diff options
| -rw-r--r-- | cmd/iiifdownloader/main.go | 93 |
1 files changed, 83 insertions, 10 deletions
diff --git a/cmd/iiifdownloader/main.go b/cmd/iiifdownloader/main.go index cccc293..57247cc 100644 --- a/cmd/iiifdownloader/main.go +++ b/cmd/iiifdownloader/main.go @@ -1,6 +1,7 @@ package main import ( + "encoding/json" "encoding/xml" "flag" "fmt" @@ -11,6 +12,7 @@ import ( "net/url" "os" "path" + "strconv" "strings" ) @@ -55,6 +57,9 @@ func filesAreIdentical(fn1, fn2 string) (bool, error) { return true, nil } +// parseMets downloads and parses an XML encoded METS file, +// returning a list of image URLs. +// Example URL: https://daten.digitale-sammlungen.de/~db/mets/bsb10132387_mets.xml func parseMets(u string) ([]string, error) { var urls []string @@ -65,7 +70,6 @@ func parseMets(u string) ([]string, error) { Files []struct { Url string `xml:"href,attr"` } `xml:"file>FLocat"` - XMLName xml.Name `xml:"fileGrp"` } `xml:"fileSec>fileGrp"` } @@ -101,14 +105,83 @@ func parseMets(u string) ([]string, error) { return urls, nil } -func dlPage(bookdir, u string) error { +// parseIIIFManifest downloads and parses a JSON encoded IIIF +// Manifest file, returning a list of image URLs. +// Example URL: https://api.digitale-sammlungen.de/iiif/presentation/v2/bsb10132387/manifest +func parseIIIFManifest(u string) ([]string, error) { + var urls []string + + // designed to be unmarshalled by encoding/json's Unmarshal() + type iiifManifest struct { + Sequences []struct { + Canvases []struct { + Images []struct { + Resource struct { + Id string `json:"@id"` + } + } + } + } + } + + resp, err := http.Get(u) + if err != nil { + return urls, fmt.Errorf("Error downloading IIIF manifest %s: %v", u, err) + } + defer resp.Body.Close() + + if resp.StatusCode != http.StatusOK { + return urls, fmt.Errorf("Error downloading IIIF manifest %s: %v", u, err) + } + + b, err := ioutil.ReadAll(resp.Body) + if err != nil { + return urls, fmt.Errorf("Error reading IIIF manifest %s: %v", u, err) + } + + v := iiifManifest{} + err = json.Unmarshal(b, &v) + if err != nil { + return urls, fmt.Errorf("Error parsing IIIF manifest %s: %v", u, err) + } + + for _, canvas := range v.Sequences[0].Canvases { + for _, image := range canvas.Images { + urls = append(urls, image.Resource.Id) + } + } + + return urls, nil +} + +func urlToPgName(u string) string { + safe := strings.Replace(u, "/", "_", -1) + b := path.Base(u) - ext := path.Ext(u) - if len(ext) == 0 { - ext = "jpg" + if b != "default.jpg" { + return b + } + + f := strings.Split(u, "/") + if len(f) < 5 { + return safe } - field := strings.Split(b, ".") - name := field[0][len(field[0])-4:] + "." + ext + name := f[len(f) - 5] + + f2 := strings.Split(name, "_") + if len(f2) < 2 { + return safe + } + pgnum, err := strconv.Atoi(f2[1]) + if err != nil { + return safe + } + + return fmt.Sprintf("%04d.jpg", pgnum) +} + +func dlPage(bookdir, u string) error { + name := urlToPgName(u) fn := path.Join(bookdir, name) fmt.Printf("Downloading page %s to %s\n", u, fn) @@ -273,11 +346,11 @@ func main() { } bookid := f[0] bookdir = bookid - metsurl := "https://daten.digitale-sammlungen.de/~db/mets/" + bookid + "_mets.xml" + iiifurl := "https://api.digitale-sammlungen.de/iiif/presentation/v2/" + bookid + "/manifest" - pgUrls, err = parseMets(metsurl) + pgUrls, err = parseIIIFManifest(iiifurl) if err != nil { - log.Fatalf("Error parsing mets url %s: %v\n", metsurl, err) + log.Fatalf("Error parsing IIIF manifest url %s: %v\n", iiifurl, err) } case strings.HasPrefix(u, dfgPrefix): // dfg can have a url encoded mets url in several parts of the viewer url |