Metadata plugboard problem

[Phssthpok]

I use rating = 5 for books I have proofed and corrected. I'm trying to create a metadata plugboard which will flag this up in the filename, and tried this:

{rating:contains(5,✓ ,)}{title}

What I get is "✓Title" instead of the expected "✓ Title". Replacing the space after "✓" with a NBSP makes no difference. So I tried escaping the space with a backslash:

{rating:contains(5,✓\ ,)}{title}

and now I get "✓ itle" -- the space is there, but it overwrites the first character of the title...

Can anyone explain what is going on here, and how I can get both a space and the first character of the title to appear?

[Katja_hbg]

Spaces will not be ignored when you use unbreakable spaces.
I did it this way: in word key alt together with 0160 on the number block
Copy that from word into plugboard.
Sounds stupid, but works.

[davidfor]

@Phssthpok: When I look at that I think: "Where are the quotes?" Are you sure you shouldn't have quotes around the replacement string? I would expect a trailing space to be stripped off in without them.

And in the last case, I wonder if the "t" hasn't actually been removed, but whatever you are viewing it with is seeing "\t" and substituting a tab character.

[chaley]

Originally Posted by Phssthpok

Can anyone explain what is going on here, and how I can get both a space and the first character of the title to appear?

Leading and trailing spaces in the result of a template expression are stripped (removed) before that result is further processed. That is one reason the prefix and suffix options exist -- they are applied if the result is non-empty after being stripped, and without further stripping.

Use

{rating:contains(5,✓,)|| }{title}

@davidfor: he is using Single Function Mode, which doesn't use quoting. This can lead to ambiguities, which is why I prefer Template Program Mode or General Program Mode, depending on the task.

[Phssthpok]

Originally Posted by chaley

Leading and trailing spaces in the result of a template expression are stripped (removed) before that result is further processed. That is one reason the prefix and suffix options exist -- they are applied if the result is non-empty after being stripped, and without further stripping.

Use

{rating:contains(5,✓,)|| }{title}

Aha! Thank you very much, problem solved! (I didn't see anything in TFM about template results being trimmed...?)

I'm still puzzled about losing the first letter of the title with a backslash-escaped space though...

[Phssthpok]

Originally Posted by Katja_hbg

Spaces will not be ignored when you use unbreakable spaces.
I did it this way: in word key alt together with 0160 on the number block
Copy that from word into plugboard.
Sounds stupid, but works.

But they are ignored. I tried it by pasting in an NBSP character, exactly as you described (except I copied mine from the Calibre editor's special characters panel). I presume all \s characters (which includes NBSP) are trimmed.

[Phssthpok]

Originally Posted by davidfor

And in the last case, I wonder if the "t" hasn't actually been removed, but whatever you are viewing it with is seeing "\t" and substituting a tab character.

It's the first character of the book title, not the first character of the word "title". It was actually the letter R in the case of the book I was experimenting with.

[davidfor]

Originally Posted by Phssthpok

It's the first character of the book title, not the first character of the word "title". It was actually the letter R in the case of the book I was experimenting with.

Of course.

[chaley]

Originally Posted by Phssthpok

I'm still puzzled about losing the first letter of the title with a backslash-escaped space though...

This happens because of the order of evaluation. First the individual templates are evaluated. In your case the first template will end with a \ because the space is stripped. The results are then concatenated. It seems that the title in your example begins with an R. If we assume the title is Ringworld then the result is

✓\Ringworld

The sequence \R is a carriage return, which gets converted by the output function to a space, resulting in

✓ ingworld

Other characters would behave differently, perhaps disappearing or perhaps generating some other output.

FWIW: backslashes in Single Function Mode can have strange behavior. Sometimes they are really escapes and sometimes they aren't. You should avoid them or use one of the other modes instead.

[Phssthpok]

Originally Posted by chaley

This happens because of the order of evaluation...

Aha! Many thanks, now I finally understand...

FWIW: backslashes in Single Function Mode can have strange behavior. Sometimes they are really escapes and sometimes they aren't. You should avoid them or use one of the other modes instead.

Yes, I think I've learnt that lesson