@extractus/feed-extractor

feed-extractor

To read & normalize RSS/ATOM/JSON feed data.

(This library is derived from feed-reader renamed.)

Demo

• Give it a try!
• Example FaaS

Install & Usage

Node.js

npm i @extractus/feed-extractor

import { extract } from '@extractus/feed-extractor'

// extract a RSS
const result = await extract('https://news.google.com/rss')
console.log(result)

Deno

// deno < 1.28
import { extract } from 'https://esm.sh/@extractus/feed-extractor'

// deno > 1.28
import { extract } from 'npm:@extractus/feed-extractor'

Browser

import { extract } from 'https://esm.sh/@extractus/feed-extractor'

Please check the examples for reference.

APIs

• extract()
• extractFromJson()
• extractFromXml()

Note:

• Old method read() has been marked as deprecated and will be removed in next major release.

---

extract()

Load and extract feed data from given RSS/ATOM/JSON source. Return a Promise object.

Syntax

extract(String url)
extract(String url, Object parserOptions)
extract(String url, Object parserOptions, Object fetchOptions)

Example:

import { extract } from '@extractus/feed-extractor'

const result = await extract('https://news.google.com/atom')
console.log(result)

Without any options, the result should have the following structure:

{
  title: String,
  link: String,
  description: String,
  generator: String,
  language: String,
  published: ISO Date String,
  entries: Array[
    {
      id: String,
      title: String,
      link: String,
      description: String,
      published: ISO Datetime String
    },
    // ...
  ]
}

Parameters

url required

URL of a valid feed source

Feed content must be accessible and conform one of the following standards:

• RSS Feed
• ATOM Feed
• JSON Feed

parserOptions optional

Object with all or several of the following properties:

• normalization: Boolean, normalize feed data or keep original. Default true.
• useISODateFormat: Boolean, convert datetime to ISO format. Default true.
• descriptionMaxLen: Number, to truncate description. Default 250 characters. Set to 0 = no truncation.
• xmlParserOptions: Object, used by xml parser, view fast-xml-parser's docs
• getExtraFeedFields: Function, to get more fields from feed data
• getExtraEntryFields: Function, to get more fields from feed entry data
• baseUrl: URL string, to absolutify the links within feed content

For example:

import { extract } from '@extractus/feed-extractor'

await extract('https://news.google.com/atom', {
  useISODateFormat: false
})

await extract('https://news.google.com/rss', {
  useISODateFormat: false,
  getExtraFeedFields: (feedData) => {
    return {
      subtitle: feedData.subtitle || ''
    }
  },
  getExtraEntryFields: (feedEntry) => {
    const {
      enclosure,
      category
    } = feedEntry
    return {
      enclosure: {
        url: enclosure['@_url'],
        type: enclosure['@_type'],
        length: enclosure['@_length']
      },
      category: isString(category) ? category : {
        text: category['@_text'],
        domain: category['@_domain']
      }
    }
  }
})

fetchOptions optional

fetchOptions is an object that can have the following properties:

• headers: to set request headers
• proxy: another endpoint to forward the request to
• agent: a HTTP proxy agent
• signal: AbortController signal or AbortSignal timeout to terminate the request

For example, you can use this param to set request headers to fetch as below:

import { extract } from '@extractus/feed-extractor'

const url = 'https://news.google.com/rss'
await extract(url, null, {
  headers: {
    'user-agent': 'Opera/9.60 (Windows NT 6.0; U; en) Presto/2.1.1'
  }
})

You can also specify a proxy endpoint to load remote content, instead of fetching directly.

For example:

import { extract } from '@extractus/feed-extractor'

const url = 'https://news.google.com/rss'

await extract(url, null, {
  headers: {
    'user-agent': 'Opera/9.60 (Windows NT 6.0; U; en) Presto/2.1.1'
  },
  proxy: {
    target: 'https://your-secret-proxy.io/loadXml?url=',
    headers: {
      'Proxy-Authorization': 'Bearer YWxhZGRpbjpvcGVuc2VzYW1l...'
    }
  }
})

Passing requests to proxy is useful while running @extractus/feed-extractor on browser. View examples/browser-feed-reader as reference example.

Another way to work with proxy is use agent option instead of proxy as below:

import { extract } from '@extractus/feed-extractor'

import { HttpsProxyAgent } from 'https-proxy-agent'

const proxy = 'http://abc:[e-mail]:31113'

const url = 'https://news.google.com/rss'

const feed = await extract(url, null, {
  agent: new HttpsProxyAgent(proxy),
})
console.log('Run feed-extractor with proxy:', proxy)
console.log(feed)

For more info about https-proxy-agent, check its repo.

By default, there is no request timeout. You can use the option signal to cancel request at the right time.

The common way is to use AbortControler:

const controller = new AbortController()

// stop after 5 seconds
setTimeout(() => {
  controller.abort()
}, 5000)

const data = await extract(url, null, {
  signal: controller.signal,
})

A newer solution is AbortSignal's timeout() static method:

// stop after 5 seconds
const data = await extract(url, null, {
  signal: AbortSignal.timeout(5000),
})

For more info:

• AbortController constructor
• AbortSignal: timeout() static method

extractFromJson()

Extract feed data from JSON string. Return an object which contains feed data.

Syntax

extractFromJson(String json)
extractFromJson(String json, Object parserOptions)

Example:

import { extractFromJson } from '@extractus/feed-extractor'

const url = 'https://www.jsonfeed.org/feed.json'
// this resource provides data in JSON feed format
// so we fetch remote content as json
// then pass to feed-extractor
const res = await fetch(url)
const json = await res.json()

const feed = extractFromJson(json)
console.log(feed)

Parameters

json required

JSON string loaded from JSON feed resource.

parserOptions optional

See parserOptions above.

extractFromXml()

Extract feed data from XML string. Return an object which contains feed data.

Syntax

extractFromXml(String xml)
extractFromXml(String xml, Object parserOptions)

Example:

import { extractFromXml } from '@extractus/feed-extractor'

const url = 'https://news.google.com/atom'
// this resource provides data in ATOM feed format
// so we fetch remote content as text
// then pass to feed-extractor
const res = await fetch(url)
const xml = await res.text()

const feed = extractFromXml(xml)
console.log(feed)

Parameters

xml required

XML string loaded from RSS/ATOM feed resource.

parserOptions optional

See parserOptions above.

Test

git clone https://github.com/extractus/feed-extractor.git
cd feed-extractor
pnpm i
pnpm test

Quick evaluation

git clone https://github.com/extractus/feed-extractor.git
cd feed-extractor
pnpm i
pnpm eval https://news.google.com/rss

License

The MIT License (MIT)

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