OAI-PMH TypeScript client
It's an OAI-PMH Version 2.0 API client package/module for Node.js and Deno.
Installing (Node.js)
npm i oai_pmh_v2
[!IMPORTANT] For Node.js users, minimum 18.0.0 is required, and this is an ESM only package, read more here and maybe here.
Example
// Node.js
import { OAIPMH, OAIPMHError, ParsedOAIPMHError } from "oai_pmh_v2";
// Deno
import {
OAIPMH,
OAIPMHError,
ParsedOAIPMHError,
} from "https://deno.land/x/oai_pmh_v2/src/mod.ts";
// you can find OAI-PMH providers here (although a lot of them might not work):
// https://www.openarchives.org/Register/BrowseSites
const oaiPMH = new OAIPMH({
baseUrl:
"http://bibliotecavirtual.asturias.es/i18n/oai/oai_bibliotecavirtual.asturias.es.cmd",
});
try {
for await (
const values of oaiPMH.listIdentifiers(
{ metadataPrefix: "marc21", from: "2015-08-03", until: "2016-05-30" },
{ signal: AbortSignal.timeout(20_000) },
)
) {
console.log(JSON.stringify(values));
}
const info = await oaiPMH.identify();
console.log(info);
} catch (error: unknown) {
console.error(error);
if (
error instanceof OAIPMHError && error.cause instanceof ParsedOAIPMHError
) {
// this means there are specific errors returned by the OAI-PMH provider
for (const returnedError of error.cause.cause) {
console.error(returnedError);
}
}
}
[!WARNING] When using an
AbortSignal
with any list method (listIdentifiers
,listRecords
,listSets
), there will be some minuscule memory leak until the loop exits. This is because for each request there is an additional listener registered for the signal. Specifically in Node.js this will cause a lot of warnings (after 100 or so loops). This is a fetch API spec limitation, see issue.
General shape of parsed data
type ParsedXMLRecordValue = {
// index in XML tree branch, for preserving order of elements
i: number;
// XML attributes
attr?: Record<string, string>;
// either a text value, another branch of the XML tree,
// or undefined in case of an empty XML element
val?: string | ParsedXML;
};
type ParsedXML = Record<string, ParsedXMLRecordValue[]>;
Find examples for all methods in examples directory. Documentation via types.