you CREATED the custom (predefined tags) column: Select that column from the list:click the EDIT button on the right.
Note that you can't change the TYPE once created, but just about anything else can be updated. BEWARE of changing the lookup name if you have used it in plugins or scripts, Calibre can't suss out all uses, so those can now fail.

[pg111]

Originally Posted by chaley

The general answer is "You can't". A custom "contains names" column doesn't have a "sort" field.

However, right-clicking on the "Forward" label in the tag browser will give you a "Manage" dialog that might solve the problem.

Precisely it does not.

Plse find hereattached two screenshots:

One is for Manage Authors dialog box.

The other is for Manage Foreword (Préface in French) dialog box.

How can I get the latter behave similar to the first one?

Many thanks in advance.

[chaley]

Originally Posted by pg111

Precisely it does not.

Plse find hereattached two screenshots:

One is for Manage Authors dialog box.

The other is for Manage Foreword (Préface in French) dialog box.

How can I get the latter behave similar to the first one?

Many thanks in advance.

You can't. The Authors column is special, having value, sort and link. The names-like column has only value.

[pg111]

Originally Posted by chaley

You can't. The Authors column is special, having value, sort and link. The names-like column has only value.

Thanks for your answer. I see clearly now. That seems to be a serious limitation for me. Unless I find an alternate solution to this problem I may give up the whole idea of using calibre to manage both my book libraries and I may revert to my initial project about a calibre-BookCAT route (which would not prevent me to keep using calibre for my eBooks).

Thanks again.