@extremesolution/podcast-feed-parser

A highly customizable package for fetching and parsing podcast feeds into simple and manageable JavaScript objects. For use with node and in the browser.


Keywords
javascript, podcast, podcast-client, podcast-fetcher, podcast-aggregator, rss, parse, parser, feed, node, podcast-downloader
License
ISC
Install
npm install @extremesolution/podcast-feed-parser@1.0.4

Documentation

npm version Build Status

NPM

Table of Contents

podcast-feed-parser

A highly customizable package for fetching and parsing podcast feeds into simple and manageable JavaScript objects. For use with node and in the browser.

Overview

By default, podcast-feed-parser will parse a podcast's xml feed and return an object with the following properties. meta contains all of the information pertinent to the podcast show itself, and episodes is list of episode objects which contain the information pertinent to each individual episode of the podcast.

{
    meta: {
      title: 'My podcast',
      description: 'A podcast about whatever',
      // ...
    },
    episodes: [
      {
        title: 'My Episode 1',
        description: 'Episode 1',
        pubDate: '2018-11-29T10:30:00.000Z',
        // ...
      }, {
        title: 'My Episode 2',
        description: 'Episode 2',
        pubDate: '2018-11-28T10:30:00.000Z',
        // ...
      }
    ]
  }
}

Quickstart

podcast-feed-parser has two main functions: getPodcastFromFeed and getPodcastFromURL.

For fetching remote feeds from urls, use getPodcastFromURL:

const podcastFeedParser = require("podcast-feed-parser")

// for fetching remote feeds, use getPodcastFromURL.
// Note that function must be async
async function printPodcastTitle (url) {
	const podcast = await podcastFeedParser.getPodcastFromURL(url)
	console.log(podcast.meta.title)
}

printPodcastTitle('http://feeds.gimletmedia.com/hearreplyall')
// "Reply All"

If you already have the podcast feed xml, use getPodcastFromFeed:

const podcastFeedParser = require("podcast-feed-parser")
const fs = require('fs')

// if you already have the feed xml, you can parse
// synchronously with getPodcastFromFeed
const podcastFeed = fs.readFileSync('path/to/podcast-feed.xml', 'utf8')
const podcast = podcastFeedParser.getPodcastFromFeed(podcastFeed)

console.log(podcast.meta.title)
// "My Podcast"

podcast.episodes.forEach( (episode) => {
	console.log(episode.title)
})
// "My Episode 1"
// "My Episode 2"

Default

By default, podcast-feed-parser will parse a feed for the following default fields, based on this standard. If a field is not found in a feed, it will quietly return undefined.

{
    meta: {
        title: '',
        description: '',
        subtitle: '',
        imageURL: '',
        lastUpdated: '',
        link: '',
        language: '',
        editor: '',
        author: '',
        summary: '',
        categories: [],
        owner: {
            name: '',
            email: ''
        },
        explicit: true,
        complete: true,
        blocked: true
    },
    episodes: [
      {
        title: '',
        description: '',
        imageURL: '',
        pubDate: '',
        link: '',
        language: '',
        enclosure: {
            length: '0',
            type: '',
            url: ''
        },
        duration: 0,
        summary: '',
        blocked: true,
        explicit: true,
        order: 1
      }
  ]
}

Configuration

You can customize podcast-feed-parser by passing an optional options object to either of parsing functions, getPodcastFromFeed and getPodcastFromURL. The options object consists of three components: fields, required, and uncleaned.

const options = {
  // specifies the fields to be parsed from the podcast feed
  fields: {
    meta: [],
    episodes: []
  },
  // specifies the fields which must be present for the function to return without
  // an error
  required: {
    meta: [],
    episodes: []
  },
  // specifies which fields should not have any of the cleaning functions applied
  uncleaned: {
    meta: [],
    episodes: []
  }
}

Fields

If no options object is passed to the parsing function, or if no fields are specified, then the fields listed in the Default section are applied.

