Demo: Dynamic Citations¶Frank Bennett
This page demonstrates dynamic citation editing in the browser. The underlying code was prepared in response to work by Derek Sifford. Click on the chevrons to open a citation widget, select one or more references, and press “Save” to add them to the document. Use the pulldown list above to transform the document to another style. Click on the “More” button below for information on running the code locally, and on adapting it for use in production.
One of the main purposes of this page is to provide a worked example for developers. A good way to explore the way it all works is to run the page locally. Here is how to set that up.
- Fetch the repo
citeproc-jsdocumentation project and enter its top-level directory:
git clone https://github.com/Juris-M/citeproc-js-docs.git --recursive cd citeproc-js-docs
- Build the docs
The following command should work:
- Run a server using
The built page uses
XMLHttpRequest()calls, so it must be viewed through a web server. To run a simple server using
node.js, an incantation like this should do the trick:
npm install -g http-server http-server _build/html
Source File Overview¶
- The CSL processor for Citation Style Language (CSL) stylesheets.
- A middleware module that connects the processor, which runs in a web worker, with the DOM of the page.
- A web worker to run the processor. This supplies data I/O methods required by the processor, and implements a simple messaging interface for purposes of the demo page.
- CSS code for the documentation, including the demo pages.
- A few sample items for the editing demo, in CSL JSON format.
- The standard CSL locales.
- The CSL styles used in the demo. The “JM” styles are from the Juris-M styles repository, and have modular legal style support. The remainder are from the official CSL repository, which feeds the Zotero styles distribution site.
A set of legal style modules resides here. For information on legal
style support in CSL-M (multilingual-enhanced CSL) see the Juris-M Style Editor (GitHub account required).
Here are some notes on things relevant to deployment:
- The class should be instantiated as
citesupport. The event handlers expect the class object to be available in global context under that name.
true, the stored object
citationIdToPosmaps citationIDs to the index position of fixed “pegs” in the document that have class
citeme. In the demo, this map is stored in localStorage, and is used to reconstruct the document state (by reinserting
class:citationspan tags) on page reload.
false, the document is assumed to contain
class:citationspan tags, and operations on
citemenodes will not be performed. In non-demo mode,
citationIdToPoscarries the index position of citation nodes for good measure, but the mapping is not used for anything.
spoofDocument()function brings citation data into memory. In the demo, this data is held in localStorage, and
spoofDocument()performs some sanity checks on data and document. For a production deployment, this is the place for code that initially extracts citation data the document (if, for example, it is stashed in data-attributes on citation nodes).
setCitations()function is where citation data for individual citations would be saved, at the location marked by NOTE.
- The user-interface functions
citationWidget()are simple things cast for the demo, and should be replaced with something a bit more functional.
SafeStorageclass should be replaced (or subclassed?) for deployment with a class that provides the same methods. If the citation objects making up
citationByIndexare stored directly on the
class:citationspan nodes, the getter for that value should harvest the values from the nodes, and store them on
config.citationByIndex. The setter should set
config.citationByIndexonly, relying on other code to update the node value.
- Probably some other stuff that I’ve overlooked.
The heavy lifting is done by the CSL processor, which runs in a separate thread as a web worker. Only the document-facing interface of the worker is described here: it should not be necessary to tangle with the internals of the worker itself. Its only idiosyncracy is that it assigns note numbers (reflected in the return) in citation sequence—in contrast to word processor context, it assumes that the only footnotes in the document are those generated automatically by a note style. If that is not true in your context, you will want to disable that behavior, and do whatever is necessary on document side to extract real note numbers for delivery to the processor.
The worker is controlled by two methods,
callRegisterCitation(), each with a corresponding message and
This method is used on page load, on change of style, and when all citations have been removed from the document. The
styleIDargument is mandatory. If
localeIDis not provided, the processor will be configured with the
citesupport.callInitProcessormethod implicitly accesses the
config.citationByIndexarray, which must be accessible in page context. If the array is empty, the processor will be initialized without citations. If the array contains citations, the processor will be initialized to that document state, and return an array of arrays as
rebuildData, for use in reconstructing citations in the document text. Each sub-array contains a citation ID, a note number, and a citation string. For example, if the
styleIDis for a
notestyle, and if
config.citationByIndexyields the citations “Wurzel Gummidge (1990)” and “My Aunt Sally (2001),” the
rebuildDatastructure would look like this:
[ [ "lu7Tu3ki", "1", "Wurzel Gummidge (1990)" ], [ "ko4aNoo9", "2", "My Aunt Sally (2001)" ] ]
citesupport.callRegisterCitation(citation, preCitations, postCitations)
This method is used to add or to edit citations. All three arguments are mandatory.
citationis an ordinary citation object as described above.
postCitationsare arrays of arrays, in which each sub-array is composed of a citation ID and a note number. For example, if a note citation is to be inserted between the “Wurzel Gummidge” and “Aunt Sally” citations in the example above, these would have the following form:
preCitations = [ [ "lu7Tu3ki", "1" ] ]; postCitations = [ [ "ko4aNoo9", "3" ] ];
Notice the change to the note number: the processor registers note numbers for use in back-references, but maintenance of correct note numbering must be handled in document-side code.
citesupport.callRegisterCitationmethod returns two values from the processor:
citationByIndex(described above) and
citations. The latter is an array of one or more arrays, each composed of a citation position index, a string, and a citation ID. For example, the return value to insert a citation “Calvin (1995); Hobbes (2016)” between the “Wurzel Gummidge” and “My Aunt Sally” citations would look something like this:
[ [ 1, "Calvin (1995); Hobbes (2016)", "Ith7eg8T" ] ]
Note that the return value might contain updates for multiple citations.