Style syntax for formatting multiple locators

[denismaier]

Some style guides, e.g. Chicago, require certain combinations of locators to be formatted differently. E.g.:

A combination of page and line locators is cited as:

p. 15, line 10

However, a combination of volume and page is not cited as "vol. 5, p. 82", but as:

5:82

I think we could handle this on a style basis, similar to the existing editortranslator collapsing. Like with a style level attribute collapse-volume-page-in-locator.

Say we have this:

"locators": [{"volume": 2}, {"page": 12}]
collapse-volume-page-in-locator="true" => "2:12"
collapse-volume-page-in-locator="false" => "vol. 2, p. 12"

Of course, there's also the question if there are other relevant combinations.

[bdarcus]

Possible there are other such examples, that would require a more general solution?

[denismaier]

Possible there are other such examples, that would require a more general solution?

There may well be. In classics and theology they have special pattern for "book, chapter, verse, line" combinations. And those may even be different for different works.

[bdarcus]

So then we'd probably want this configured in a macro at the end; no?

[denismaier]

So then we'd probably want this configured in a macro at the end; no?

Either this, or a cs:locators sibling to cs:citation. Whatever seems more convenient.

[denismaier]

While we have your attention @andras-simonyi, what do you think about this in light of your locators proposal?

[andras-simonyi]

It would be nice to see whether there are other non work-specific (i.e., not valid only for the Bible, for Plato's works etc.) examples of this kind of special rule that are relatively common in addition to the Chicago volume/page requirement. As for work-specific rules, do we want to support this? How could something like this be approached within the CSL framework?

[denismaier]

I don't know about other common combinations besides volume and page.

How could something like this be approached within the CSL framework?

Biblatex knows pagination and bookpagination fields. We could add something similar, and also locatorscheme or similar.
Or we could just make this dependent on item types. E.g. styles could suppress locator terms for items with type classic.

[bwiernik]

Note that the Chicago CSL styles appear to already have some sort of solution already not using locators, but using the volume or issue variables some item types. This works if "Collected Works, Volume 1" is entered as the item, rather than the whole "Collected Works".

If we did want do more here, I think we can handle this generally by expanding on the existing locator style syntax.

We already allow conditional tests (currently used for conditional label formatting):

<if locator="volume">
  <text variable="locator"/>
</if>
<else>
  <label variable="locator" suffix=" "/>
  <text variable="locator"/>
</else>

We need a way to specify the locator delimiter anyway. We could add cs:locator and give it a delimiter attribute for that. The delimiter attribute would indicate the delimter that comes after a locator of that type. So for example:

<if locator="volume">
  <locator delimiter=":"/>
</if>
<else>
  <locator delimiter=", ">
    <label variable="locator" suffix=" ">
  </locator>
</else>

To handle different formatting of the label depending on whether a page has a line number vs. not (e.g., 128 for a page number normally, but p. 15, line 10 if there is a line number, we could add the condition additional-locators="true" or multiple-locators="true":

<if locator="volume">
  <locator delimiter=":"/>
</if>
<else-if additional-locators="true">
  <locator delimiter=", ">
    <label variable="locator" suffix=" ">
  </locator>
</else-if>
<else-if locator="page">
  <locator/>
</else-if>
<else>
  <locator delimiter=", ">
    <label variable="locator" suffix=" ">
  </locator>
</else>

[bwiernik]

Changed the title to reflec the more general problem of formatting multiple locators

[denismaier]

Looks like there is one major caveat: volume can be part of the item metadata, or it can be one of the locators. Both situation may require different solutions.

Regarding testing behavior: I think we could add a new value "exact" for @match. This would test true if only the specified locators are present:

<if locators="volume page" match="exact">
formatting if we have volume and page, but nothing else
</if>
<else-if locators="page" match="exact">
formatting if we have only page
</else-if>
<else>
formatting in all other situations
</else>

match="exact" could be made the default when testing for locators.

[bwiernik]

I don't think that's necessary. It's covered by my example above. If there is volume+page, it will render "volume:page". If there is volume as metadata and page as locator, it will just render page.

[denismaier]

I don't think that's necessary. It's covered by my example above. If there is volume+page, it will render "volume:page". If there is volume as metadata and page as locator, it will just render page.

Ok. What if you want "p. 15, line 4", but "book 3, part 4, chapter 3, section2" should be rendered as "3:4:3:2"?
(Perhaps not a realistic scenario, though)

[denismaier]

I don't think that's necessary. It's covered by my example above. If there is volume+page, it will render "volume:page". If there is volume as metadata and page as locator, it will just render page.

Ok. What if you want "p. 15, line 4", but "book 3, part 4, chapter 3, section2" should be rendered as "3:4:3:2"?
(Perhaps not a realistic scenario, though)

Or, that might depend more on item type than on the actual presence of certain locators.