feeds

README

gorilla/feeds

feeds is a web feed generator library for generating RSS, Atom and JSON feeds from Go applications.

This is a fork of the original gorilla/feeds library.

Documentation

Overview

Syndication (feed) generator library for golang.

Installing

go get github.com/jlelse/feeds

Feeds provides a simple, generic Feed interface with a generic Item object as well as RSS, Atom and JSON Feed specific RssFeed, AtomFeed and JSONFeed objects which allow access to all of each spec's defined elements.

Examples

Create a Feed and some Items in that feed using the generic interfaces:

import (
	"time"
	. "github.com/jlelse/feeds"
)

now = time.Now()

feed := &Feed{
	Title:       "jmoiron.net blog",
	Link:        &Link{Href: "http://jmoiron.net/blog"},
	Description: "discussion about tech, footie, photos",
	Author:      &Author{Name: "Jason Moiron", Email: "jmoiron@jmoiron.net"},
	Created:     now,
	Copyright:   "This work is copyright © Benjamin Button",
}

feed.Items = []*Item{
	&Item{
		Title:       "Limiting Concurrency in Go",
		Link:        &Link{Href: "http://jmoiron.net/blog/limiting-concurrency-in-go/"},
		Description: "A discussion on controlled parallelism in golang",
		Author:      &Author{Name: "Jason Moiron", Email: "jmoiron@jmoiron.net"},
		Created:     now,
	},
	&Item{
		Title:       "Logic-less Template Redux",
		Link:        &Link{Href: "http://jmoiron.net/blog/logicless-template-redux/"},
		Description: "More thoughts on logicless templates",
		Created:     now,
	},
	&Item{
		Title:       "Idiomatic Code Reuse in Go",
		Link:        &Link{Href: "http://jmoiron.net/blog/idiomatic-code-reuse-in-go/"},
		Description: "How to use interfaces <em>effectively</em>",
		Created:     now,
	},
}

From here, you can output Atom, RSS, or JSON Feed versions of this feed easily

atom, err := feed.ToAtom()
rss, err := feed.ToRss()
json, err := feed.ToJSON()

You can also get access to the underlying objects that feeds uses to export its XML

atomFeed := (&Atom{Feed: feed}).AtomFeed()
rssFeed := (&Rss{Feed: feed}).RssFeed()
jsonFeed := (&JSON{Feed: feed}).JSONFeed()

From here, you can modify or add each syndication's specific fields before outputting

atomFeed.Subtitle = "plays the blues"
atom, err := ToXML(atomFeed)
rssFeed.Generator = "gorilla/feeds v1.0 (github.com/jlelse/feeds)"
rss, err := ToXML(rssFeed)
jsonFeed.NextUrl = "https://www.example.com/feed.json?page=2"
json, err := jsonFeed.ToJSON()

Index

• func ToXML(feed XmlFeed) (string, error)
• func WriteXML(feed XmlFeed, w io.Writer) error
• type Atom
  • func (a *Atom) AtomFeed() *AtomFeed
  • func (a *Atom) FeedXml() interface{}
• type AtomAuthor
• type AtomContent
• type AtomContributor
• type AtomEntry
• type AtomFeed
  • func (a *AtomFeed) FeedXml() interface{}
• type AtomLink
• type AtomPerson
• type AtomSummary
• type Author
• type Enclosure
• type Feed
  • func (f *Feed) Add(item *Item)
  • func (f *Feed) Sort(less func(a, b *Item) bool)
  • func (f *Feed) ToAtom() (string, error)
  • func (f *Feed) ToJSON() (string, error)
  • func (f *Feed) ToRss() (string, error)
  • func (f *Feed) WriteAtom(w io.Writer) error
  • func (f *Feed) WriteJSON(w io.Writer) error
  • func (f *Feed) WriteRss(w io.Writer) error
• type Image
• type Item
• type JSON
  • func (f *JSON) JSONFeed() *JSONFeed
  • func (f *JSON) ToJSON() (string, error)
• type JSONAttachment
  • func (a *JSONAttachment) MarshalJSON() ([]byte, error)
  • func (a *JSONAttachment) UnmarshalJSON(data []byte) error
• type JSONAuthor
• type JSONFeed
  • func (f *JSONFeed) ToJSON() (string, error)
• type JSONHub
• type JSONItem
• type Link
• type Rss
  • func (r *Rss) FeedXml() interface{}
  • func (r *Rss) RssFeed() *RssFeed
• type RssContent
• type RssEnclosure
• type RssFeed
  • func (r *RssFeed) FeedXml() interface{}
• type RssFeedXml
• type RssImage
• type RssItem
• type RssTextInput
• type XmlFeed

Functions

func ToXML

func ToXML(feed XmlFeed) (string, error)

turn a feed object (either a Feed, AtomFeed, or RssFeed) into xml returns an error if xml marshaling fails

func WriteXML

func WriteXML(feed XmlFeed, w io.Writer) error

WriteXML writes a feed object (either a Feed, AtomFeed, or RssFeed) as XML into the writer. Returns an error if XML marshaling fails.

