forked from journeymidnight/yig-front-caddy
/
metadata.go
160 lines (135 loc) · 3.39 KB
/
metadata.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
// Copyright 2015 Light Code Labs, LLC
//
// 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 metadata
import (
"bufio"
"bytes"
"time"
)
var (
// Date format YYYY-MM-DD HH:MM:SS or YYYY-MM-DD
timeLayout = []string{
`2006-01-02 15:04:05-0700`,
`2006-01-02 15:04:05`,
`2006-01-02`,
}
)
// Metadata stores a page's metadata
type Metadata struct {
// Page title
Title string
// Page template
Template string
// Publish date
Date time.Time
// Variables to be used with Template
Variables map[string]interface{}
}
// NewMetadata returns a new Metadata struct, loaded with the given map
func NewMetadata(parsedMap map[string]interface{}) Metadata {
md := Metadata{
Variables: make(map[string]interface{}),
}
md.load(parsedMap)
return md
}
// load loads parsed values in parsedMap into Metadata
func (m *Metadata) load(parsedMap map[string]interface{}) {
// Pull top level things out
if title, ok := parsedMap["title"]; ok {
m.Title, _ = title.(string)
}
if template, ok := parsedMap["template"]; ok {
m.Template, _ = template.(string)
}
if date, ok := parsedMap["date"].(string); ok {
for _, layout := range timeLayout {
if t, err := time.Parse(layout, date); err == nil {
m.Date = t
break
}
}
}
m.Variables = parsedMap
}
// Parser is a an interface that must be satisfied by each parser
type Parser interface {
// Initialize a parser
Init(b *bytes.Buffer) bool
// Type of metadata
Type() string
// Parsed metadata.
Metadata() Metadata
// Raw markdown.
Markdown() []byte
}
// GetParser returns a parser for the given data
func GetParser(buf []byte) Parser {
for _, p := range parsers() {
b := bytes.NewBuffer(buf)
if p.Init(b) {
return p
}
}
return nil
}
// parsers returns all available parsers
func parsers() []Parser {
return []Parser{
&TOMLParser{},
&YAMLParser{},
&JSONParser{},
// This one must be last
&NoneParser{},
}
}
// Split out prefixed/suffixed metadata with given delimiter
func splitBuffer(b *bytes.Buffer, delim string) (*bytes.Buffer, *bytes.Buffer) {
scanner := bufio.NewScanner(b)
// Read and check first line
if !scanner.Scan() {
return nil, nil
}
if string(bytes.TrimSpace(scanner.Bytes())) != delim {
return nil, nil
}
// Accumulate metadata, until delimiter
meta := bytes.NewBuffer(nil)
for scanner.Scan() {
if string(bytes.TrimSpace(scanner.Bytes())) == delim {
break
}
if _, err := meta.Write(scanner.Bytes()); err != nil {
return nil, nil
}
if _, err := meta.WriteRune('\n'); err != nil {
return nil, nil
}
}
// Make sure we saw closing delimiter
if string(bytes.TrimSpace(scanner.Bytes())) != delim {
return nil, nil
}
// The rest is markdown
markdown := new(bytes.Buffer)
for scanner.Scan() {
if _, err := markdown.Write(scanner.Bytes()); err != nil {
return nil, nil
}
if _, err := markdown.WriteRune('\n'); err != nil {
return nil, nil
}
}
return meta, markdown
}