ref: bfc3488b8e8b3dc1ffc6a339ee2dac8dcbdb55a9
dir: /media/mediaType.go/
// Copyright 2017-present The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package media
import (
"encoding/json"
"fmt"
"sort"
"strings"
"github.com/mitchellh/mapstructure"
)
const (
defaultDelimiter = "."
)
// Type (also known as MIME type and content type) is a two-part identifier for
// file formats and format contents transmitted on the Internet.
// For Hugo's use case, we use the top-level type name / subtype name + suffix.
// One example would be image/jpeg+jpg
// If suffix is not provided, the sub type will be used.
// See // https://en.wikipedia.org/wiki/Media_type
type Type struct {
MainType string `json:"mainType"` // i.e. text
SubType string `json:"subType"` // i.e. html
Suffix string `json:"suffix"` // i.e html
Delimiter string `json:"delimiter"` // defaults to "."
}
// FromString creates a new Type given a type sring on the form MainType/SubType and
// an optional suffix, e.g. "text/html" or "text/html+html".
func FromString(t string) (Type, error) {
t = strings.ToLower(t)
parts := strings.Split(t, "/")
if len(parts) != 2 {
return Type{}, fmt.Errorf("cannot parse %q as a media type", t)
}
mainType := parts[0]
subParts := strings.Split(parts[1], "+")
subType := strings.Split(subParts[0], ";")[0]
var suffix string
if len(subParts) == 1 {
suffix = subType
} else {
suffix = subParts[1]
}
return Type{MainType: mainType, SubType: subType, Suffix: suffix, Delimiter: defaultDelimiter}, nil
}
// Type returns a string representing the main- and sub-type of a media type, i.e. "text/css".
// Hugo will register a set of default media types.
// These can be overridden by the user in the configuration,
// by defining a media type with the same Type.
func (m Type) Type() string {
return fmt.Sprintf("%s/%s", m.MainType, m.SubType)
}
func (m Type) String() string {
if m.Suffix != "" {
return fmt.Sprintf("%s/%s+%s", m.MainType, m.SubType, m.Suffix)
}
return fmt.Sprintf("%s/%s", m.MainType, m.SubType)
}
// FullSuffix returns the file suffix with any delimiter prepended.
func (m Type) FullSuffix() string {
return m.Delimiter + m.Suffix
}
var (
CalendarType = Type{"text", "calendar", "ics", defaultDelimiter}
CSSType = Type{"text", "css", "css", defaultDelimiter}
SCSSType = Type{"text", "x-scss", "scss", defaultDelimiter}
SASSType = Type{"text", "x-sass", "sass", defaultDelimiter}
CSVType = Type{"text", "csv", "csv", defaultDelimiter}
HTMLType = Type{"text", "html", "html", defaultDelimiter}
JavascriptType = Type{"application", "javascript", "js", defaultDelimiter}
JSONType = Type{"application", "json", "json", defaultDelimiter}
RSSType = Type{"application", "rss", "xml", defaultDelimiter}
XMLType = Type{"application", "xml", "xml", defaultDelimiter}
// The official MIME type of SVG is image/svg+xml. We currently only support one extension
// per mime type. The workaround in projects is to create multiple media type definitions,
// but we need to improve this to take other known suffixes into account.
// But until then, svg has an svg extension, which is very common. TODO(bep)
SVGType = Type{"image", "svg", "svg", defaultDelimiter}
TextType = Type{"text", "plain", "txt", defaultDelimiter}
OctetType = Type{"application", "octet-stream", "", ""}
)
var DefaultTypes = Types{
CalendarType,
CSSType,
CSVType,
SCSSType,
SASSType,
HTMLType,
JavascriptType,
JSONType,
RSSType,
XMLType,
SVGType,
TextType,
OctetType,
}
func init() {
sort.Sort(DefaultTypes)
}
type Types []Type
func (t Types) Len() int { return len(t) }
func (t Types) Swap(i, j int) { t[i], t[j] = t[j], t[i] }
func (t Types) Less(i, j int) bool { return t[i].Type() < t[j].Type() }
func (t Types) GetByType(tp string) (Type, bool) {
for _, tt := range t {
if strings.EqualFold(tt.Type(), tp) {
return tt, true
}
}
return Type{}, false
}
// GetFirstBySuffix will return the first media type matching the given suffix.
func (t Types) GetFirstBySuffix(suffix string) (Type, bool) {
for _, tt := range t {
if strings.EqualFold(suffix, tt.Suffix) {
return tt, true
}
}
return Type{}, false
}
// GetBySuffix gets a media type given as suffix, e.g. "html".
// It will return false if no format could be found, or if the suffix given
// is ambiguous.
// The lookup is case insensitive.
func (t Types) GetBySuffix(suffix string) (tp Type, found bool) {
for _, tt := range t {
if strings.EqualFold(suffix, tt.Suffix) {
if found {
// ambiguous
found = false
return
}
tp = tt
found = true
}
}
return
}
// DecodeTypes takes a list of media type configurations and merges those,
// in the order given, with the Hugo defaults as the last resort.
func DecodeTypes(maps ...map[string]interface{}) (Types, error) {
m := make(Types, len(DefaultTypes))
copy(m, DefaultTypes)
for _, mm := range maps {
for k, v := range mm {
// It may be tempting to put the full media type in the key, e.g.
// "text/css+css", but that will break the logic below.
if strings.Contains(k, "+") {
return Types{}, fmt.Errorf("media type keys cannot contain any '+' chars. Valid example is %q", "text/css")
}
found := false
for i, vv := range m {
// Match by type, i.e. "text/css"
if strings.EqualFold(k, vv.Type()) {
// Merge it with the existing
if err := mapstructure.WeakDecode(v, &m[i]); err != nil {
return m, err
}
found = true
}
}
if !found {
mediaType, err := FromString(k)
if err != nil {
return m, err
}
if err := mapstructure.WeakDecode(v, &mediaType); err != nil {
return m, err
}
m = append(m, mediaType)
}
}
}
sort.Sort(m)
return m, nil
}
func (m Type) MarshalJSON() ([]byte, error) {
type Alias Type
return json.Marshal(&struct {
Type string `json:"type"`
String string `json:"string"`
Alias
}{
Type: m.Type(),
String: m.String(),
Alias: (Alias)(m),
})
}