OPML Reference

OPML (Outline Processor Markup Language) is a format for exchanging outline-structured information, commonly used for sharing feed subscription lists.

Versions	1.0, 2.0

Functions

parseOpml()

Parses OPML content and returns a typed OPML object.

import { parseOpml } from 'feedsmith'

const opml = parseOpml(xmlContent, {
  extraOutlineAttributes: ['customIcon', 'updateInterval']
})
// Returns: object with all fields optional and dates as strings

// Limit number of outlines parsed
const opml = parseOpml(xmlContent, { maxItems: 5 })

// Combine both options
const opml = parseOpml(xmlContent, {
  maxItems: 5,
  extraOutlineAttributes: ['customIcon', 'updateInterval']
})

Parameters

Parameter	Type	Description
content	string	The OPML XML content to parse
options	object	Optional parsing settings

Options

Option	Type	Default	Description
maxItems	number	-	Limit the number of outlines parsed. Use 0 to skip outlines entirely, useful when only OPML metadata is needed
extraOutlineAttributes	string[]	-	Custom attributes to extract from outline elements (case-insensitive), see examples

Returns

object - Parsed OPML with all fields optional and dates as strings

generateOpml()

Generates OPML XML from OPML data.

import { generateOpml } from 'feedsmith'

const xml = generateOpml(opmlData, {
  lenient: true,
  stylesheets: [{ type: 'text/xsl', href: '/opml.xsl' }],
  extraOutlineAttributes: ['customIcon', 'updateInterval']
})

Parameters

Parameter	Type	Description
data	object	OPML data to generate
options	object	Optional generation settings

Options

Option	Type	Default	Description
lenient	boolean	false	Enable lenient mode for relaxed validation, see Lenient Mode
stylesheets	Stylesheet[]	-	Add stylesheets for visual formatting, see Feed Styling
extraOutlineAttributes	string[]	-	Custom attributes to include in outline elements. Only specified attributes are included in generated XML, see examples

Returns

string - Generated OPML XML

Types

All OPML types are available under the Opml namespace:

import type { Opml } from 'feedsmith/types'

// Access any type from the definitions below
type Document = Opml.Document<Date>
type Head = Opml.Head<Date>
type Body = Opml.Body<Date>
type Outline = Opml.Outline<Date>
// … see type definitions below for all available types

See the TypeScript guide for usage examples.

Type Definitions

INFO

TDate represents date fields in the type definitions. When parsing, dates are returned as strings in their original format (see Parsing › Handling Dates for more details). When generating, dates should be provided as JavaScript Date objects.

export namespace Opml {
  export type Outline<
    TDate extends DateLike,
    A extends ReadonlyArray<string> = ReadonlyArray<string>,
  > = {
    text: string
    type?: string
    isComment?: boolean
    isBreakpoint?: boolean
    created?: TDate
    category?: string
    description?: string
    xmlUrl?: string
    htmlUrl?: string
    language?: string
    title?: string
    version?: string
    url?: string
    outlines?: Array<Outline<TDate, A>>
  } & ExtraFields<A>

  export type Head<TDate extends DateLike> = {
    title?: string
    dateCreated?: TDate
    dateModified?: TDate
    ownerName?: string
    ownerEmail?: string
    ownerId?: string
    docs?: string
    expansionState?: Array<number>
    vertScrollState?: number
    windowTop?: number
    windowLeft?: number
    windowBottom?: number
    windowRight?: number
  }

  export type Body<
    TDate extends DateLike,
    A extends ReadonlyArray<string> = ReadonlyArray<string>,
  > = {
    outlines?: Array<Outline<TDate, A>>
  }

  export type Document<
    TDate extends DateLike,
    A extends ReadonlyArray<string> = ReadonlyArray<string>,
  > = {
    head?: Head<TDate>
    body?: Body<TDate, A>
  }
}

INFO

The Outline type includes an index signature [key: string]: unknown which allows storing any custom attributes alongside the standard OPML properties.