[feature] Support feed item images (#41)

* Add support for podcast-centered tags
* Adding proper support for Enclosure and and Image tags, which didn't seem to generate properly (might have been a bug on my end but I'm not sure).
* Enclosure.Length from string to int
* Revert change from string to int for Enclosure length
* Accidently changed err == to != for enclosure & author
* Update README to reflect fork goals
* List of tags to implement
* fix RSS image when no Image is mentioned in the Feed
* do not assume that a Link with a field Type is an Enclosure
* expected tests
* better handling of enclosures
* fix package
* Fixes as requested
* Fix travis build error

Author: gmemstr

README.md

@@ -1,5 +1,5 @@
 ## gorilla/feeds
-[![GoDoc](https://godoc.org/github.com/gorilla/feeds?status.svg)](https://godoc.org/github.com/gorilla/feeds) [![Build Status](https://travis-ci.org/gorilla/feeds.png?branch=master)](https://travis-ci.org/gorilla/feeds)
+[![GoDoc](https://godoc.org/github.com/gorilla/feeds?status.svg)](https://godoc.org/github.com/gorilla/feeds)
 
 feeds is a web feed generator library for generating RSS, Atom and JSON feeds from Go
 applications.

atom.go

@@ -4,7 +4,6 @@ import (
 	"encoding/xml"
 	"fmt"
 	"net/url"
-	"strconv"
 	"time"
 )
 
@@ -52,11 +51,12 @@ type AtomEntry struct {
 	Source      string `xml:"source,omitempty"`
 	Published   string `xml:"published,omitempty"`
 	Contributor *AtomContributor
-	Link        *AtomLink    // required if no child 'content' elements
+	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
 }
 
+// Multiple links with different rel can coexist
 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"`
@@ -110,19 +110,20 @@ func newAtomEntry(i *Item) *AtomEntry {
 		name, email = i.Author.Name, i.Author.Email
 	}
 
+	link_rel := i.Link.Rel
+	if link_rel == "" {
+		link_rel = "alternate"
+	}
 	x := &AtomEntry{
 		Title:   i.Title,
-		Link:    &AtomLink{Href: i.Link.Href, Rel: i.Link.Rel, Type: i.Link.Type},
+		Links:   []AtomLink{{Href: i.Link.Href, Rel: 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 i.Enclosure != nil && link_rel != "enclosure" {
+		x.Links = append(x.Links, AtomLink{Href: i.Enclosure.Url, Rel: "enclosure", Type: i.Enclosure.Type, Length: i.Enclosure.Length})
 	}
 
 	if len(name) > 0 || len(email) > 0 {

feed.go

@@ -15,6 +15,15 @@ type Author struct {
 	Name, Email string
 }
 
+type Image struct {
+	Url, Title, Link string
+	Width, Height    int
+}
+
+type Enclosure struct {
+	Url, Length, Type string
+}
+
 type Item struct {
 	Title       string
 	Link        *Link
@@ -24,6 +33,7 @@ type Item struct {
 	Id          string // used as guid in rss, id in atom
 	Updated     time.Time
 	Created     time.Time
+	Enclosure   *Enclosure
 }
 
 type Feed struct {
@@ -37,6 +47,7 @@ type Feed struct {
 	Subtitle    string
 	Items       []*Item
 	Copyright   string
+	Image       *Image
 }
 
 // add a new Item to a Feed

feed_test.go

@@ -22,7 +22,7 @@ var atomOutput = `<?xml version="1.0" encoding="UTF-8"?><feed xmlns="http://www.
     <updated>2013-01-16T21:52:35-05:00</updated>
     <id>tag:jmoiron.net,2013-01-16:/blog/limiting-concurrency-in-go/</id>
     <content type="html">A discussion on controlled parallelism in golang</content>
-    <link href="http://jmoiron.net/blog/limiting-concurrency-in-go/"></link>
+    <link href="http://jmoiron.net/blog/limiting-concurrency-in-go/" rel="alternate"></link>
     <author>
       <name>Jason Moiron</name>
       <email>jmoiron@jmoiron.net</email>
@@ -33,28 +33,30 @@ var atomOutput = `<?xml version="1.0" encoding="UTF-8"?><feed xmlns="http://www.
     <updated>2013-01-16T21:52:35-05:00</updated>
     <id>tag:jmoiron.net,2013-01-16:/blog/logicless-template-redux/</id>
     <content type="html">More thoughts on logicless templates</content>
-    <link href="http://jmoiron.net/blog/logicless-template-redux/"></link>
+    <link href="http://jmoiron.net/blog/logicless-template-redux/" rel="alternate"></link>
   </entry>
   <entry>
     <title>Idiomatic Code Reuse in Go</title>
     <updated>2013-01-16T21:52:35-05:00</updated>
     <id>tag:jmoiron.net,2013-01-16:/blog/idiomatic-code-reuse-in-go/</id>
     <content type="html">How to use interfaces &lt;em&gt;effectively&lt;/em&gt;</content>
-    <link href="http://jmoiron.net/blog/idiomatic-code-reuse-in-go/"></link>
+    <link href="http://jmoiron.net/blog/idiomatic-code-reuse-in-go/" rel="alternate"></link>
+    <link href="http://example.com/cover.jpg" rel="enclosure" type="image/jpg" length="123456"></link>
   </entry>
   <entry>
     <title>Never Gonna Give You Up Mp3</title>
     <updated>2013-01-16T21:52:35-05:00</updated>
     <id>tag:example.com,2013-01-16:/RickRoll.mp3</id>
     <content type="html">Never gonna give you up - Never gonna let you down.</content>
+    <link href="http://example.com/RickRoll.mp3" rel="alternate"></link>
     <link href="http://example.com/RickRoll.mp3" rel="enclosure" type="audio/mpeg" length="123456"></link>
   </entry>
   <entry>
     <title>String formatting in Go</title>
     <updated>2013-01-16T21:52:35-05:00</updated>
     <id>tag:example.com,2013-01-16:/strings</id>
     <content type="html">How to use things like %s, %v, %d, etc.</content>
-    <link href="http://example.com/strings"></link>
+    <link href="http://example.com/strings" rel="alternate"></link>
   </entry>
 </feed>`
 
