script/dom/
htmlmetaelement.rs

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
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

use dom_struct::dom_struct;
use html5ever::{LocalName, Prefix, local_name, namespace_url, ns};
use js::rust::HandleObject;
use style::str::HTML_SPACE_CHARACTERS;

use crate::dom::attr::Attr;
use crate::dom::bindings::codegen::Bindings::HTMLMetaElementBinding::HTMLMetaElementMethods;
use crate::dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
use crate::dom::bindings::inheritance::Castable;
use crate::dom::bindings::root::DomRoot;
use crate::dom::bindings::str::DOMString;
use crate::dom::document::{Document, determine_policy_for_token};
use crate::dom::element::{AttributeMutation, Element};
use crate::dom::htmlelement::HTMLElement;
use crate::dom::htmlheadelement::HTMLHeadElement;
use crate::dom::node::{BindContext, Node, NodeTraits, UnbindContext};
use crate::dom::virtualmethods::VirtualMethods;
use crate::script_runtime::CanGc;

#[dom_struct]
pub(crate) struct HTMLMetaElement {
    htmlelement: HTMLElement,
}

impl HTMLMetaElement {
    fn new_inherited(
        local_name: LocalName,
        prefix: Option<Prefix>,
        document: &Document,
    ) -> HTMLMetaElement {
        HTMLMetaElement {
            htmlelement: HTMLElement::new_inherited(local_name, prefix, document),
        }
    }

    #[cfg_attr(crown, allow(crown::unrooted_must_root))]
    pub(crate) fn new(
        local_name: LocalName,
        prefix: Option<Prefix>,
        document: &Document,
        proto: Option<HandleObject>,
        can_gc: CanGc,
    ) -> DomRoot<HTMLMetaElement> {
        Node::reflect_node_with_proto(
            Box::new(HTMLMetaElement::new_inherited(local_name, prefix, document)),
            document,
            proto,
            can_gc,
        )
    }

    fn process_attributes(&self) {
        let element = self.upcast::<Element>();
        if let Some(ref name) = element.get_name() {
            let name = name.to_ascii_lowercase();
            let name = name.trim_matches(HTML_SPACE_CHARACTERS);
            if name == "referrer" {
                self.apply_referrer();
            }
        // https://html.spec.whatwg.org/multipage/#attr-meta-http-equiv
        } else if !self.HttpEquiv().is_empty() {
            // TODO: Implement additional http-equiv candidates
            match self.HttpEquiv().to_ascii_lowercase().as_str() {
                "refresh" => self.declarative_refresh(),
                "content-security-policy" => self.apply_csp_list(),
                _ => {},
            }
        }
    }

    fn process_referrer_attribute(&self) {
        let element = self.upcast::<Element>();
        if let Some(ref name) = element.get_name() {
            let name = name.to_ascii_lowercase();
            let name = name.trim_matches(HTML_SPACE_CHARACTERS);

            if name == "referrer" {
                self.apply_referrer();
            }
        }
    }

    /// <https://html.spec.whatwg.org/multipage/#meta-referrer>
    fn apply_referrer(&self) {
        let doc = self.owner_document();
        // From spec: For historical reasons, unlike other standard metadata names, the processing model for referrer
        // is not responsive to element removals, and does not use tree order. Only the most-recently-inserted or
        // most-recently-modified meta element in this state has an effect.
        // 1. If element is not in a document tree, then return.
        let meta_node = self.upcast::<Node>();
        if !meta_node.is_in_a_document_tree() {
            return;
        }

        // 2. If element does not have a name attribute whose value is an ASCII case-insensitive match for "referrer",
        // then return.
        if self.upcast::<Element>().get_name() != Some(atom!("referrer")) {
            return;
        }

        // 3. If element does not have a content attribute, or that attribute's value is the empty string, then return.
        let content = self
            .upcast::<Element>()
            .get_attribute(&ns!(), &local_name!("content"));
        if let Some(attr) = content {
            let attr = attr.value();
            let attr_val = attr.trim();
            if !attr_val.is_empty() {
                doc.set_referrer_policy(determine_policy_for_token(attr_val));
            }
        }
    }

    /// <https://html.spec.whatwg.org/multipage/#attr-meta-http-equiv-content-security-policy>
    fn apply_csp_list(&self) {
        if let Some(parent) = self.upcast::<Node>().GetParentElement() {
            if let Some(head) = parent.downcast::<HTMLHeadElement>() {
                head.set_content_security_policy();
            }
        }
    }

    /// <https://html.spec.whatwg.org/multipage/#shared-declarative-refresh-steps>
    fn declarative_refresh(&self) {
        if !self.upcast::<Node>().is_in_a_document_tree() {
            return;
        }

        // 2
        let content = self.Content();
        // 1
        if !content.is_empty() {
            // 3
            self.owner_document()
                .shared_declarative_refresh_steps(content.as_bytes());
        }
    }
}

impl HTMLMetaElementMethods<crate::DomTypeHolder> for HTMLMetaElement {
    // https://html.spec.whatwg.org/multipage/#dom-meta-name
    make_getter!(Name, "name");

    // https://html.spec.whatwg.org/multipage/#dom-meta-name
    make_atomic_setter!(SetName, "name");

    // https://html.spec.whatwg.org/multipage/#dom-meta-content
    make_getter!(Content, "content");

    // https://html.spec.whatwg.org/multipage/#dom-meta-content
    make_setter!(SetContent, "content");

    // https://html.spec.whatwg.org/multipage/#dom-meta-httpequiv
    make_getter!(HttpEquiv, "http-equiv");
    // https://html.spec.whatwg.org/multipage/#dom-meta-httpequiv
    make_atomic_setter!(SetHttpEquiv, "http-equiv");

    // https://html.spec.whatwg.org/multipage/#dom-meta-scheme
    make_getter!(Scheme, "scheme");
    // https://html.spec.whatwg.org/multipage/#dom-meta-scheme
    make_setter!(SetScheme, "scheme");
}

impl VirtualMethods for HTMLMetaElement {
    fn super_type(&self) -> Option<&dyn VirtualMethods> {
        Some(self.upcast::<HTMLElement>() as &dyn VirtualMethods)
    }

    fn bind_to_tree(&self, context: &BindContext, can_gc: CanGc) {
        if let Some(s) = self.super_type() {
            s.bind_to_tree(context, can_gc);
        }

        if context.tree_connected {
            self.process_attributes();
        }
    }

    fn attribute_mutated(&self, attr: &Attr, mutation: AttributeMutation, can_gc: CanGc) {
        if let Some(s) = self.super_type() {
            s.attribute_mutated(attr, mutation, can_gc);
        }

        self.process_referrer_attribute();
    }

    fn unbind_from_tree(&self, context: &UnbindContext, can_gc: CanGc) {
        if let Some(s) = self.super_type() {
            s.unbind_from_tree(context, can_gc);
        }

        if context.tree_connected {
            self.process_referrer_attribute();
        }
    }
}