hugo/parser/metadecoders/format.go
2020-12-03 13:12:58 +01:00

110 lines
2.5 KiB
Go

// Copyright 2018 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 metadecoders
import (
"path/filepath"
"strings"
"github.com/gohugoio/hugo/media"
)
type Format string
const (
// These are the supported metdata formats in Hugo. Most of these are also
// supported as /data formats.
ORG Format = "org"
JSON Format = "json"
TOML Format = "toml"
YAML Format = "yaml"
CSV Format = "csv"
)
// FormatFromString turns formatStr, typically a file extension without any ".",
// into a Format. It returns an empty string for unknown formats.
func FormatFromString(formatStr string) Format {
formatStr = strings.ToLower(formatStr)
if strings.Contains(formatStr, ".") {
// Assume a filename
formatStr = strings.TrimPrefix(filepath.Ext(formatStr), ".")
}
switch formatStr {
case "yaml", "yml":
return YAML
case "json":
return JSON
case "toml":
return TOML
case "org":
return ORG
case "csv":
return CSV
}
return ""
}
// FormatFromMediaType gets the Format given a MIME type, empty string
// if unknown.
func FormatFromMediaType(m media.Type) Format {
for _, suffix := range m.Suffixes {
if f := FormatFromString(suffix); f != "" {
return f
}
}
return ""
}
// FormatFromContentString tries to detect the format (JSON, YAML or TOML)
// in the given string.
// It return an empty string if no format could be detected.
func (d Decoder) FormatFromContentString(data string) Format {
csvIdx := strings.IndexRune(data, d.Delimiter)
jsonIdx := strings.Index(data, "{")
yamlIdx := strings.Index(data, ":")
tomlIdx := strings.Index(data, "=")
if isLowerIndexThan(csvIdx, jsonIdx, yamlIdx, tomlIdx) {
return CSV
}
if isLowerIndexThan(jsonIdx, yamlIdx, tomlIdx) {
return JSON
}
if isLowerIndexThan(yamlIdx, tomlIdx) {
return YAML
}
if tomlIdx != -1 {
return TOML
}
return ""
}
func isLowerIndexThan(first int, others ...int) bool {
if first == -1 {
return false
}
for _, other := range others {
if other != -1 && other < first {
return false
}
}
return true
}