Types

type Atom

type Atom struct {
	*Feed
}

func (*Atom) AtomFeed

func (a *Atom) AtomFeed() *AtomFeed

create a new AtomFeed with a generic Feed struct's data

func (*Atom) FeedXml

func (a *Atom) FeedXml() interface{}

FeedXml returns an XML-Ready object for an Atom object

type AtomAuthor

type AtomAuthor struct {
	XMLName xml.Name `xml:"author"`
	AtomPerson
}

type AtomContent

type AtomContent struct {
	XMLName xml.Name `xml:"content"`
	Content string   `xml:",chardata"`
	Type    string   `xml:"type,attr"`
}

type AtomContributor

type AtomContributor struct {
	XMLName xml.Name `xml:"contributor"`
	AtomPerson
}

type AtomEntry

type AtomEntry struct {
	XMLName     xml.Name `xml:"entry"`
	Xmlns       string   `xml:"xmlns,attr,omitempty"`
	Title       string   `xml:"title"`   // required
	Updated     string   `xml:"updated"` // required
	Id          string   `xml:"id"`      // required
	Category    string   `xml:"category,omitempty"`
	Content     *AtomContent
	Rights      string `xml:"rights,omitempty"`
	Source      string `xml:"source,omitempty"`
	Published   string `xml:"published,omitempty"`
	Contributor *AtomContributor
	Links       []AtomLink   // required if no child 'content' elements
	Summary     *AtomSummary // required if content has src or content is base64
	Author      *AtomAuthor  // required if feed lacks an author
}

type AtomFeed

type AtomFeed struct {
	XMLName     xml.Name `xml:"feed"`
	Xmlns       string   `xml:"xmlns,attr"`
	Title       string   `xml:"title"`   // required
	Id          string   `xml:"id"`      // required
	Updated     string   `xml:"updated"` // required
	Category    string   `xml:"category,omitempty"`
	Icon        string   `xml:"icon,omitempty"`
	Logo        string   `xml:"logo,omitempty"`
	Rights      string   `xml:"rights,omitempty"` // copyright used
	Subtitle    string   `xml:"subtitle,omitempty"`
	Link        *AtomLink
	Author      *AtomAuthor `xml:"author,omitempty"`
	Contributor *AtomContributor
	Entries     []*AtomEntry `xml:"entry"`
}

func (*AtomFeed) FeedXml

func (a *AtomFeed) FeedXml() interface{}

FeedXml returns an XML-ready object for an AtomFeed object

type AtomLink

type AtomLink struct {
	//Atom 1.0 <link rel="enclosure" type="audio/mpeg" title="MP3" href="http://www.example.org/myaudiofile.mp3" length="1234" />
	XMLName xml.Name `xml:"link"`
	Href    string   `xml:"href,attr"`
	Rel     string   `xml:"rel,attr,omitempty"`
	Type    string   `xml:"type,attr,omitempty"`
	Length  string   `xml:"length,attr,omitempty"`
}

Multiple links with different rel can coexist

type AtomPerson

type AtomPerson struct {
	Name  string `xml:"name,omitempty"`
	Uri   string `xml:"uri,omitempty"`
	Email string `xml:"email,omitempty"`
}

type AtomSummary

type AtomSummary struct {
	XMLName xml.Name `xml:"summary"`
	Content string   `xml:",chardata"`
	Type    string   `xml:"type,attr"`
}

type Author

type Author struct {
	Name, Email string
}

type Enclosure

type Enclosure struct {
	Url, Length, Type string
}

type Feed

type Feed struct {
	Title       string
	Link        *Link
	Description string
	Author      *Author
	Updated     time.Time
	Created     time.Time
	Id          string
	Subtitle    string
	Items       []*Item
	Copyright   string
	Image       *Image
	Language    string
}

func (*Feed) Add

func (f *Feed) Add(item *Item)

add a new Item to a Feed

func (*Feed) Sort

func (f *Feed) Sort(less func(a, b *Item) bool)

Sort sorts the Items in the feed with the given less function.

func (*Feed) ToAtom

func (f *Feed) ToAtom() (string, error)

creates an Atom representation of this feed

func (*Feed) ToJSON

func (f *Feed) ToJSON() (string, error)

