support RSS feed generation

5 files changed, 512 insertions, 0 deletions

diff --git a/vendor/github.com/gorilla/feeds/atom.go b/vendor/github.com/gorilla/feeds/atom.go
new file mode 100644
index 0000000..512976b
--- /dev/null
+++ b/vendor/github.com/gorilla/feeds/atom.go
@@ -0,0 +1,163 @@
+package feeds
+
+import (
+	"encoding/xml"
+	"fmt"
+	"net/url"
+	"strconv"
+	"time"
+)
+
+// Generates Atom feed as XML
+
+const ns = "http://www.w3.org/2005/Atom"
+
+type AtomPerson struct {
+	Name  string `xml:"name,omitempty"`
+	Uri   string `xml:"uri,omitempty"`
+	Email string `xml:"email,omitempty"`
+}
+
+type AtomSummary struct {
+	XMLName xml.Name `xml:"summary"`
+	Content string   `xml:",chardata"`
+	Type    string   `xml:"type,attr"`
+}
+
+type AtomContent struct {
+	XMLName xml.Name `xml:"content"`
+	Content string   `xml:",chardata"`
+	Type    string   `xml:"type,attr"`
+}
+
+type AtomAuthor struct {
+	XMLName xml.Name `xml:"author"`
+	AtomPerson
+}
+
+type AtomContributor struct {
+	XMLName xml.Name `xml:"contributor"`
+	AtomPerson
+}
+
+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
+	Link        *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 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"`
+}
+
+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
+}
+
+type Atom struct {
+	*Feed
+}
+
+func newAtomEntry(i *Item) *AtomEntry {
+	id := i.Id
+	// assume the description is html
+	c := &AtomContent{Content: i.Description, Type: "html"}
+
+	if len(id) == 0 {
+		// if there's no id set, try to create one, either from data or just a uuid
+		if len(i.Link.Href) > 0 && (!i.Created.IsZero() || !i.Updated.IsZero()) {
+			dateStr := anyTimeFormat("2006-01-02", i.Updated, i.Created)
+			host, path := i.Link.Href, "/invalid.html"
+			if url, err := url.Parse(i.Link.Href); err == nil {
+				host, path = url.Host, url.Path
+			}
+			id = fmt.Sprintf("tag:%s,%s:%s", host, dateStr, path)
+		} else {
+			id = "urn:uuid:" + NewUUID().String()
+		}
+	}
+	var name, email string
+	if i.Author != nil {
+		name, email = i.Author.Name, i.Author.Email
+	}
+
+	x := &AtomEntry{
+		Title:   i.Title,
+		Link:    &AtomLink{Href: i.Link.Href, Rel: i.Link.Rel, Type: i.Link.Type},
+		Content: c,
+		Id:      id,
+		Updated: anyTimeFormat(time.RFC3339, i.Updated, i.Created),
+	}
+
+	intLength, err := strconv.ParseInt(i.Link.Length, 10, 64)
+
+	if err == nil && (intLength > 0 || i.Link.Type != "") {
+		i.Link.Rel = "enclosure"
+		x.Link = &AtomLink{Href: i.Link.Href, Rel: i.Link.Rel, Type: i.Link.Type, Length: i.Link.Length}
+	}
+
+	if len(name) > 0 || len(email) > 0 {
+		x.Author = &AtomAuthor{AtomPerson: AtomPerson{Name: name, Email: email}}
+	}
+	return x
+}
+
+// create a new AtomFeed with a generic Feed struct's data
+func (a *Atom) AtomFeed() *AtomFeed {
+	updated := anyTimeFormat(time.RFC3339, a.Updated, a.Created)
+	feed := &AtomFeed{
+		Xmlns:    ns,
+		Title:    a.Title,
+		Link:     &AtomLink{Href: a.Link.Href, Rel: a.Link.Rel},
+		Subtitle: a.Description,
+		Id:       a.Link.Href,
+		Updated:  updated,
+		Rights:   a.Copyright,
+	}
+	if a.Author != nil {
+		feed.Author = &AtomAuthor{AtomPerson: AtomPerson{Name: a.Author.Name, Email: a.Author.Email}}
+	}
+	for _, e := range a.Items {
+		feed.Entries = append(feed.Entries, newAtomEntry(e))
+	}
+	return feed
+}
+
+// return an XML-Ready object for an Atom object
+func (a *Atom) FeedXml() interface{} {
+	return a.AtomFeed()
+}
+
+// return an XML-ready object for an AtomFeed object
+func (a *AtomFeed) FeedXml() interface{} {
+	return a
+}
diff --git a/vendor/github.com/gorilla/feeds/doc.go b/vendor/github.com/gorilla/feeds/doc.go
new file mode 100644
index 0000000..5b005ea
--- /dev/null
+++ b/vendor/github.com/gorilla/feeds/doc.go
@@ -0,0 +1,70 @@
+/*
+Syndication (feed) generator library for golang.
