# CSL deployment idea

**URL:** <https://discourse.citationstyles.org/t/csl-deployment-idea/274>\
**Category:** CSL Development\
**Created:** [June 18, 2007, 12:15am UTC](https://discourse.citationstyles.org/t/csl-deployment-idea/274 "2007-06-18T00:15:07Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![Bruce\_D\_Arcus1](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@Bruce\_D\_Arcus1](https://discourse.citationstyles.org/u/Bruce_D_Arcus1)\
**Post date:** [June 18, 2007, 12:15am UTC](https://discourse.citationstyles.org/t/csl-deployment-idea/274/1 "2007-06-18T00:15:07Z")

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I don’t know a ton about web servers and such, but in deploying CSL,  
would it make sense to recommend that all CSL files have at the  
location their URI resolves to …

a) the XML (text/xml) style itself  
b) an HTML representation with output examples

…? So if given a URI of “[http://zotero.org/styles/pyschology/apa](http://zotero.org/styles/pyschology/apa)”, a  
browser would display the web page, while a citation processor would  
just download (and cache) the style directly?

Bruce

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**Author:** ![Dan\_Stillman](https://avatars.discourse-cdn.com/v4/letter/d/ecb155/32.png) [@Dan\_Stillman](https://discourse.citationstyles.org/u/Dan_Stillman)\
**Post date:** [June 18, 2007, 6:59am UTC](https://discourse.citationstyles.org/t/csl-deployment-idea/274/2 "2007-06-18T06:59:43Z")

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This could be done with HTTP/1.1 Content Negotiation:  
[http://httpd.apache.org/docs/2.0/content-negotiation.html](http://httpd.apache.org/docs/2.0/content-negotiation.html)

There would be two files in the directory, apa.html and apa.csl.  
Browsers, which send text/html in the Accept header, would get the HTML.  
Citations processors would send text/xml (or application/x-csl, or  
whatever) in the Accept header (say, using  
XMLHTTPRequest.setRequestHeader(), as Zotero would do) and get the CSL  
file, assuming the server had been configured to serve .csl files with  
the appropriate content type.

Of course, citation processors could also just append “.csl” to the URI  
automatically, and if the idea was for CSL files to be available in a  
distributed manner, that’d probably have to be the standard behavior, as  
configuring MIME types and content negotiation settings might not be  
possible for all authors (depending on the server setup).

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**Author:** ![Bruce\_D\_Arcus1](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@Bruce\_D\_Arcus1](https://discourse.citationstyles.org/u/Bruce_D_Arcus1)\
**Post date:** [June 18, 2007, 11:41am UTC](https://discourse.citationstyles.org/t/csl-deployment-idea/274/3 "2007-06-18T11:41:02Z")

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Hi Dan,

> This could be done with HTTP/1.1 Content Negotiation:  
> [Content Negotiation - Apache HTTP Server](http://httpd.apache.org/docs/2.0/content-negotiation.html)

Yes, that’s what I had in mind, having known about it through the RDF  
stuff. I just wasn’t sure about the practical deployment issues. So  
…

[…]

> Of course, citation processors could also just append “.csl” to the URI  
> automatically, and if the idea was for CSL files to be available in a  
> distributed manner, that’d probably have to be the standard behavior, as  
> configuring MIME types and content negotiation settings might not be  
> possible for all authors (depending on the server setup).

… what would be the precise upshot? Are you suggesting we really  
can’t suggest a human-readable (HTML) representation be resolvable  
using the URI for the style?

Bruce

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**Author:** ![Dan\_Stillman](https://avatars.discourse-cdn.com/v4/letter/d/ecb155/32.png) [@Dan\_Stillman](https://discourse.citationstyles.org/u/Dan_Stillman)\
**Post date:** [June 18, 2007, 5:48pm UTC](https://discourse.citationstyles.org/t/csl-deployment-idea/274/4 "2007-06-18T17:48:02Z")

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No, I’m not suggesting that. If given an HTML file without an extension,  
Apache, at least, will still send the file as text/html, thanks to  
mod\_mime\_magic, even without using content negotiation. So we could just  
have the HTML file be “apa” and the CSL file be “apa.csl”, and as long  
as citation processors knew to append “.csl” to the URI when requesting  
the CSL file, it’d be fine.