ToJSON creates a JSON Feed representation of this feed

func (*Feed) ToRss

func (f *Feed) ToRss() (string, error)

creates an Rss representation of this feed

func (*Feed) WriteAtom

func (f *Feed) WriteAtom(w io.Writer) error

WriteAtom writes an Atom representation of this feed to the writer.

func (*Feed) WriteJSON

func (f *Feed) WriteJSON(w io.Writer) error

WriteJSON writes an JSON representation of this feed to the writer.

func (*Feed) WriteRss

func (f *Feed) WriteRss(w io.Writer) error

WriteRss writes an RSS representation of this feed to the writer.

type Image

type Image struct {
	Url, Title, Link string
	Width, Height    int
}

type Item

type Item struct {
	Title       string
	Link        *Link
	Source      *Link
	Author      *Author
	Description string // used as description in rss, summary in atom
	Id          string // used as guid in rss, id in atom
	Updated     time.Time
	Created     time.Time
	Enclosure   *Enclosure
	Content     string
}

type JSON

type JSON struct {
	*Feed
}

JSON is used to convert a generic Feed to a JSONFeed.

func (*JSON) JSONFeed

func (f *JSON) JSONFeed() *JSONFeed

JSONFeed creates a new JSONFeed with a generic Feed struct's data.

func (*JSON) ToJSON

func (f *JSON) ToJSON() (string, error)

ToJSON encodes f into a JSON string. Returns an error if marshalling fails.

type JSONAttachment

type JSONAttachment struct {
	Url      string        `json:"url,omitempty"`
	MIMEType string        `json:"mime_type,omitempty"`
	Title    string        `json:"title,omitempty"`
	Size     int           `json:"size_in_bytes,omitempty"`
	Duration time.Duration `json:"duration_in_seconds,omitempty"`
}

JSONAttachment represents a related resource. Podcasts, for instance, would include an attachment that’s an audio or video file.

func (*JSONAttachment) MarshalJSON

func (a *JSONAttachment) MarshalJSON() ([]byte, error)

MarshalJSON implements the json.Marshaler interface. The Duration field is marshaled in seconds, all other fields are marshaled based upon the definitions in struct tags.

func (*JSONAttachment) UnmarshalJSON

func (a *JSONAttachment) UnmarshalJSON(data []byte) error

UnmarshalJSON implements the json.Unmarshaler interface. The Duration field is expected to be in seconds, all other field types match the struct definition.

type JSONAuthor

type JSONAuthor struct {
	Name   string `json:"name,omitempty"`
	Url    string `json:"url,omitempty"`
	Avatar string `json:"avatar,omitempty"`
}

JSONAuthor represents the author of the feed or of an individual item in the feed

type JSONFeed

type JSONFeed struct {
	Version     string        `json:"version"`
	Title       string        `json:"title"`
	HomePageUrl string        `json:"home_page_url,omitempty"`
	FeedUrl     string        `json:"feed_url,omitempty"`
	Description string        `json:"description,omitempty"`
	UserComment string        `json:"user_comment,omitempty"`
	NextUrl     string        `json:"next_url,omitempty"`
	Icon        string        `json:"icon,omitempty"`
	Favicon     string        `json:"favicon,omitempty"`
	Author      *JSONAuthor   `json:"author,omitempty"` // Deprecated, keep for compatibility
	Authors     []*JSONAuthor `json:"authors,omitempty"`
	Language    string        `json:"language,omitempty"`
	Expired     bool          `json:"expired,omitempty"`
	Hubs        []*JSONHub    `json:"hubs,omitempty"`
	Items       []*JSONItem   `json:"items,omitempty"`
}

JSONFeed represents a syndication feed in the JSON Feed Version 1 format. Matching the specification found here: https://jsonfeed.org/version/1.

func (*JSONFeed) ToJSON

func (f *JSONFeed) ToJSON() (string, error)

ToJSON encodes f into a JSON string. Returns an error if marshalling fails.

type JSONHub

type JSONHub struct {
	Type string `json:"type"`
	Url  string `json:"url"`
}

JSONHub describes an endpoint that can be used to subscribe to real-time notifications from the publisher of this feed.

