summaryrefslogtreecommitdiffstats
path: root/vendor/html5ever/src/serialize/mod.rs
blob: 3a57b477ef544ee1bc8d3cf269c8d4f57c558fc8 (plain)
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
// Copyright 2014-2017 The html5ever Project Developers. See the
// COPYRIGHT file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use log::warn;
pub use markup5ever::serialize::{AttrRef, Serialize, Serializer, TraversalScope};
use markup5ever::{local_name, namespace_url, ns};
use std::default::Default;
use std::io::{self, Write};

use crate::{LocalName, QualName};

pub fn serialize<Wr, T>(writer: Wr, node: &T, opts: SerializeOpts) -> io::Result<()>
where
    Wr: Write,
    T: Serialize,
{
    let mut ser = HtmlSerializer::new(writer, opts.clone());
    node.serialize(&mut ser, opts.traversal_scope)
}

#[derive(Clone)]
pub struct SerializeOpts {
    /// Is scripting enabled?
    pub scripting_enabled: bool,

    /// Serialize the root node? Default: ChildrenOnly
    pub traversal_scope: TraversalScope,

    /// If the serializer is asked to serialize an invalid tree, the default
    /// behavior is to panic in the event that an `end_elem` is created without a
    /// matching `start_elem`. Setting this to true will prevent those panics by
    /// creating a default parent on the element stack. No extra start elem will
    /// actually be written. Default: false
    pub create_missing_parent: bool,
}

impl Default for SerializeOpts {
    fn default() -> SerializeOpts {
        SerializeOpts {
            scripting_enabled: true,
            traversal_scope: TraversalScope::ChildrenOnly(None),
            create_missing_parent: false,
        }
    }
}

#[derive(Default)]
struct ElemInfo {
    html_name: Option<LocalName>,
    ignore_children: bool
}

pub struct HtmlSerializer<Wr: Write> {
    pub writer: Wr,
    opts: SerializeOpts,
    stack: Vec<ElemInfo>,
}

fn tagname(name: &QualName) -> LocalName {
    match name.ns {
        ns!(html) | ns!(mathml) | ns!(svg) => (),
        ref ns => {
            // FIXME(#122)
            warn!("node with weird namespace {:?}", ns);
        },
    }

    name.local.clone()
}

impl<Wr: Write> HtmlSerializer<Wr> {
    pub fn new(writer: Wr, opts: SerializeOpts) -> Self {
        let html_name = match opts.traversal_scope {
            TraversalScope::IncludeNode | TraversalScope::ChildrenOnly(None) => None,
            TraversalScope::ChildrenOnly(Some(ref n)) => Some(tagname(n)),
        };
        HtmlSerializer {
            writer,
            opts,
            stack: vec![ElemInfo {
                html_name,
                ignore_children: false,
            }],
        }
    }

    fn parent(&mut self) -> &mut ElemInfo {
        if self.stack.is_empty() {
            if self.opts.create_missing_parent {
                warn!("ElemInfo stack empty, creating new parent");
                self.stack.push(Default::default());
            } else {
                panic!("no parent ElemInfo")
            }
        }
        self.stack.last_mut().unwrap()
    }

    fn write_escaped(&mut self, text: &str, attr_mode: bool) -> io::Result<()> {
        for c in text.chars() {
            match c {
                '&' => self.writer.write_all(b"&amp;"),
                '\u{00A0}' => self.writer.write_all(b"&nbsp;"),
                '"' if attr_mode => self.writer.write_all(b"&quot;"),
                '<' if !attr_mode => self.writer.write_all(b"&lt;"),
                '>' if !attr_mode => self.writer.write_all(b"&gt;"),
                c => self.writer.write_fmt(format_args!("{}", c)),
            }?;
        }
        Ok(())
    }
}