The content negotiation approach would be a bit more elegant, but it  
doesn’t provide much benefit that I can think of and might limit who  
could host a CSL file.

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**Author:** ![Bruce\_D\_Arcus1](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@Bruce\_D\_Arcus1](https://discourse.citationstyles.org/u/Bruce_D_Arcus1)\
**Post date:** [June 18, 2007, 7:09pm UTC](https://discourse.citationstyles.org/t/csl-deployment-idea/274/5 "2007-06-18T19:09:49Z")

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OK, sounds good.

BTW, apropos of this, I just bcc-ed you on a reply to a colleague of  
mine who is loving Zotero, and now wanting to use the style for his  
particular journal (he got tripped up because wanting to manually  
correct the formatting in the bibliography fields).

What I’d to be able to do sometime soon is:

1. load a CSL for his journal onto the web
2. send him the URI for it, which he pastes into a field in Zotero

The rest (downloading, caching, etc.) would happen automatically.

Or something like that 😉

Bruce

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**Author:** ![Dan\_Stillman](https://avatars.discourse-cdn.com/v4/letter/d/ecb155/32.png) [@Dan\_Stillman](https://discourse.citationstyles.org/u/Dan_Stillman)\
**Post date:** [June 19, 2007, 6:48am UTC](https://discourse.citationstyles.org/t/csl-deployment-idea/274/6 "2007-06-19T06:48:55Z")

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Some questions/thoughts:

1. How do you see updates being handled? Via an XML-based index file  
that contains version/timestamp information for all CSL files on a site?

2. Are the location and name of the index file specified in the CSL, or  
are they implicit (say, a default file name in the same directory of any  
already downloaded files, or a walk up the paths until one is found (to  
handle a repository with a hierarchical directory structure))? For  
various reasons, some method of determining the index file from a given  
CSL file would be helpful.

3. What’s the mechanism for downloading all styles from a repository? I  
imagine you’d be able to specify either a single CSL file or an entire  
repository (which might be the URL of the index file). If you point to  
the index file, can you pick and choose, or do you get them all? (This  
is a client implementation question, and I can’t guarantee that one  
approach or another would be implemented in Zotero, but I’m curious how  
you see it working.)

4. How are duplicates handled? If you post a style for your colleague to  
test, and he installs it via the URL you provide, and then the style is  
moved into the main Zotero repository (to which my Zotero client is  
subscribed by default), what happens to the installed style on his  
computer? He can just delete the old one manually, of course, but  
citation processors should probably be expected to handle 301 redirects  
correctly for both index files and CSL files and switch to the  
redirected URL (at least if it resolves to a valid index/CSL file). If  
the index file exists and specifies a CSL file URL not below its path,  
that should probably also be treated as a permanent redirect for  
existing subscribers.

- Dan

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**Author:** ![Bruce\_D\_Arcus1](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@Bruce\_D\_Arcus1](https://discourse.citationstyles.org/u/Bruce_D_Arcus1)\
**Post date:** [June 19, 2007, 12:01pm UTC](https://discourse.citationstyles.org/t/csl-deployment-idea/274/7 "2007-06-19T12:01:42Z")

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> > What I’d to be able to do sometime soon is:
> > 
> > 1. load a CSL for his journal onto the web
> > 2. send him the URI for it, which he pastes into a field in Zotero
> > 
> > The rest (downloading, caching, etc.) would happen automatically.
> 
> Some questions/thoughts:
> 
> 1. How do you see updates being handled? Via an XML-based index file  
> that contains version/timestamp information for all CSL files on a  
> site?

Probably. This is why we were earlier talking about using Atom. So user  
would subscribe to a repository (in a large repository, it might be one  
for their field though).

