opml package

2021-03-16 23:25:51 +00:00 · 2021-03-16 23:25:51 +00:00 · 1e65da9aa4
commit 1e65da9aa4
parent 0d49377879
4 changed files with 148 additions and 58 deletions
--- a/src/opml/builder.go
+++ b/src/opml/builder.go
@ -0,0 +1,83 @@
+package opml
+
+import (
+	"fmt"
+	"html"
+	"strings"
+)
+
+type OPMLBuilder struct {
+	rootfolder *OPMLFolder
+	folders    []*OPMLFolder
+}
+
+type OPMLFolder struct {
+	title string
+	feeds []*OPMLFeed
+}
+
+type OPMLFeed struct {
+	title, description, feedUrl, siteUrl string
+}
+
+func NewBuilder() *OPMLBuilder {
+	return &OPMLBuilder{
+		rootfolder: &OPMLFolder{feeds: make([]*OPMLFeed, 0)},
+		folders:    make([]*OPMLFolder, 0),
+	}	
+}
+
+func (b *OPMLBuilder) AddFeed(title, description, feedUrl, siteUrl string) {
+	b.rootfolder.AddFeed(title, description, feedUrl, siteUrl)
+}
+
+func (b *OPMLBuilder) AddFolder(title string) *OPMLFolder {
+	folder := &OPMLFolder{title: title}
+	b.folders = append(b.folders, folder)
+	return folder
+}
+
+func (f *OPMLFolder) AddFeed(title, description, feedUrl, siteUrl string) {
+	f.feeds = append(f.feeds, &OPMLFeed{title, description, feedUrl, siteUrl})
+}
+
+func (b *OPMLBuilder) String() string {
+	builder := strings.Builder{}
+
+	line := func(s string, args ...string) {
+		if len(args) > 0 {
+			escapedargs := make([]interface{}, len(args))
+			for idx, arg := range args {
+				escapedargs[idx] = html.EscapeString(arg)
+			}
+			s = fmt.Sprintf(s, escapedargs...)
+		}
+		builder.WriteString(s)
+		builder.WriteRune('\n')
+	}
+	feedline := func(feed *OPMLFeed, indent int) {
+		line(
+			strings.Repeat(" ", indent) + `<outline type="rss" text="%s" description="%s" xmlUrl="%s" htmlUrl="%s"/>`,
+			feed.title, feed.description,
+			feed.feedUrl, feed.siteUrl,
+		)
+	}
+	line(`<?xml version="1.0" encoding="UTF-8"?>`)
+	line(`<opml version="1.1">`)
+	line(`<head><title>Subscriptions</title></head>`)
+	line(`<body>`)
+	for _, folder := range b.folders {
+		line(`  <outline text="%s">`, folder.title)
+		for _, feed := range folder.feeds {
+			feedline(feed, 4)
+		}
+		line(`  </outline>`)
+	}
+	for _, feed := range b.rootfolder.feeds {
+		feedline(feed, 2)
+	}
+	line(`</body>`)
+	line(`</opml>`)
+
+	return builder.String()
+}
--- a/src/opml/builder_test.go
+++ b/src/opml/builder_test.go
@ -0,0 +1,30 @@
+package opml
+
+import "testing"
+
+var sample = `<?xml version="1.0" encoding="UTF-8"?>
+<opml version="1.1">
+<head><title>Subscriptions</title></head>
+<body>
+  <outline text="sub">
+    <outline type="rss" text="subtitle1" description="sub1" xmlUrl="https://foo.com/feed.xml" htmlUrl="https://foo.com/"/>
+    <outline type="rss" text="&amp;&gt;" description="&lt;&gt;" xmlUrl="https://bar.com/feed.xml" htmlUrl="https://bar.com/"/>
+  </outline>
+  <outline type="rss" text="title1" description="desc1" xmlUrl="https://example.com/feed.xml" htmlUrl="https://example.com/"/>
+</body>
+</opml>
+`
+
+func TestOPMLBuilder(t *testing.T) {
+	builder := NewBuilder()
+	builder.AddFeed("title1", "desc1", "https://example.com/feed.xml", "https://example.com/")
+
+	folder := builder.AddFolder("sub")
+	folder.AddFeed("subtitle1", "sub1", "https://foo.com/feed.xml", "https://foo.com/")
+	folder.AddFeed("&>", "<>", "https://bar.com/feed.xml", "https://bar.com/")
+
+	output := builder.String()
+	if output != sample {
+		t.Errorf("\n=== expected:\n%s\n=== got:\n%s\n===", sample, output)
+	}
+}
--- a/src/opml/parser.go
+++ b/src/opml/parser.go
@ -0,0 +1,42 @@
+package opml
+
+import (
+	"encoding/xml"
+	"io"
+)
+
+type OPML struct {
+	XMLName  xml.Name  `xml:"opml"`
+	Version  string    `xml:"version,attr"`
+	Outlines []Outline `xml:"body>outline"`
+}
+
+type Outline struct {
+	Type        string    `xml:"type,attr,omitempty"`
+	Title       string    `xml:"text,attr"`
+	FeedURL     string    `xml:"xmlUrl,attr,omitempty"`
+	SiteURL     string    `xml:"htmlUrl,attr,omitempty"`
+	Description string    `xml:"description,attr,omitempty"`
+	Outlines    []Outline `xml:"outline,omitempty"`
+}
+
+func (o Outline) AllFeeds() []Outline {
+	result := make([]Outline, 0)
+	for _, sub := range o.Outlines {
+		if sub.Type == "rss" {
+			result = append(result, sub)
+		} else {
+			result = append(result, sub.AllFeeds()...)
+		}
+	}
+	return result
+}
+
+func Parse(r io.Reader) (*OPML, error) {
+	feeds := new(OPML)
+	decoder := xml.NewDecoder(r)
+	decoder.Entity = xml.HTMLEntity
+	decoder.Strict = false
+	err := decoder.Decode(&feeds)
+	return feeds, err
+}