type JSONItem

type JSONItem struct {
	Id            string            `json:"id"`
	Url           string            `json:"url,omitempty"`
	ExternalUrl   string            `json:"external_url,omitempty"`
	Title         string            `json:"title,omitempty"`
	ContentHTML   string            `json:"content_html,omitempty"`
	ContentText   string            `json:"content_text,omitempty"`
	Summary       string            `json:"summary,omitempty"`
	Image         string            `json:"image,omitempty"`
	BannerImage   string            `json:"banner_,omitempty"`
	PublishedDate *time.Time        `json:"date_published,omitempty"`
	ModifiedDate  *time.Time        `json:"date_modified,omitempty"`
	Author        *JSONAuthor       `json:"author,omitempty"` // Deprecated, keep for compatibility
	Authors       []*JSONAuthor     `json:"authors,omitempty"`
	Tags          []string          `json:"tags,omitempty"`
	Language      string            `json:"language,omitempty"`
	Attachments   []*JSONAttachment `json:"attachments,omitempty"`
}

JSONItem represents a single entry/post for the feed.

type Link

type Link struct {
	Href, Rel, Type, Length string
}

type Rss

type Rss struct {
	*Feed
}

func (*Rss) FeedXml

func (r *Rss) FeedXml() interface{}

FeedXml returns an XML-Ready object for an Rss object

func (*Rss) RssFeed

func (r *Rss) RssFeed() *RssFeed

create a new RssFeed with a generic Feed struct's data

type RssContent

type RssContent struct {
	XMLName xml.Name `xml:"content:encoded"`
	Content string   `xml:",cdata"`
}

type RssEnclosure

type RssEnclosure struct {
	//RSS 2.0 <enclosure url="http://example.com/file.mp3" length="123456789" type="audio/mpeg" />
	XMLName xml.Name `xml:"enclosure"`
	Url     string   `xml:"url,attr"`
	Length  string   `xml:"length,attr"`
	Type    string   `xml:"type,attr"`
}

type RssFeed

type RssFeed struct {
	XMLName        xml.Name `xml:"channel"`
	Title          string   `xml:"title"`       // required
	Link           string   `xml:"link"`        // required
	Description    string   `xml:"description"` // required
	Language       string   `xml:"language,omitempty"`
	Copyright      string   `xml:"copyright,omitempty"`
	ManagingEditor string   `xml:"managingEditor,omitempty"` // Author used
	WebMaster      string   `xml:"webMaster,omitempty"`
	PubDate        string   `xml:"pubDate,omitempty"`       // created or updated
	LastBuildDate  string   `xml:"lastBuildDate,omitempty"` // updated used
	Category       string   `xml:"category,omitempty"`
	Generator      string   `xml:"generator,omitempty"`
	Docs           string   `xml:"docs,omitempty"`
	Cloud          string   `xml:"cloud,omitempty"`
	Ttl            int      `xml:"ttl,omitempty"`
	Rating         string   `xml:"rating,omitempty"`
	SkipHours      string   `xml:"skipHours,omitempty"`
	SkipDays       string   `xml:"skipDays,omitempty"`
	Image          *RssImage
	TextInput      *RssTextInput
	Items          []*RssItem `xml:"item"`
}

func (*RssFeed) FeedXml

func (r *RssFeed) FeedXml() interface{}

FeedXml returns an XML-ready object for an RssFeed object

type RssFeedXml

type RssFeedXml struct {
	XMLName          xml.Name `xml:"rss"`
	Version          string   `xml:"version,attr"`
	ContentNamespace string   `xml:"xmlns:content,attr"`
	Channel          *RssFeed
}

private wrapper around the RssFeed which gives us the <rss>..</rss> xml

type RssImage

type RssImage struct {
	XMLName xml.Name `xml:"image"`
	Url     string   `xml:"url"`
	Title   string   `xml:"title"`
	Link    string   `xml:"link"`
	Width   int      `xml:"width,omitempty"`
	Height  int      `xml:"height,omitempty"`
}

type RssItem

type RssItem struct {
	XMLName     xml.Name `xml:"item"`
	Title       string   `xml:"title"`       // required
	Link        string   `xml:"link"`        // required
	Description string   `xml:"description"` // required
	Content     *RssContent
	Author      string `xml:"author,omitempty"`
	Category    string `xml:"category,omitempty"`
	Comments    string `xml:"comments,omitempty"`
	Enclosure   *RssEnclosure
	Guid        string `xml:"guid,omitempty"`    // Id used
	PubDate     string `xml:"pubDate,omitempty"` // created or updated
	Source      string `xml:"source,omitempty"`
}

type RssTextInput

type RssTextInput struct {
	XMLName     xml.Name `xml:"textInput"`
	Title       string   `xml:"title"`
	Description string   `xml:"description"`
	Name        string   `xml:"name"`
	Link        string   `xml:"link"`
}

type XmlFeed

type XmlFeed interface {
	FeedXml() interface{}
}

interface used by ToXML to get a object suitable for exporting XML.