My Zotero export translator for BibTeX

bibtex.js

// See https://www.zotero.org/support/dev/translators

var zotero2bibtexTypeMap = {
	"book": "book",
	"bookSection": "incollection",
	"journalArticle": "article",
	"magazineArticle": "article",
	"newspaperArticle": "article",
	"thesis": "phdthesis",
	"letter": "misc",
	"manuscript": "unpublished",
	"patent" :"patent",
	"interview": "misc",
	"film": "misc",
	"artwork": "misc",
	"webpage": "misc",
	"conferencePaper": "inproceedings",
	"report": "techreport"
};

function getYearFromDate(date) {
	if(date.length < 4) {
		return '';
	}
	const dateRegex = /^\d{4}$/;
	const beg = date.slice(0, 4);
	if(dateRegex.test(beg)) {
		return beg;
	}
	const end = date.slice(date.length-4, date.length);
	if(dateRegex.test(end)) {
		return end;
	}
	return '';
}

const shortWords = new Set(['a', 'an', 'the', 'of', 'from']);

function getBibInfo(item) {
	const type = zotero2bibtexTypeMap[item.itemType] ?? 'misc';
	const data = {'title': item.title};
	const isArxivPaper = (item.itemType === 'preprint'
		&& item.repository.toLowerCase() === 'arxiv');

	// get authors
	const authors = [];
	let firstAuthorLastName;
	for(const creatorInfo of item.creators) {
		if(creatorInfo.creatorType === 'author') {
			if(firstAuthorLastName === undefined) {
				firstAuthorLastName = (creatorInfo.lastName ?? creatorInfo.firstName).toLowerCase();
			}
			const authorFullName = [creatorInfo.lastName, creatorInfo.firstName].join(', ');
			authors.push(authorFullName);
		}
	}
	data.authors = authors.join(' and ');

	// create label
	const year = (item.date) ? getYearFromDate(item.date) : '';
	const titleFirstWord = item.title.toLowerCase().split(/[^a-z0-9]/)
		.filter((word) => !shortWords.has(word))[0];
	const label = firstAuthorLastName + year + titleFirstWord;

	// venue
	let venueType, venue;
	if(type === 'article') {
		venueType = 'journal';
		venue = item.publicationTitle ?? item.journalAbbreviation;
	}
	else if(type === 'inproceedings') {
		venueType = 'booktitle';
		venue = item.proceedingsTitle ?? item.conferenceName;
	}
	if(venueType) {
		data[venueType] = venue;
	}

	if(year) {data.year = year;}
	if(!isArxivPaper && item.volume) {data.volume = item.volume;}
	if(!isArxivPaper && item.number) {data.number = item.number ?? item.issue;}
	if(item.pages) {
		data.pages = item.pages.replace(/[-–]+/, '--');
	}
	if(!isArxivPaper && item.publisher) {data.publisher = item.publisher;}

	// doi or url
	if(isArxivPaper && item.archiveID) {
		data.eprint = item.archiveID;
		data.archivePrefix = 'arXiv';
	}
	else if(item.DOI) {data.doi = item.DOI;}
	else if(item.url) {data.url = item.url;}

	/*
	item.abstractNote = '';
	item.uniqueFields = {};
	for(const [key, value] of Object.entries(item)) {
		Zotero.debug(`${key}: ${JSON.stringify(value)}`);
	}
	*/
	return [type, label, data];
}

function writeBibtex(type, label, data) {
	/*
	Zotero.debug(`type: ${type}`);
	Zotero.debug(`label: ${label}`);
	for(const [key, value] of Object.entries(data)) {
		Zotero.debug(`${key}: ${JSON.stringify(value)}`);
	}
	*/

	Zotero.write(`@${type}{${label},\n`);
	const lines = [];
	for(const [key, value] of Object.entries(data)) {
		lines.push(`${key} = {${value}}`);
	}
	Zotero.write(lines.join(',\n'));
	Zotero.write('\n}\n');
}

function doExport() {
	let item;
	while (item = Zotero.nextItem()) {
		//don't export standalone notes and attachments
		if (item.itemType == "note" || item.itemType == "attachment") {
			continue;
		}

		const [type, label, data] = getBibInfo(item);
		writeBibtex(type, label, data);
	}
}