@@ -83,6 +85,7 @@ var rssOutput = `<?xml version="1.0" encoding="UTF-8"?><rss version="2.0">
       <title>Idiomatic Code Reuse in Go</title>
       <link>http://jmoiron.net/blog/idiomatic-code-reuse-in-go/</link>
       <description>How to use interfaces &lt;em&gt;effectively&lt;/em&gt;</description>
+      <enclosure url="http://example.com/cover.jpg" length="123456" type="image/jpg"></enclosure>
       <pubDate>Wed, 16 Jan 2013 21:52:35 -0500</pubDate>
     </item>
     <item>
@@ -132,6 +135,7 @@ var jsonOutput = `{
       "url": "http://jmoiron.net/blog/idiomatic-code-reuse-in-go/",
       "title": "Idiomatic Code Reuse in Go",
       "summary": "How to use interfaces \u003cem\u003eeffectively\u003c/em\u003e",
+      "image": "http://example.com/cover.jpg",
       "date_published": "2013-01-16T21:52:35-05:00"
     },
     {
@@ -186,11 +190,13 @@ func TestFeed(t *testing.T) {
 			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>",
+			Enclosure:   &Enclosure{Url: "http://example.com/cover.jpg", Length: "123456", Type: "image/jpg"},
 			Created:     now,
 		},
 		{
 			Title:       "Never Gonna Give You Up Mp3",
-			Link:        &Link{Href: "http://example.com/RickRoll.mp3", Length: "123456", Type: "audio/mpeg"},
+			Link:        &Link{Href: "http://example.com/RickRoll.mp3"},
+			Enclosure:   &Enclosure{Url: "http://example.com/RickRoll.mp3", Length: "123456", Type: "audio/mpeg"},
 			Description: "Never gonna give you up - Never gonna let you down.",
 			Created:     now,
 		},

json.go

@@ -2,6 +2,7 @@ package feeds
 
 import (
 	"encoding/json"
+	"strings"
 	"time"
 )
 
@@ -172,6 +173,9 @@ func newJSONItem(i *Item) *JSONItem {
 	if !i.Updated.IsZero() {
 		item.ModifiedDate = &i.Created
 	}
+	if i.Enclosure != nil && strings.HasPrefix(i.Enclosure.Type, "image/") {
+		item.Image = i.Enclosure.Url
+	}
 
 	return item
 }

rss.go

@@ -7,7 +7,6 @@ package feeds
 import (
 	"encoding/xml"
 	"fmt"
-	"strconv"
 	"time"
 )
 
@@ -98,11 +97,11 @@ func newRssItem(i *Item) *RssItem {
 		item.Source = i.Source.Href
 	}
 
-	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}
+	// 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
 	}
@@ -121,6 +120,11 @@ func (r *Rss) RssFeed() *RssFeed {
 		}
 	}
 
+	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,
@@ -129,6 +133,7 @@ func (r *Rss) RssFeed() *RssFeed {
 		PubDate:        pub,
 		LastBuildDate:  build,
 		Copyright:      r.Copyright,
+		Image:          image,
 	}
 	for _, i := range r.Items {
 		channel.Items = append(channel.Items, newRssItem(i))

to-implement.md

@@ -0,0 +1,20 @@
+[Full iTunes list](https://help.apple.com/itc/podcasts_connect/#/itcb54353390)
+
+[Example of ideal iTunes RSS feed](https://help.apple.com/itc/podcasts_connect/#/itcbaf351599)
+
+```
+<itunes:author>
+<itunes:block>
+<itunes:catergory>
+<itunes:image>
+<itunes:duration>
+<itunes:explicit>
+<itunes:isClosedCaptioned>
+<itunes:order>
+<itunes:complete>
+<itunes:new-feed-url>
+<itunes:owner>
+<itunes:subtitle>
+<itunes:summary>
+<language>
+```