// serveNav serves some navigation links (prev, next, up) if the
// pr.subject is member of a collection (its parent has members).
// It is meant to be called from serveFile.
func (pr *publishRequest) serveNav() error {
// first get the parent path and blob
parentPath, parentbr, err := pr.parent()
if err != nil {
return fmt.Errorf("Errors building nav links for %s: %v", pr.subject, err)
}
parentNav := fmt.Sprintf("[<a href='%s'>up</a>]", strings.TrimSuffix(parentPath, resSeparator))
// describe the parent so we get the siblings (members of the parent)
dr := pr.ph.Search.NewDescribeRequest()
dr.Describe(parentbr, 3)
parentRes, err := dr.Result()
if err != nil {
return fmt.Errorf("Errors loading %s, permanode %s: %v, %#v", pr.req.URL, pr.subject, err, err)
}
members := parentRes[parentbr.String()].Members()
if len(members) == 0 {
pr.pf("<div class='camlifile'>[<a href='%s'>up</a>]</div>", parentNav)
return nil
}
pos := 0
var prev, next *blobref.BlobRef
for k, member := range members {
if member.BlobRef.String() == pr.subject.String() {
pos = k
break
}
}
if pos > 0 {
prev = members[pos-1].BlobRef
}
if pos < len(members)-1 {
next = members[pos+1].BlobRef
}
if prev != nil || next != nil {
var prevNav, nextNav string
if prev != nil {
prevNav = fmt.Sprintf("[<a href='%s/h%s'>prev</a>]",
parentPath, prev.DigestPrefix(10))
}
if next != nil {
nextNav = fmt.Sprintf("[<a href='%s/h%s'>next</a>]",
parentPath, next.DigestPrefix(10))
}
pr.pf("<div class='camlifile'>%s %s %s</div>", parentNav, prevNav, nextNav)
}
return nil
}
func (pr *publishRequest) memberPath(member *blobref.BlobRef) string {
return addPathComponent(pr.subjectBasePath, "/h"+member.DigestPrefix(10))
}