Parsing Feeds

Feedsmith provides powerful parsing capabilities for various feed formats. The library offers both a universal parser that automatically detects feed formats and dedicated parsers for when you know the format in advance.

Universal Feed Parser

The simplest way to parse any feed is to use the universal parseFeed function:

import { parseFeed } from 'feedsmith'

const content = `
  <?xml version="1.0"?>
  <rss version="2.0">
    <channel>
      <title>My Blog</title>
      <description>A blog about web development</description>
      <link>https://example.com</link>
      <item>
        <title>Getting Started with Feedsmith</title>
        <description>Learn how to parse and generate feeds</description>
        <link>https://example.com/posts/feedsmith-intro</link>
        <pubDate>Mon, 15 Jan 2024 12:00:00 GMT</pubDate>
      </item>
    </channel>
  </rss>
`

const result = parseFeed(content)
result.format // rss
result.feed.title // My Blog
result.feed.items?.length // 1
result.feed.items?.[0]?.title // Getting Started with Feedsmith

The universal parser:

• Automatically detects the feed format using format detection functions
• Returns an object with format and feed properties
• Supports RSS, Atom, RDF, and JSON Feed formats
• Throws an error for unrecognized or invalid feeds

IMPORTANT

The universal parser uses detection functions to identify the feed format. While these work well for most feeds, they might not perfectly detect all valid feeds, especially those with non-standard structures. If you know the feed format in advance, using a dedicated parser is more reliable. See more on the feed format detection.

Dedicated Feed Parsers

When you know the feed format beforehand, use format-specific parsers for better performance and reliability:

import {
  parseRssFeed,
  parseAtomFeed,
  parseRdfFeed,
  parseJsonFeed
} from 'feedsmith'

// Parse specific formats
const rssFeed = parseRssFeed(rssContent)
const atomFeed = parseAtomFeed(atomContent)
const rdfFeed = parseRdfFeed(rdfContent)
const jsonFeed = parseJsonFeed(jsonContent)

// Then read the TypeScript suggestions for the specific feed format
rssFeed.title
rssFeed.dc?.creator
rssFeed.dc?.date
rssFeed.sy?.updateBase
rssFeed.items?.[0]?.title

OPML Parser

OPML (Outline Processor Markup Language) files, commonly used for feed subscription lists, have their own parser:

import { parseOpml } from 'feedsmith'

const opml = parseOpml(opmlContent)

// Access OPML structure
opml.head?.title
opml.body?.outlines

Error Handling

If the feed is unrecognized or invalid, an Error will be thrown with a descriptive message.

import { parseFeed, parseJsonFeed } from 'feedsmith'

try {
  const universalFeed = parseFeed('<not-a-feed></not-a-feed>')
} catch (error) {
  // Error: Unrecognized feed format
}

try {
  const jsonFeed = parseJsonFeed('{}')
} catch (error) {
  // Error: Invalid feed format
}

Returned Values

The parsing functions return JavaScript objects representing the feed in its original structure.

For detailed examples of input and output for each feed format, see the Parsing Examples page.