impl<Wr: Write> Serializer for HtmlSerializer<Wr> {
    fn start_elem<'a, AttrIter>(&mut self, name: QualName, attrs: AttrIter) -> io::Result<()>
    where
        AttrIter: Iterator<Item = AttrRef<'a>>,
    {
        let html_name = match name.ns {
            ns!(html) => Some(name.local.clone()),
            _ => None,
        };

        if self.parent().ignore_children {
            self.stack.push(ElemInfo {
                html_name,
                ignore_children: true,
            });
            return Ok(());
        }

        self.writer.write_all(b"<")?;
        self.writer.write_all(tagname(&name).as_bytes())?;
        for (name, value) in attrs {
            self.writer.write_all(b" ")?;

            match name.ns {
                ns!() => (),
                ns!(xml) => self.writer.write_all(b"xml:")?,
                ns!(xmlns) => {
                    if name.local != local_name!("xmlns") {
                        self.writer.write_all(b"xmlns:")?;
                    }
                },
                ns!(xlink) => self.writer.write_all(b"xlink:")?,
                ref ns => {
                    // FIXME(#122)
                    warn!("attr with weird namespace {:?}", ns);
                    self.writer.write_all(b"unknown_namespace:")?;
                },
            }

            self.writer.write_all(name.local.as_bytes())?;
            self.writer.write_all(b"=\"")?;
            self.write_escaped(value, true)?;
            self.writer.write_all(b"\"")?;
        }
        self.writer.write_all(b">")?;

        let ignore_children = name.ns == ns!(html) &&
            match name.local {
                local_name!("area") |
                local_name!("base") |
                local_name!("basefont") |
                local_name!("bgsound") |
                local_name!("br") |
                local_name!("col") |
                local_name!("embed") |
                local_name!("frame") |
                local_name!("hr") |
                local_name!("img") |
                local_name!("input") |
                local_name!("keygen") |
                local_name!("link") |
                local_name!("meta") |
                local_name!("param") |
                local_name!("source") |
                local_name!("track") |
                local_name!("wbr") => true,
                _ => false,
            };

        self.stack.push(ElemInfo {
            html_name,
            ignore_children,
        });

        Ok(())
    }

    fn end_elem(&mut self, name: QualName) -> io::Result<()> {
        let info = match self.stack.pop() {
            Some(info) => info,
            None if self.opts.create_missing_parent => {
                warn!("missing ElemInfo, creating default.");
                Default::default()
            },
            _ => panic!("no ElemInfo"),
        };
        if info.ignore_children {
            return Ok(());
        }

        self.writer.write_all(b"</")?;
        self.writer.write_all(tagname(&name).as_bytes())?;
        self.writer.write_all(b">")
    }

    fn write_text(&mut self, text: &str) -> io::Result<()> {
        let escape = match self.parent().html_name {
            Some(local_name!("style")) |
            Some(local_name!("script")) |
            Some(local_name!("xmp")) |
            Some(local_name!("iframe")) |
            Some(local_name!("noembed")) |
            Some(local_name!("noframes")) |
            Some(local_name!("plaintext")) => false,

            Some(local_name!("noscript")) => !self.opts.scripting_enabled,

            _ => true,
        };

        if escape {
            self.write_escaped(text, false)
        } else {
            self.writer.write_all(text.as_bytes())
        }
    }

    fn write_comment(&mut self, text: &str) -> io::Result<()> {
        self.writer.write_all(b"<!--")?;
        self.writer.write_all(text.as_bytes())?;
        self.writer.write_all(b"-->")
    }

    fn write_doctype(&mut self, name: &str) -> io::Result<()> {
        self.writer.write_all(b"<!DOCTYPE ")?;
        self.writer.write_all(name.as_bytes())?;
        self.writer.write_all(b">")
    }

    fn write_processing_instruction(&mut self, target: &str, data: &str) -> io::Result<()> {
        self.writer.write_all(b"<?")?;
        self.writer.write_all(target.as_bytes())?;
        self.writer.write_all(b" ")?;
        self.writer.write_all(data.as_bytes())?;
        self.writer.write_all(b">")
    }
}