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
|
package markdown
import (
"html/template"
"regexp"
"git.anhgelus.world/anhgelus/small-web/dom"
)
var ExternalLink = regexp.MustCompile(`https?://`)
type astLink struct {
content block
href block
addSpace bool
}
func (a *astLink) Eval(opt *Option) (template.HTML, *ParseError) {
content, err := a.content.Eval(opt)
if err != nil {
return "", err
}
href, err := a.href.Eval(opt)
if err != nil {
return "", err
}
rr := opt.RenderLink(string(content), string(href))
if a.addSpace {
return " " + rr, nil
}
return rr, nil
}
func RenderLink(content, href string) template.HTML {
anchor := dom.NewLiteralContentElement("a", template.HTML(content))
anchor.SetAttribute("href", href)
if ExternalLink.MatchString(href) {
anchor.SetAttribute("target", "_blank").SetAttribute("rel", "noreferer")
}
return anchor.Render()
}
type astImage struct {
alt block
src block
source []*astParagraph
}
func (a *astImage) Eval(opt *Option) (template.HTML, *ParseError) {
alt, err := a.alt.Eval(opt)
if err != nil {
return "", err
}
src, err := a.src.Eval(opt)
if err != nil {
return "", err
}
src = template.HTML(opt.ImageSource(string(src)))
img := dom.NewImg(src, alt)
figure := dom.NewContentElement("figure", []dom.Element{img})
if a.source == nil {
return figure.Render(), nil
}
var s template.HTML
for _, c := range a.source {
ct, err := c.Eval(opt)
if err != nil {
return "", err
}
s += ct + " "
}
s = s[:len(s)-1]
figcaption := dom.NewLiteralContentElement("figcaption", s)
figure.Contents = append(figure.Contents, figcaption)
return figure.Render(), nil
}
func external(lxs *lexers) (block, *ParseError) {
tp := lxs.Current().Value
if !lxs.Next() {
return astLiteral(tp), nil
}
lxs.Before() // because we called Next
addSpace := lxs.Before() && lxs.Current().Type == lexerBreak
lxs.Next() // because we called Before
var b block
var err *ParseError
switch tp {
case "![":
b, err = image(lxs)
case "[":
b, err = link(lxs, addSpace)
default:
b = astLiteral(tp)
}
return b, err
}
func link(lxs *lexers, addSpace bool) (block, *ParseError) {
lk := new(astLink)
lk.addSpace = addSpace
start := lxs.current
content, href, _, ok := parseExternal(lxs, false)
if !ok {
return reset(lxs, start), nil
}
lk.content = astLiteral(content)
lk.href = astLiteral(href)
return lk, nil
}
func image(lxs *lexers) (block, *ParseError) {
img := new(astImage)
start := lxs.current
alt, src, source, ok := parseExternal(lxs, true)
if !ok {
return reset(lxs, start), nil
}
img.alt = astLiteral(alt)
img.src = astLiteral(src)
img.source = source
return img, nil
}
func parseExternal(lxs *lexers, withSource bool) (string, string, []*astParagraph, bool) {
next := false
var s string
var first string
var end string
var ps []*astParagraph
n := 0
fn := func() bool {
p, err := paragraph(lxs, true)
if err != nil {
return false
}
ps = append(ps, p)
n = 0
return true
}
for lxs.Next() && n < 2 {
switch lxs.Current().Type {
case lexerBreak:
if !withSource {
return "", "", nil, false
}
n += len(lxs.Current().Value)
if n < 2 && first != "" && end != "" {
if !lxs.Next() {
return first, end, ps, true
}
ok := fn()
if !ok {
return "", "", nil, false
}
}
lxs.Before() // because we must parse lexerBreak and the next call must parse the next value
case lexerExternal:
if first != "" && end != "" {
return "", "", nil, false
}
if n > 0 && (first == "" || end == "") {
return "", "", nil, false
}
n = 0
if !next {
if lxs.Current().Value != "](" || !lxs.Next() {
return "", "", nil, false
}
lxs.Before() // because we called Next
first = s
s = ""
next = true
} else {
if lxs.Current().Value != ")" {
return "", "", nil, false
}
if !withSource {
return first, s, nil, true
}
end = s
s = ""
if lxs.Next() && lxs.Current().Type != lexerBreak {
return "", "", nil, false
}
lxs.Before() // because we called Next
}
default:
if ps != nil {
return "", "", nil, false
}
n = 0
s += lxs.Current().Value
}
}
if !withSource {
return "", "", nil, false
}
return first, end, ps, true
}
func reset(lxs *lexers, start int) block {
lxs.current = start
return astLiteral(lxs.Current().Value)
}
|
