/**
* Minimal XML parsing helpers — no external deps.
* These work on the PubMed XML format specifically.
*/
export function extractTag(xml: string, tag: string): string {
const re = new RegExp(`<${tag}[^>]*>([\\s\\S]*?)</${tag}>`, "i");
const m = xml.match(re);
return m ? m[1].trim() : "";
}
export function extractAllTags(xml: string, tag: string): string[] {
const re = new RegExp(`<${tag}[^>]*>([\\s\\S]*?)</${tag}>`, "gi");
const results: string[] = [];
let m: RegExpExecArray | null;
while ((m = re.exec(xml)) !== null) {
results.push(m[1].trim());
}
return results;
}
export function extractAttr(xml: string, tag: string, attr: string): string {
const re = new RegExp(`<${tag}[^>]*\\s${attr}="([^"]*)"`, "i");
const m = xml.match(re);
return m ? m[1] : "";
}
export function stripTags(xml: string): string {
return xml.replace(/<[^>]+>/g, "").trim();
}
export interface ArticleMetadata {
pmid: string;
title: string;
abstract: string;
authors: string[];
journal: string;
pubDate: string;
doi: string;
meshTerms: string[];
}
export function parseArticles(xml: string): ArticleMetadata[] {
const articles = extractAllBlocks(xml, "PubmedArticle");
return articles.map(parseOneArticle);
}
function extractAllBlocks(xml: string, tag: string): string[] {
const re = new RegExp(`<${tag}>[\\s\\S]*?</${tag}>`, "gi");
return xml.match(re) || [];
}
function parseOneArticle(block: string): ArticleMetadata {
const pmid = extractTag(block, "PMID");
const title = stripTags(extractTag(block, "ArticleTitle"));
// Abstract can have multiple AbstractText sections
const abstractTexts = extractAllTags(block, "AbstractText");
const abstract = abstractTexts.map(stripTags).join("\n\n") || stripTags(extractTag(block, "AbstractText"));
// Authors
const authorBlocks = extractAllBlocks(block, "Author");
const authors = authorBlocks.map((a) => {
const last = stripTags(extractTag(a, "LastName"));
const fore = stripTags(extractTag(a, "ForeName"));
return [fore, last].filter(Boolean).join(" ");
}).filter(Boolean);
// Journal
const journal = stripTags(extractTag(block, "Title"));
// Publication date
const pubDateBlock = block.match(/<PubDate>[\s\S]*?<\/PubDate>/)?.[0] || "";
const year = extractTag(pubDateBlock, "Year");
const month = extractTag(pubDateBlock, "Month");
const day = extractTag(pubDateBlock, "Day");
const pubDate = [year, month, day].filter(Boolean).join(" ");
// DOI
const doiMatch = block.match(/<ArticleId IdType="doi">([^<]+)<\/ArticleId>/);
const doi = doiMatch ? doiMatch[1] : "";
// MeSH terms
const meshBlocks = extractAllBlocks(block, "MeshHeading");
const meshTerms = meshBlocks.map((m) => stripTags(extractTag(m, "DescriptorName"))).filter(Boolean);
return { pmid, title, abstract, authors, journal, pubDate, doi, meshTerms };
}