+
+Installing
+
+	go get github.com/gorilla/feeds
+
+Feeds provides a simple, generic Feed interface with a generic Item object as well as RSS and Atom specific RssFeed and AtomFeed 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/gorilla/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 or RSS versions of this feed easily
+
+	atom, err := feed.ToAtom()
+	rss, err := feed.ToRss()
+
+You can also get access to the underlying objects that feeds uses to export its XML
+
+	atomFeed := &Atom{feed}.AtomFeed()
+	rssFeed := &Rss{feed}.RssFeed()
+
+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/gorilla/feeds)"
+	rss, err := ToXML(rssFeed)
+
+*/
+package feeds
diff --git a/vendor/github.com/gorilla/feeds/feed.go b/vendor/github.com/gorilla/feeds/feed.go
new file mode 100644
index 0000000..fe4833e
--- /dev/null
+++ b/vendor/github.com/gorilla/feeds/feed.go
@@ -0,0 +1,106 @@
+package feeds
+
+import (
+	"encoding/xml"
+	"io"
+	"time"
+)
+
+type Link struct {
+	Href, Rel, Type, Length string
+}
+
+type Author struct {
+	Name, Email string
+}
+
+type Item struct {
+	Title       string
+	Link        *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
+}
+
+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
+}
+
+// add a new Item to a Feed
+func (f *Feed) Add(item *Item) {
+	f.Items = append(f.Items, item)
+}
+
+// returns the first non-zero time formatted as a string or ""
+func anyTimeFormat(format string, times ...time.Time) string {
+	for _, t := range times {
+		if !t.IsZero() {
+			return t.Format(format)
+		}
+	}
+	return ""
+}
+
+// interface used by ToXML to get a object suitable for exporting XML.
+type XmlFeed interface {
+	FeedXml() interface{}
+}
+
+// turn a feed object (either a Feed, AtomFeed, or RssFeed) into xml
+// returns an error if xml marshaling fails
+func ToXML(feed XmlFeed) (string, error) {
+	x := feed.FeedXml()
+	data, err := xml.MarshalIndent(x, "", "  ")
+	if err != nil {
+		return "", err
+	}
+	// strip empty line from default xml header
+	s := xml.Header[:len(xml.Header)-1] + string(data)
+	return s, nil
+}
+
+// Write a feed object (either a Feed, AtomFeed, or RssFeed) as XML into
+// the writer. Returns an error if XML marshaling fails.
+func WriteXML(feed XmlFeed, w io.Writer) error {
+	x := feed.FeedXml()
+	// write default xml header, without the newline
+	if _, err := w.Write([]byte(xml.Header[:len(xml.Header)-1])); err != nil {
+		return err
+	}
+	e := xml.NewEncoder(w)
+	e.Indent("", "  ")
+	return e.Encode(x)
+}
+
+// creates an Atom representation of this feed
+func (f *Feed) ToAtom() (string, error) {
+	a := &Atom{f}
+	return ToXML(a)
+}
+
+// Writes an Atom representation of this feed to the writer.
+func (f *Feed) WriteAtom(w io.Writer) error {
+	return WriteXML(&Atom{f}, w)
+}
+
+// creates an Rss representation of this feed
+func (f *Feed) ToRss() (string, error) {
+	r := &Rss{f}
+	return ToXML(r)
+}
+
+// Writes an RSS representation of this feed to the writer.
+func (f *Feed) WriteRss(w io.Writer) error {
+	return WriteXML(&Rss{f}, w)
+}
diff --git a/vendor/github.com/gorilla/feeds/rss.go b/vendor/github.com/gorilla/feeds/rss.go
new file mode 100644
index 0000000..3381f74
--- /dev/null
+++ b/vendor/github.com/gorilla/feeds/rss.go
@@ -0,0 +1,146 @@
+package feeds
+
+// rss support
+// validation done according to spec here:
+//    http://cyber.law.harvard.edu/rss/rss.html
+
+import (
+	"encoding/xml"
+	"fmt"
+	"strconv"
+	"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"`
+	Channel *RssFeed
+}
+
+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
+}
+
+type RssItem struct {
+	XMLName     xml.Name `xml:"item"`
+	Title       string   `xml:"title"`       // required
+	Link        string   `xml:"link"`        // required
+	Description string   `xml:"description"` // required
+	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),
+	}
+
+	intLength, err := strconv.ParseInt(i.Link.Length, 10, 64)
+
+	if err == nil && (intLength > 0 || i.Link.Type != "") {
+		item.Enclosure = &RssEnclosure{Url: i.Link.Href, Type: i.Link.Type, Length: i.Link.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)
+		}
+	}
+
+	channel := &RssFeed{
+		Title:          r.Title,
+		Link:           r.Link.Href,
+		Description:    r.Description,
+		ManagingEditor: author,
+		PubDate:        pub,
+		LastBuildDate:  build,
+		Copyright:      r.Copyright,
+	}
+	for _, i := range r.Items {
+		channel.Items = append(channel.Items, newRssItem(i))
+	}
+	return channel
+}
+
+// return 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()
+
+}
+
+// return an XML-ready object for an RssFeed object
+func (r *RssFeed) FeedXml() interface{} {
+	return &rssFeedXml{Version: "2.0", Channel: r}
+}
diff --git a/vendor/github.com/gorilla/feeds/uuid.go b/vendor/github.com/gorilla/feeds/uuid.go
new file mode 100644
index 0000000..51bbafe
--- /dev/null
+++ b/vendor/github.com/gorilla/feeds/uuid.go
@@ -0,0 +1,27 @@
+package feeds
+
+// relevant bits from https://github.com/abneptis/GoUUID/blob/master/uuid.go
+
+import (
+	"crypto/rand"
+	"fmt"
+)
+
+type UUID [16]byte
+
+// create a new uuid v4
+func NewUUID() *UUID {
+	u := &UUID{}
+	_, err := rand.Read(u[:16])
+	if err != nil {
+		panic(err)
+	}
+
+	u[8] = (u[8] | 0x80) & 0xBf
+	u[6] = (u[6] | 0x40) & 0x4f
+	return u
+}
+
+func (u *UUID) String() string {
+	return fmt.Sprintf("%x-%x-%x-%x-%x", u[:4], u[4:6], u[6:8], u[8:10], u[10:])
+}