yew_stdweb/html/listener/
mod.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
#[macro_use]
mod macros;

use cfg_if::cfg_if;
use cfg_match::cfg_match;

cfg_if! {
    if #[cfg(feature = "std_web")] {
        mod listener_stdweb;

        use stdweb::js;
        use stdweb::unstable::{TryFrom, TryInto};
        use stdweb::web::html_element::{InputElement, SelectElement, TextAreaElement};
        use stdweb::web::{Element, EventListenerHandle, FileList, IElement, INode};
        use stdweb::web::event::InputEvent;

        pub use listener_stdweb::*;
    } else if #[cfg(feature = "web_sys")] {
        mod listener_web_sys;

        use wasm_bindgen::JsCast;
        use web_sys::{
            Element, FileList, HtmlInputElement as InputElement, HtmlSelectElement as SelectElement,
            HtmlTextAreaElement as TextAreaElement,
            InputEvent
        };

        pub use listener_web_sys::*;
    }
}

/// A type representing data from `oninput` event.
#[derive(Debug)]
pub struct InputData {
    /// Inserted characters. Contains value from
    /// [InputEvent](https://developer.mozilla.org/en-US/docs/Web/API/InputEvent/data).
    pub value: String,
    /// The InputEvent received.
    pub event: InputEvent,
}

// There is no '.../Web/API/ChangeEvent/data' (for onchange) similar to
// https://developer.mozilla.org/en-US/docs/Web/API/InputEvent/data (for oninput).
// ChangeData actually contains the value of the InputElement/TextAreaElement
// after `change` event occured or contains the SelectElement (see more at the
// variant ChangeData::Select)

/// A type representing change of value(s) of an element after committed by user
/// ([onchange event](https://developer.mozilla.org/en-US/docs/Web/Events/change)).
#[derive(Debug)]
pub enum ChangeData {
    /// Value of the element in cases of `<input>`, `<textarea>`
    Value(String),
    /// SelectElement in case of `<select>` element. You can use one of methods of SelectElement
    /// to collect your required data such as: `value`, `selected_index`, `selected_indices` or
    /// `selected_values`. You can also iterate throught `selected_options` yourself.
    Select(SelectElement),
    /// Files
    Files(FileList),
}

fn oninput_handler(this: &Element, event: InputEvent) -> InputData {
    // Normally only InputElement or TextAreaElement can have an oninput event listener. In
    // practice though any element with `contenteditable=true` may generate such events,
    // therefore here we fall back to just returning the text content of the node.
    // See https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/input_event.
    let (v1, v2) = cfg_match! {
        feature = "std_web" => ({
            (
                this.clone()
                    .try_into()
                    .map(|input: InputElement| input.raw_value())
                    .ok(),
                this.clone()
                    .try_into()
                    .map(|input: TextAreaElement| input.value())
                    .ok(),
            )
        }),
        feature = "web_sys" => ({
            (
                this.dyn_ref().map(|input: &InputElement| input.value()),
                this.dyn_ref().map(|input: &TextAreaElement| input.value()),
            )
        }),
    };
    let v3 = this.text_content();
    let value = v1.or(v2).or(v3)
        .expect("only an InputElement or TextAreaElement or an element with contenteditable=true can have an oninput event listener");
    InputData { value, event }
}

fn onchange_handler(this: &Element) -> ChangeData {
    match this.node_name().as_ref() {
        "INPUT" => {
            let input = cfg_match! {
                feature = "std_web" => InputElement::try_from(this.clone()).unwrap(),
                feature = "web_sys" => this.dyn_ref::<InputElement>().unwrap(),
            };
            let is_file = input
                .get_attribute("type")
                .map(|value| value.eq_ignore_ascii_case("file"))
                .unwrap_or(false);
            if is_file {
                let files: FileList = cfg_match! {
                    feature = "std_web" => js!( return @{input}.files; ).try_into().unwrap(),
                    feature = "web_sys" => input.files().unwrap(),
                };
                ChangeData::Files(files)
            } else {
                cfg_match! {
                    feature = "std_web" => ChangeData::Value(input.raw_value()),
                    feature = "web_sys" => ChangeData::Value(input.value()),
                }
            }
        }
        "TEXTAREA" => {
            let tae = cfg_match! {
                feature = "std_web" => TextAreaElement::try_from(this.clone()).unwrap(),
                feature = "web_sys" => this.dyn_ref::<TextAreaElement>().unwrap(),
            };
            ChangeData::Value(tae.value())
        }
        "SELECT" => {
            let se = cfg_match! {
                feature = "std_web" => SelectElement::try_from(this.clone()).unwrap(),
                feature = "web_sys" => this.dyn_ref::<SelectElement>().unwrap().clone(),
            };
            ChangeData::Select(se)
        }
        _ => {
            panic!("only an InputElement, TextAreaElement or SelectElement can have an onchange event listener");
        }
    }
}

/// Handler to an event listener, only use is to cancel the event.
#[cfg(feature = "std_web")]
#[derive(Debug)]
pub struct EventListener(Option<EventListenerHandle>);

#[cfg(feature = "std_web")]
impl Drop for EventListener {
    fn drop(&mut self) {
        if let Some(event) = self.0.take() {
            event.remove()
        }
    }
}