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More => Old Versions => Media Center 16 (Development Ended) => Topic started by: MarkCoutinho on August 27, 2011, 03:24:08 pm

Title: Home made expression column: where is it?
Post by: MarkCoutinho on August 27, 2011, 03:24:08 pm
I've made a pretty simple column with the 'Add Expression Column' tool. I called it Lyricsvault Numbers. It's in the view of a playlist.
However: if I want to add this column in the view of another playlist it's not listed between all the columns.
Do I have to add it manually there too? I'd say it should be listed between all the other columns.
Title: Re: Home made expression column: where is it?
Post by: rick.ca on August 27, 2011, 03:56:29 pm
An Expression Column is part of the view itself. As such, it cannot be added to another view, nor would it be logical to do so. If you want the same information available in other places (e.g., other views, captions, Categories, Info Panels or other expressions), it should be saved as an Expression Field. You can create one by adding a field using Options > Library & Folders > Manage Library Fields > Add New Field.
Title: Re: Home made expression column: where is it?
Post by: MarkCoutinho on August 27, 2011, 04:32:04 pm
Mmm... Okay, got that.
As I've invested an immense lot of work to fill that column (18,000 fields filled): how can I copy the contents of that express column into the newly made Expression Field?
Title: Re: Home made expression column: where is it?
Post by: rick.ca on August 27, 2011, 05:13:33 pm
Sorry, I don't understand. It's not possible to expend any effort filling an Expression Column. The column is filled by the expression. All you need to do is use the same expression in an Expression Field.
Title: Re: Home made expression column: where is it?
Post by: MarkCoutinho on August 27, 2011, 05:25:33 pm
I don't understand the word 'expend', but this is my situation:
- I've made an Expression Column called 'X' and filled it with data (numbers)
- like you suggested I just made a new Field called 'Y' (as I should have done in the first place)

What I want is this:
- copy all the data from 'X' to 'Y'

Is it possible (please, please say yes...) and if yes: how should I do that?
Title: Re: Home made expression column: where is it?
Post by: MrC on August 27, 2011, 06:00:24 pm
Hi Mark,

If you're trying to get a copy the contents of one field to another, you can use Library Tools > Move & Copy Fields.

Or, you can enter an expression directly into a field (preceded by an equal sign "=" to set a field value.  This can of course be done for one or more files.

Copy from an expression column to another doesn't work, as what would be the target, say, if an expression column was created from two different fields?

Rick.ca mentioned you can create a new field, whose value is based on an expression.  Just copy your existing expression from the playlist you have now, and paste that expression into the new field you create.  Then, just display this "field" by adding a new column in any view.  The calculated data is what will be displayed.

See: http://wiki.jriver.com/index.php/File_Properties_%28tags%29 for more info.
Title: Re: Home made expression column: where is it?
Post by: rick.ca on August 27, 2011, 06:45:01 pm
I've made an Expression Column called 'X' and filled it with data (numbers)

There's something else going on here. This is the second time you've indicated you're entering data into an Expression Column. That's not normally possible, and certainly not what it's intended for. It's meant to display a calculated result. Under at least one circumstance, however, it is possible to edit values in an expression column. That's when the expression simply refers to one other field. In that case, the result can be edited, and the result is to change the value of the source field.

So I wonder if your Expression Column 'X' is simply referring to some other field 'W'. If so, that's where your data is. But if that's the case, 'X' nor Expression Field 'Y' are serving any purpose. It would be helpful to know exactly what the expression is, so we might understand what's going on. :-\ 
Title: Re: Home made expression column: where is it?
Post by: MarkCoutinho on August 28, 2011, 01:50:03 am
Hi Mark,

If you're trying to get a copy the contents of one field to another, you can use Library Tools > Move & Copy Fields.

Or, you can enter an expression directly into a field (preceded by an equal sign "=" to set a field value.  This can of course be done for one or more files.

Copy from an expression column to another doesn't work, as what would be the target, say, if an expression column was created from two different fields?

Rick.ca mentioned you can create a new field, whose value is based on an expression.  Just copy your existing expression from the playlist you have now, and paste that expression into the new field you create.  Then, just display this "field" by adding a new column in any view.  The calculated data is what will be displayed.

See: http://wiki.jriver.com/index.php/File_Properties_%28tags%29 for more info.

Thanks for the suggestions but they won't do:
- Move & Copy fields: my column X isn't mentioned in the wizard (probably because it's a Expression Column)
- set field value: same
- copy/paste manually can indeed. However: I hope it can be automated as I've filled 18,000 records...
Title: Re: Home made expression column: where is it?
Post by: MarkCoutinho on August 28, 2011, 01:57:27 am
There's something else going on here. This is the second time you've indicated you're entering data into an Expression Column. That's not normally possible, and certainly not what it's intended for. It's meant to display a calculated result. Under at least one circumstance, however, it is possible to edit values in an expression column. That's when the expression simply refers to one other field. In that case, the result can be edited, and the result is to change the value of the source field.

So I wonder if your Expression Column 'X' is simply referring to some other field 'W'. If so, that's where your data is. But if that's the case, 'X' nor Expression Field 'Y' are serving any purpose. It would be helpful to know exactly what the expression is, so we might understand what's going on. :-\ 
And yet I do have a field in which I can manually fill in numbers. I wanted to send with this post two printscreens in which you can see the socalled X field (Lyricsvault artiestennummer) and Column Y (Lyricsvault nrs) but I don't know how to do it.
So I'll explain what the Expression Column's expression is which makes it possible for me to edit it. It just states [Custom].
That's it.
I take it that still doesn't make it possible to copy the contents of that field (of ALL records in one time) to the newly made Field?
Title: Re: Home made expression column: where is it?
Post by: rick.ca on August 28, 2011, 03:29:58 am
Quote
It just states [Custom].

I have no idea why, but that's your source field. Display a column for [Custom] beside the expression column, and satisfy yourself the data is identical. If I understand you correctly, you created a field [Lyricsvault nrs], and that's where you would like to copy the data. Select all records and that column (click on the first record in that column, then Ctrl-A to select all records). Press F2 for edit mode and enter =[Custom]. Satisfy yourself all the data has been copied. Then edit [Custom] to remove the data.

The Wiki says [Custom] is a "general use custom field." That suggests some circumstance in which the program uses is as such—perhaps where the user should specify a field but doesn't. Or maybe it's a relic from the past. It would be nice if it would explain what that circumstance is.
Title: Re: Home made expression column: where is it?
Post by: MarkCoutinho on August 28, 2011, 06:11:58 am
Yep, that custom-thing was it.
Thanks: I've copied it now to my new Field. And I've learned the hard way what the difference is between an expression column and a Field.
Title: Re: Home made expression column: where is it?
Post by: MrC on August 28, 2011, 09:52:15 am
The Wiki says [Custom] is a "general use custom field." That suggests some circumstance in which the program uses is as such—perhaps where the user should specify a field but doesn't. Or maybe it's a relic from the past. It would be nice if it would explain what that circumstance is.

I was thinking these fields were imported/created from tracks created by, say EAC, which provides up to 4 Custom fields.