107 lines
2.7 KiB
Go
107 lines
2.7 KiB
Go
// Package gempub implements the gempub 1.0.0 specification as described here: https://codeberg.org/oppenlab/gempub
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package gempub
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import (
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"bufio"
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"errors"
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"fmt"
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"io"
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"strings"
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"time"
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)
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type Metadata struct {
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Title string // mandatory title of the work
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GpubVersion string // mandatory Gempub format version: 1.0.0
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Index string // path to index.gmi, if none is specified it should be assumed to be in the root
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Author string // author of the work
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Language string // BCP 47 language code
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Charset string // if not set, assume UTF-8
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Description string // human-readable description
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Published time.Time // YYYY when date is unknown
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PublishDate time.Time // YYYY-MM-DD eg. 2006-01-02
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RevisionDate time.Time // YYYY-MM-DD eg. 2006-01-02
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Copyright string // copyright of the book
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License string // license of the book Version string a // human readable only, not meant to be parsed
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Cover string // a JPG or PNG image which can be anywhere in the directory structure
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}
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var (
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ErrNoTitle = errors.New("gempub: no title in document")
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)
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func loadDateOrYear(when string) (t time.Time, err error) {
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if len(when) == 4 {
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t, err = time.Parse("2006", when)
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return
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}
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t, err = time.Parse("2006-01-02", when)
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return
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}
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func (m Metadata) Valid() error {
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switch {
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case m.Title == "":
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return ErrNoTitle
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case m.GpubVersion != "1.0.0":
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return fmt.Errorf("gempub: wrong gempub version: %v", m.GpubVersion)
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}
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return nil
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}
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func ReadMetadata(r io.Reader) (*Metadata, error) {
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var result Metadata
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sc := bufio.NewScanner(r)
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for sc.Scan() {
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line := sc.Text()
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sp := strings.SplitN(line, ":", 2)
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key, val := sp[0], sp[1]
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val = strings.TrimSpace(val)
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switch key {
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case "title":
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result.Title = val
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case "gpubVersion":
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result.GpubVersion = val
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case "index":
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result.Index = val
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case "author":
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result.Author = val
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case "language":
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result.Language = val
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case "charset":
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result.Charset = val
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case "description":
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result.Description = val
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case "published":
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when, err := loadDateOrYear(val)
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if err != nil {
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return nil, fmt.Errorf("gempub: can't understand date %q: %v", val, err)
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}
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result.Published = when
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case "publishDate":
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when, err := loadDateOrYear(val)
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if err != nil {
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return nil, fmt.Errorf("gempub: can't understand date %q: %v", val, err)
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}
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result.PublishDate = when
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case "revisionDate":
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when, err := loadDateOrYear(val)
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if err != nil {
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return nil, fmt.Errorf("gempub: can't understand date %q: %v", val, err)
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}
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result.RevisionDate = when
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case "copyright":
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result.Copyright = val
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case "license":
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result.License = val
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case "cover":
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result.Cover = val
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}
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}
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return &result, result.Valid()
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}
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