This repository has been archived by the owner on Nov 16, 2021. It is now read-only.
/
page.go
335 lines (289 loc) · 8.08 KB
/
page.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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
// Copyright 2014 Daniel Kertesz <daniel@spatof.org>
// All rights reserved. This program comes with ABSOLUTELY NO WARRANTY.
// See the file LICENSE for details.
package spock
import (
"bytes"
"errors"
"fmt"
"github.com/mschoch/blackfriday-text"
"github.com/russross/blackfriday"
"gopkg.in/yaml.v1"
"io/ioutil"
"log"
"os"
"os/exec"
"path/filepath"
"time"
)
// NewPageContent is the initial content of a new Wiki page.
var NewPageContent = `---
title: "My page"
description: "A brief page description..."
language: "en"
---
# My document title
My first paragraph.
`
const (
markdownName = "markdown"
rstName = "rst"
orgName = "org"
DefaultExtension = "md"
)
const (
PANDOC_IN_ORG uint8 = iota + 1
PANDOC_IN_RST
PANDOC_OUT_HTML
PANDOC_OUT_TXT
)
var (
htmlBodyStart = []byte("<body>")
htmlBodyEnd = []byte("</body>")
headerTag = []byte("---")
pandocEnabled bool = false
pandocExe = ""
)
func init() {
var err error
if pandocExe, err = exec.LookPath("pandoc"); err == nil {
pandocEnabled = true
} else {
log.Printf("Cannot find pandoc, disabling extra renderers\n")
}
}
// PageHeader is the optional YAML header of a wiki page.
type PageHeader struct {
Title string
Description string
Language string
Markup string
}
// Page is a wiki page. The Path attribute contains the relative path
// to the file containing the wiki page (e.g. docs/programming/python.md).
type Page struct {
Path string
Header *PageHeader
RawBytes []byte
Content []byte
Mtime time.Time
}
// NewPage is the preferred way to create new Page objects.
func NewPage(path string) *Page {
pageHdr := &PageHeader{}
page := &Page{Path: path, Header: pageHdr}
return page
}
func ParsePageBytes(data []byte) (*PageHeader, []byte, error) {
var content []byte
ph := &PageHeader{}
// if the first bytes does not contain the YAML header
if !bytes.Equal(data[0:len(headerTag)], headerTag) {
return ph, data, nil
} else {
// read and parse the YAML header
var header []byte
// find the second yaml marker "---": we skip the first 3 bytes as we need to find
// the *second* row of "---"; after we have found the position we add back the 3
// bytes, to account for the first "---". Clear uh?
mark := bytes.Index(data[len(headerTag):], headerTag)
if mark == -1 {
return nil, content, errors.New("Cannot find the closing YAML marker")
}
mark += len(headerTag)
// cross-platform way to find the end of the line
eolMark := bytes.Index(data[mark:], []byte("\n"))
if eolMark == -1 {
return nil, content, errors.New("Cannot find the second newline character")
}
headerEnd := mark + eolMark
header = data[0:headerEnd]
content = data[headerEnd:]
err := yaml.Unmarshal(header, ph)
if err != nil {
return nil, content, err
}
}
return ph, content, nil
}
// LoadPage loads a page from the filesystem; the "path" argument must be an
// absolute filename, and the "relpath" must be relative "wiki path" plus
// the file extension; example arguments:
// "/var/spock/repository/notes/Linux.md" and "notes/Linux.md".
func LoadPage(path, relpath string) (*Page, error) {
if !filepath.IsAbs(path) {
return nil, fmt.Errorf("page path %s is not an absolute path", path)
}
file, err := os.Open(path)
if err != nil {
return nil, err
}
fi, err := file.Stat()
if err != nil {
return nil, err
}
data, err := ioutil.ReadAll(file)
if err != nil {
return nil, err
}
page := NewPage(relpath)
if err := page.SetRawBytes(data); err != nil {
return nil, err
}
page.Mtime = fi.ModTime()
return page, nil
}
func (page *Page) SetRawBytes(content []byte) (err error) {
page.RawBytes = content
page.Header, page.Content, err = ParsePageBytes(page.RawBytes)
if err == nil {
page.Mtime = time.Now()
}
return err
}
// ShortenPageName returns the filename without the extension.
func ShortenPageName(name string) string {
if ext := filepath.Ext(name); len(ext) > 0 {
l := len(name) - len(ext)
return name[0:l]
}
return name
}
// ShortName is the "short" (i.e. without the filename extension) name of a page.
func (page *Page) ShortName() string {
return ShortenPageName(page.Path)
}
func (page *Page) String() string {
return fmt.Sprintf("Page[%s]", page.Path)
}
// GetMarkup return the page markup based on header informations or filename extension.
