https://github.com/flevi29/oai_pmh_v2

Deno and Node.js API module for OAI-PMH.
https://github.com/flevi29/oai_pmh_v2

deno harvest javascript metadata nodejs oai-pmh protocol typescript

Last synced: 26 days ago
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Deno and Node.js API module for OAI-PMH.

• Host: GitHub
• URL: https://github.com/flevi29/oai_pmh_v2
• Owner: flevi29
• License: mit
• Created: 2022-08-25T09:48:26.000Z (about 2 years ago)
• Default Branch: main
• Last Pushed: 2024-06-13T11:46:34.000Z (5 months ago)
• Last Synced: 2024-09-30T20:05:29.280Z (about 1 month ago)
• Topics: deno, harvest, javascript, metadata, nodejs, oai-pmh, protocol, typescript
• Language: TypeScript
• Homepage:
• Size: 704 KB
• Stars: 4
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# OAI-PMH TypeScript client

[![Version][npm-svg]][npm-url]

It's an

[OAI-PMH Version 2.0](https://www.openarchives.org/OAI/openarchivesprotocol.html)

API client package/module for Node.js and Deno.

## Installing (Node.js)

```sh

npm i oai_pmh_v2

```

> [!IMPORTANT]

> For Node.js users a

> [`fetch`](https://developer.mozilla.org/en-US/docs/Web/API/fetch#browser_compatibility)

> compatible version of the runtime is required, or a polyfill otherwise (like

> [`node-fetch`](https://github.com/node-fetch/node-fetch?tab=readme-ov-file#providing-global-access)).

## Example

> [!NOTE]

> It is possible to iterate through the generator with a `for...of`

> loop, but this way we can only acquire the

> [`yield`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/yield)

> -ed values of the generator, the `return` -ed value would be lost, and the

> `return` -ed value contains the potential error.

```typescript

// `... from "npm:oai_pmh_v2"` for Deno

import { OAIPMH, STATUS } from "oai_pmh_v2";

// 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",

});

const g = oaiPMH.listIdentifiers(

  { metadataPrefix: "marc21", from: "2015-04-10", until: "2015-10-28" },

  { signal: AbortSignal.timeout(30_000) },

);

for (;;) {

  const { done, value: gVal } = await g.next();

  if (done) {

    // there are no more values yielded by the generator

    const { status, value } = gVal;

    if (status !== STATUS.OK) {

      // handle error, we can narrow error type by checking

      // against specific values of `STATUS` enum

      console.error(value);

    }

    // break out of loop as there are no more yielded values

    break;

  }

  console.log(JSON.stringify(gVal));

}

```

> [!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](https://github.com/nodejs/undici/issues/939).

## General shape of parsed data

```typescript

type ParsedXMLRecordValue = {

  // index in XML tree branch, for preserving order of elements

  i: number;

  // XML attributes

  attr?: Record;

  // 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;

```

Find examples for all methods in

[examples directory](https://github.com/flevi29/oai_pmh_v2/tree/main/examples).

Documentation via types.

[npm-svg]: https://img.shields.io/npm/v/oai_pmh_v2.svg?style=flat-square

[npm-url]: https://npmjs.org/package/oai_pmh_v2