Add RSS/Atom feed support for user actions (#16002)

Return rss/atom feed for user based on rss url suffix or Content-Type header.

vendor/github.com/gorilla/feeds/rss.go

@@ -0,0 +1,168 @@
+package feeds
+
+// rss support
+// validation done according to spec here:
+//    http://cyber.law.harvard.edu/rss/rss.html
+
+import (
+	"encoding/xml"
+	"fmt"
+	"time"
+)
+
+// private wrapper around the RssFeed which gives us the <rss>..</rss> xml
+type RssFeedXml struct {
+	XMLName          xml.Name `xml:"rss"`
+	Version          string   `xml:"version,attr"`
+	ContentNamespace string   `xml:"xmlns:content,attr"`
+	Channel          *RssFeed
+}
+
+type RssContent struct {
+	XMLName xml.Name `xml:"content:encoded"`
+	Content string   `xml:",cdata"`
+}
+
+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 RssTextInput struct {
+	XMLName     xml.Name `xml:"textInput"`
+	Title       string   `xml:"title"`
+	Description string   `xml:"description"`
+	Name        string   `xml:"name"`
+	Link        string   `xml:"link"`
+}
+
+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"`
+}
+
+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 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 Rss struct {
+	*Feed
+}
+
+// create a new RssItem with a generic Item struct's data
+func newRssItem(i *Item) *RssItem {
+	item := &RssItem{
+		Title:       i.Title,
+		Link:        i.Link.Href,
+		Description: i.Description,
+		Guid:        i.Id,
+		PubDate:     anyTimeFormat(time.RFC1123Z, i.Created, i.Updated),
+	}
+	if len(i.Content) > 0 {
+		item.Content = &RssContent{Content: i.Content}
+	}
+	if i.Source != nil {
+		item.Source = i.Source.Href
+	}
+
+	// Define a closure
+	if i.Enclosure != nil && i.Enclosure.Type != "" && i.Enclosure.Length != "" {
+		item.Enclosure = &RssEnclosure{Url: i.Enclosure.Url, Type: i.Enclosure.Type, Length: i.Enclosure.Length}
+	}
+
+	if i.Author != nil {
+		item.Author = i.Author.Name
+	}
+	return item
+}
+
+// create a new RssFeed with a generic Feed struct's data
+func (r *Rss) RssFeed() *RssFeed {
+	pub := anyTimeFormat(time.RFC1123Z, r.Created, r.Updated)
+	build := anyTimeFormat(time.RFC1123Z, r.Updated)
+	author := ""
+	if r.Author != nil {
+		author = r.Author.Email
+		if len(r.Author.Name) > 0 {
+			author = fmt.Sprintf("%s (%s)", r.Author.Email, r.Author.Name)
+		}
+	}
+
+	var image *RssImage
+	if r.Image != nil {
+		image = &RssImage{Url: r.Image.Url, Title: r.Image.Title, Link: r.Image.Link, Width: r.Image.Width, Height: r.Image.Height}
+	}
+
+	channel := &RssFeed{
+		Title:          r.Title,
+		Link:           r.Link.Href,
+		Description:    r.Description,
+		ManagingEditor: author,
+		PubDate:        pub,
+		LastBuildDate:  build,
+		Copyright:      r.Copyright,
+		Image:          image,
+	}
+	for _, i := range r.Items {
+		channel.Items = append(channel.Items, newRssItem(i))
+	}
+	return channel
+}
+
+// FeedXml returns an XML-Ready object for an Rss object
+func (r *Rss) FeedXml() interface{} {
+	// only generate version 2.0 feeds for now
+	return r.RssFeed().FeedXml()
+
+}
+
+// FeedXml returns an XML-ready object for an RssFeed object
+func (r *RssFeed) FeedXml() interface{} {
+	return &RssFeedXml{
+		Version:          "2.0",
+		Channel:          r,
+		ContentNamespace: "http://purl.org/rss/1.0/modules/content/",
+	}
+}