Specifying particular fields

If you specify particular fields for either meta or episodes, the final podcast object will only consist of those fields.

const options = {
  fields : {
    'meta': ['title', 'description', 'webMaster'],
    'episodes': ['title', 'pubDate', 'timeline']
  }
}

const podcast = podcastFeedParser.getPodcastFromFeed(sampleFeed, options)

console.log(podcast)
// { meta:
//    { title: 'All Things Chemical',
//      description: 'All Things Chemical is a podcast...',
//      webMaster: 'Jackson Bierfeldt (jbierfeldt@gmail.com)'
//    },
//   episodes:
//     [ { title: 'Confidential Business Information under TSCA',
//        pubDate: '2018-11-29T10:30:00.000Z',
//        timeline: 'http://timelinenotation.com/pages/documentation/notation.php' }
//     ] }
// }

Extending default fields

If you wish to use the default fields listed in the Default section, but to also parse an additional field, you can include 'default' in the list of desired fields, along with the names of the additional fields you wish to parse.

const options = {
  fields : {
    'meta': ['default', 'webMaster'],
    'episodes': ['default', 'timeline']
  }
}

const podcast = podcastFeedParser.getPodcastFromFeed(sampleFeed, options)

console.log(podcast)
// { meta:
//    { title: 'All Things Chemical',
//      description: 'All Things Chemical is a podcast...',
//      subtitle: 'A Podcast...',
//      ...
//      [all default meta fields]
//      ...
//      webMaster: 'Jackson Bierfeldt (jbierfeldt@gmail.com)'
//    },
//   episodes:
//     [ { title: 'Confidential Business Information under TSCA',
//        ...
//        [all default episode fields]
//        ...
//        timeline: 'http://timelinenotation.com/pages/documentation/notation.php' }
//     ] }
// }

Required

By default, podcast-feed-parser will quietly return an undefined value if it tries to parse a field in a podcast feed that does not exist. If you wish for the function to halt and throw requiredError when a particular field is missing, you can specify those fields in the required options object.

const options = {
  fields : {
    'meta': ['title', 'description'],
    'episodes': ['title', 'pubDate']
  },
  required: {
    'meta': ['title']
  }
}

const podcast = podcastFeedParser.getPodcastFromFeed(sampleFeed, options)

// If podcast feed does not have a title attribute, parser will throw a requiredError

// If podcast feed does not have a description attribute, parsing will continue
// and the resulting podcast object will have an undefined attribute for meta.description

Uncleaned

By default, podcast-feed-parser will clean and standardize the data for several fields. For example, the podcast object returned by podcast-feed-parser will always return durations as integer numbers of seconds, not as formatted strings. This is for convenience when working with many different unstandardized podcast feeds from different sources.

A full list of the fields which are cleaned and the functions used to clean them can be found in the CLEAN FUNCTIONS section of index.js.

If you would like the data in the podcast object to resemble exactly that of the podcast feed, you can list fields which should remain uncleaned in the uncleaned options object. These fields will have no cleaning applied to them after parsing.

// sampleFeed
<xml>
  <itunes:duration>39:58</itunes:duration>
</xml>

// -------------

// default behavior with no options supplied
const podcast = podcastFeedParser.getPodcastFromFeed(sampleFeed)
console.log(podcast.episodes[0].duration)
// 2398

// -------------

const options = {
  uncleaned: {
    'episodes': ['duration']
  }
}

const podcast = podcastFeedParser.getPodcastFromFeed(sampleFeed, options)
console.log(podcast.episodes[0].duration)
// ['39:58']

Asynchronously Fetching Remote Feeds

podcast-feed-parser can also fetch and parse remote feeds in both the browser and server environment thanks to isomorphic-fetch. Simply call getPodcastFromURL(url, options). Functions which fetch remote feeds must be asynchronous and utilize async/await.

const podcastFeedParser = require("podcast-feed-parser")

async function getNumberOfEpisodes (url) {
	const podcast = await podcastFeedParser.getPodcastFromURL(url)
	console.log(podcast.meta.title, podcast.episodes.length)
}

getNumberOfEpisodes('http://feeds.gimletmedia.com/hearreplyall')
// "Reply All"
// 148

Errors

podcast-feed-parser has a variety of custom errors. These are exposed under exports.ERRORS and are as follows:

exports.ERRORS = {
  'parsingError' : new Error("Parsing error."),
  'requiredError' : new Error("One or more required values are missing from feed."),
  'fetchingError' : new Error("Fetching error."),
  'optionsError' : new Error("Invalid options.")
}