func (page *Page) GetMarkup() (markup string) {
if page.Header.Markup != "" {
markup = page.Header.Markup
} else {
ext := filepath.Ext(page.Path)
switch ext {
case ".md", ".txt":
markup = markdownName
case ".rst":
markup = rstName
case ".org":
markup = orgName
default:
markup = markdownName // XXX default
}
}
return
}
// Render renders the HTML version of a Wiki page.
func (page *Page) Render() (html []byte, err error) {
markup := page.GetMarkup()
switch markup {
case markdownName:
html, err = renderMarkdown(page.Content)
case rstName:
html, err = renderRst(page.Content)
case orgName:
html, err = renderOrg(page.Content)
default:
html, err = []byte(page.Content), fmt.Errorf("Unknown format: %s", markup)
}
return html, err
}
func (page *Page) RenderPlaintext() (txt []byte, err error) {
switch page.GetMarkup() {
case markdownName:
extensions := 0
renderer := blackfridaytext.TextRenderer()
txt, err = blackfriday.Markdown(page.Content, renderer, extensions), nil
case rstName:
txt, err = renderRstPlain(page.Content)
case orgName:
txt, err = renderOrgPlain(page.Content)
default:
// we won't return an error because text rendering is "best effort" :)
txt, err = page.RawBytes, nil
}
return txt, err
}
func (page *Page) RenderPreview(content []byte) (html []byte, err error) {
markup := page.GetMarkup()
switch markup {
case markdownName:
html, err = renderMarkdown(content)
case rstName:
html, err = renderRst(content)
case orgName:
html, err = renderOrg(content)
default:
html, err = []byte(content), fmt.Errorf("Unknown format: %s", markup)
}
return html, err
}
func renderMarkdown(content []byte) ([]byte, error) {
// Add TOC to the HTML output
htmlFlags := 0
htmlFlags |= blackfriday.HTML_TOC
htmlFlags |= blackfriday.HTML_FOOTNOTE_RETURN_LINKS
renderer := blackfriday.HtmlRenderer(htmlFlags, "", "")
extensions := 0
extensions |= blackfriday.EXTENSION_NO_INTRA_EMPHASIS
extensions |= blackfriday.EXTENSION_TABLES
extensions |= blackfriday.EXTENSION_FENCED_CODE
extensions |= blackfriday.EXTENSION_AUTOLINK
extensions |= blackfriday.EXTENSION_STRIKETHROUGH
extensions |= blackfriday.EXTENSION_SPACE_HEADERS
return blackfriday.Markdown(content, renderer, extensions), nil
}
func renderPandoc(content []byte, srcType uint8, dstType uint8, extraArgs ...string) ([]byte, error) {
if !pandocEnabled {
return nil, errors.New("pandoc executable was not found in PATH")
}
var inType string = ""
switch {
case srcType == PANDOC_IN_ORG:
inType = "org"
case srcType == PANDOC_IN_RST:
inType = "rst"
}
if inType == "" {
return nil, fmt.Errorf("Unknown input type: %d", srcType)
}
var outType string = ""
switch {
case dstType == PANDOC_OUT_HTML:
outType = "html"
case dstType == PANDOC_OUT_TXT:
outType = "plain"
}
if outType == "" {
return nil, fmt.Errorf("Unknown output type: %d", dstType)
}
cmdline := []string{"-f", inType, "-t", outType}
cmdline = append(cmdline, extraArgs...)
cmd := exec.Command(pandocExe, cmdline...)
cmd.Stdin = bytes.NewReader(content)
var out, errout bytes.Buffer
cmd.Stdout = &out
cmd.Stderr = &errout
if err := cmd.Run(); err != nil {
return nil, fmt.Errorf("Error executing pandoc renderer: %s", err.Error())
}
errStr := errout.String()
if len(errStr) > 0 {
log.Printf("WARNING: stderr from pandoc: %s\n", errStr)
}
return out.Bytes(), nil
}
func renderRst(content []byte) ([]byte, error) {
return renderPandoc(content, PANDOC_IN_RST, PANDOC_OUT_HTML)
}
func renderOrg(content []byte) ([]byte, error) {
return renderPandoc(content, PANDOC_IN_ORG, PANDOC_OUT_HTML)
}
func renderRstPlain(content []byte) ([]byte, error) {
return renderPandoc(content, PANDOC_IN_RST, PANDOC_OUT_TXT)
}
func renderOrgPlain(content []byte) ([]byte, error) {
return renderPandoc(content, PANDOC_IN_ORG, PANDOC_OUT_TXT)
}