Add functions to create a new feed and add objects to slices

feed.go

@@ -4,6 +4,7 @@ import (
 	"encoding/xml"
 	"errors"
 	"fmt"
+	"time"
 )
 
 type Feed struct {
@@ -17,18 +18,89 @@ type Feed struct {
 	ID           *ID                 `xml:"id"`
 	Links        []*Link             `xml:"link,omitempty"` // There should be one link with rel "self"
 	Logo         *Logo               `xml:"logo,omitempty"`
-	Rights       *Text               `xml:"rights,omitempty"`
-	Subtitle     *Text               `xml:"subtitle,omitempty"`
-	Title        *Text               `xml:"title"`
+	Rights       Text                `xml:"rights,omitempty"`
+	Subtitle     Text                `xml:"subtitle,omitempty"`
+	Title        Text                `xml:"title"`
 	Updated      *Date               `xml:"updated"`
 	Extensions   []*ExtensionElement `xml:",any,omitempty"`
 	Entries      []*Entry            `xml:"entry,omitempty"`
 }
 
-func (f *Feed) AddExtension(name string, value any) {
-	f.Extensions = append(f.Extensions, &ExtensionElement{XMLName: xml.Name{Local: name}, Value: value})
+// NewFeed creates a new feed
+func NewFeed(title string, updated time.Time) (*Feed, error) {
+	text, err := NewText("text", title)
+	if err != nil {
+		return nil, fmt.Errorf("error creating new feed: %v", err)
 	}
 
+	return &Feed{
+		ID:      NewID(),
+		Title:   text,
+		Updated: NewDate(time.Now()),
+	}, nil
+}
+
+// AddAuthor adds the person as an author to the feed
+func (f *Feed) AddAuthor(p *Person) {
+	if f.Authors == nil {
+		f.Authors = make([]*Person, 1)
+		f.Authors[0] = p
+	} else {
+		f.Authors = append(f.Authors, p)
+	}
+}
+
+// AddCategory adds the category to the feed
+func (f *Feed) AddCategory(c *Category) {
+	if f.Categories == nil {
+		f.Categories = make([]*Category, 1)
+		f.Categories[0] = c
+	} else {
+		f.Categories = append(f.Categories, c)
+	}
+}
+
+// AddContributor adds the contributor to the feed
+func (f *Feed) AddContributor(c *Person) {
+	if f.Contributors == nil {
+		f.Contributors = make([]*Person, 1)
+		f.Contributors[0] = c
+	} else {
+		f.Contributors = append(f.Contributors, c)
+	}
+}
+
+// AddLink adds the link to the feed
+func (f *Feed) AddLink(l *Link) {
+	if f.Links == nil {
+		f.Links = make([]*Link, 1)
+		f.Links[0] = l
+	} else {
+		f.Links = append(f.Links, l)
+	}
+}
+
+// AddExtension adds the extension to the feed
+func (f *Feed) AddExtension(e *ExtensionElement) {
+	if f.Extensions == nil {
+		f.Extensions = make([]*ExtensionElement, 1)
+		f.Extensions[0] = e
+	} else {
+		f.Extensions = append(f.Extensions, e)
+	}
+}
+
+// AddEntry adds the entry to the feed
+func (f *Feed) AddEntry(e *Entry) {
+	if f.Entries == nil {
+		f.Entries = make([]*Entry, 1)
+		f.Entries[0] = e
+	} else {
+		f.Entries = append(f.Entries, e)
+	}
+}
+
+// Check checks the feed for incompatibilities with the Atom standard
 func (f *Feed) Check() error {
 	if f.ID == nil {
 		return errors.New("no id element of feed")
@@ -95,13 +167,13 @@ func (f *Feed) Check() error {
 	}
 
 	if f.Rights != nil {
-		if err := (*f.Rights).Check(); err != nil {
+		if err := f.Rights.Check(); err != nil {
 			return fmt.Errorf("rights element of feed %v: %v", f.ID.URI, err)
 		}
 	}
 
 	if f.Subtitle != nil {
-		if err := (*f.Subtitle).Check(); err != nil {
+		if err := f.Subtitle.Check(); err != nil {
 			return fmt.Errorf("subtitle element of feed %v: %v", f.ID.URI, err)
 		}
 	}
@@ -109,7 +181,7 @@ func (f *Feed) Check() error {
 	if f.Title == nil {
 		return fmt.Errorf("no title element of feed %v", f.ID.URI)
 	} else {
-		if err := (*f.Title).Check(); err != nil {
+		if err := f.Title.Check(); err != nil {
 			return fmt.Errorf("title element of feed %v: %v", f.ID.URI, err)
 		}
 	}
@@ -160,6 +232,7 @@ func (f *Feed) Standardize() {
 	}
 }
 
+// ToXML converts the feed to XML
 func (f *Feed) ToXML(encoding string) (string, error) {
 	xml, err := xml.MarshalIndent(f, "", "  ")
 	if err != nil {