I suppose a simple way to start is to use the time-stamp in the file,  
though?

> 1. Are the location and name of the index file specified in the CSL, or  
> are they implicit (say, a default file name in the same directory of  
> any  
> already downloaded files, or a walk up the paths until one is found (to  
> handle a repository with a hierarchical directory structure))? For  
> various reasons, some method of determining the index file from a given  
> CSL file would be helpful.

Agreed. And I would say the latter. So we take the APA example. Let’s  
say we move it to your repository, and we give it the stable URI  
[http://zotero.org/styles/psychology](http://zotero.org/styles/psychology).

I would expect at the styles directory to see something like:

index.xml (probably an Atom file)  
history/  
psychology/  
index.xml  
apa.csl

Note: some tricky issues with categorizing styles sometimes, so not  
sure that’s a good idea. I’m just imagining the goal, which is the  
possibility that a repository might have hundreds, if not thousands, of  
styles. Might be better to just do:

apa.csl  
chicago.csl  
generic.xml  
history.xml  
mla.csl  
psychology.xml

So a feed per subject/field, where each file also gets tagged with  
those (from which the index file is generated).

> 1. What’s the mechanism for downloading all styles from a repository? I  
> imagine you’d be able to specify either a single CSL file or an entire  
> repository (which might be the URL of the index file). If you point to  
> the index file, can you pick and choose, or do you get them all?

I think ideally both.

I’d imagine a user would subscribe to a repository or repository  
section just as they would a news feed. Perhaps they get a list of all  
styles in that feed/repo, and can either select all or choose  
individual styles to … I don’t know the verb … activate (?).

> (This is a client implementation question, and I can’t guarantee that  
> one  
> approach or another would be implemented in Zotero, but I’m curious how  
> you see it working.)

Right.

> 1. How are duplicates handled? If you post a style for your colleague  
> to  
> test, and he installs it via the URL you provide, and then the style is  
> moved into the main Zotero repository (to which my Zotero client is  
> subscribed by default), what happens to the installed style on his  
> computer? He can just delete the old one manually, of course, but  
> citation processors should probably be expected to handle 301 redirects  
> correctly for both index files and CSL files and switch to the  
> redirected URL (at least if it resolves to a valid index/CSL file). If  
> the index file exists and specifies a CSL file URL not below its path,  
> that should probably also be treated as a permanent redirect for  
> existing subscribers.

I agree this is a detail that’s important. You probably have a better  
sense than I. And perhaps the Atom spec might be helpful?

Bruce

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<div class="post-metadata">

**Author:** ![Bruce\_D\_Arcus1](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@Bruce\_D\_Arcus1](https://discourse.citationstyles.org/u/Bruce_D_Arcus1)\
**Post date:** [June 19, 2007, 1:05pm UTC](https://discourse.citationstyles.org/t/csl-deployment-idea/274/8 "2007-06-19T13:05:46Z")

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Ah, sure enough; API support for Atom feed reading:

[http://developer.mozilla.org/en/docs/Feed\_content\_access\_API](http://developer.mozilla.org/en/docs/Feed_content_access_API)

Bruce

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**Author:** ![Bruce\_D\_Arcus1](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@Bruce\_D\_Arcus1](https://discourse.citationstyles.org/u/Bruce_D_Arcus1)\
**Post date:** [June 27, 2007, 11:57am UTC](https://discourse.citationstyles.org/t/csl-deployment-idea/274/9 "2007-06-27T11:57:49Z")

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Was just remembering that the Atom world had to deal with this. See:

\<[http://www.dehora.net/journal/2004/07/](http://www.dehora.net/journal/2004/07/)  
atom\_and\_cool\_uris\_dogma\_idealism\_expediency.html\>  
[http://diveintomark.org/archives/2004/05/28/howto-atom-id](http://diveintomark.org/archives/2004/05/28/howto-atom-id)

The right answer isn’t that straightforward, though we’d want to decide  
on the right policy: either one always-resolvable URI, or multiple.

Bruce