Initial code commit

atom/rss.go

@@ -0,0 +1,79 @@
+package atom
+
+import (
+	"errors"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/gorilla/feeds"
+)
+
+// Indices indicates which capture group in the
+// regex-parsed HTML to reference for each Atom field.
+// An empty slice will use a blank/default value.
+// For the slices of strings, these will be appended between
+// captured group text.
+type IndicesT struct {
+	TitleC       []string
+	TitleI       []int8
+	LinkC        []string
+	LinkI        []int8
+	DescriptionC []string
+	DescriptionI []int8
+	AuthorNameC  []string
+	AuthorNameI  []int8
+	AuthorEmailC []string
+	AuthorEmailI []int8
+}
+
+func GetFromHTML(feed *feeds.Feed, rawHTML *string, regexString string, infoIndices IndicesT, maxFeedItems int) (*string, error) {
+	now := time.Now()
+	r := regexp.MustCompile(regexString)
+	newsItems := r.FindAllString(*rawHTML, 5)
+	for i, item := range newsItems {
+		info := r.FindStringSubmatch(item)
+		link := stitchFields(info, infoIndices.LinkC, infoIndices.LinkI)
+		feedItem := &feeds.Item{
+			Title:       stitchFields(info, infoIndices.TitleC, infoIndices.TitleI),
+			Link:        &feeds.Link{Href: link},
+			Id:          "urn:backtoneid:" + strconv.Itoa(i) + ":" + link,
+			Description: stitchFields(info, infoIndices.DescriptionC, infoIndices.DescriptionI),
+			Author: &feeds.Author{
+				Name:  stitchFields(info, infoIndices.AuthorNameC, infoIndices.AuthorNameI),
+				Email: stitchFields(info, infoIndices.AuthorEmailC, infoIndices.AuthorEmailI),
+			},
+			Created: now,
+		}
+		feed.Items = append(feed.Items, feedItem)
+		if i == maxFeedItems {
+			break
+		}
+	}
+	atom, err := feed.ToAtom()
+	if err != nil {
+		return nil, errors.New("unable to create Atom RSS feed: " + err.Error())
+	}
+	return &atom, nil
+}
+
+func stitchFields(info []string, connectors []string, indices []int8) string {
+	var output strings.Builder
+	if len(connectors) > 0 {
+		for i := range connectors {
+			output.WriteString(connectors[i])
+			if len(indices) >= i+1 {
+				output.WriteString(info[indices[i]])
+			}
+		}
+	} else {
+		for i := range indices {
+			if i > 0 {
+				output.WriteString(" | ")
+			}
+			output.WriteString(info[indices[i]])
+		}
+	}
+	return output.String()
+}