rs-rich 0.0.2

A faithful Rust port of the Python `rich` terminal-rendering library
Documentation 
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

//! Exporting rendered output to HTML.
//!
//! Port of `rich/console.py`'s `export_html` + the `_export_format.py` template.
//! Turns a recorded stream of [`Segment`]s (captured via
//! [`Console::export_html`](crate::console::Console::export_html)) into a
//! self-contained HTML document, using a [`TerminalTheme`] to resolve colors.
//!
//! Scope: `inline_styles` (each span carries its own `style="…"`). The CSS-class
//! variant is a follow-up (see docs/DIVERGENCES.md).

use crate::segment::Segment;
use crate::terminal_theme::TerminalTheme;

/// The HTML document template. Port of `_export_format.CONSOLE_HTML_FORMAT`
/// (placeholders are substituted, not `format!`-ed, to avoid brace escaping).
const CONSOLE_HTML_FORMAT: &str = r#"<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<style>
{stylesheet}
body {
    color: {foreground};
    background-color: {background};
}
</style>
</head>
<body>
    <pre style="font-family:Menlo,'DejaVu Sans Mono',consolas,'Courier New',monospace"><code style="font-family:inherit">{code}</code></pre>
</body>
</html>
"#;

/// HTML-escape `text` (matching Python's `html.escape`, `quote=True`).
fn escape(text: &str) -> String {
    text.replace('&', "&amp;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
        .replace('\'', "&#x27;")
}

/// Substitute the four template placeholders. Port of the `.format(...)` call
/// (done via `replace` to avoid escaping the CSS braces).
fn fill_template(code: &str, stylesheet: &str, theme: &TerminalTheme) -> String {
    CONSOLE_HTML_FORMAT
        .replace("{stylesheet}", stylesheet)
        .replace("{foreground}", &theme.foreground.hex())
        .replace("{background}", &theme.background.hex())
        .replace("{code}", code)
}

/// Render `segments` to a self-contained HTML document with inline styles.
/// Port of `Console.export_html(inline_styles=True)`.
pub fn export_html_inline(segments: &[Segment], theme: &TerminalTheme) -> String {
    let simplified = Segment::simplify(segments);
    let mut code = String::new();
    for segment in &simplified {
        if segment.control {
            continue;
        }
        let text = escape(&segment.text);
        match &segment.style {
            Some(style) if !style.is_null() => {
                let rule = style.get_html_style(theme);
                if rule.is_empty() {
                    code.push_str(&text);
                } else {
                    code.push_str(&format!("<span style=\"{rule}\">{text}</span>"));
                }
            }
            _ => code.push_str(&text),
        }
    }
    fill_template(&code, "", theme)
}

/// Render `segments` to a self-contained HTML document using CSS classes and a
/// generated stylesheet. Port of `Console.export_html(inline_styles=False)`
/// (upstream's default). Distinct styles are numbered `.r1`, `.r2`, … in the
/// order first seen.
pub fn export_html_classes(segments: &[Segment], theme: &TerminalTheme) -> String {
    let simplified = Segment::simplify(segments);
    // (rule → class number), in insertion order.
    let mut styles: Vec<(String, usize)> = Vec::new();
    let mut code = String::new();
    for segment in &simplified {
        if segment.control {
            continue;
        }
        let text = escape(&segment.text);
        match &segment.style {
            Some(style) if !style.is_null() => {
                let rule = style.get_html_style(theme);
                if rule.is_empty() {
                    code.push_str(&text);
                } else {
                    let number = match styles.iter().find(|(existing, _)| *existing == rule) {
                        Some((_, n)) => *n,
                        None => {
                            let n = styles.len() + 1;
                            styles.push((rule, n));
                            n
                        }
                    };
                    code.push_str(&format!("<span class=\"r{number}\">{text}</span>"));
                }
            }
            _ => code.push_str(&text),
        }
    }
    let stylesheet = styles
        .iter()
        .map(|(rule, number)| format!(".r{number} {{{rule}}}"))
        .collect::<Vec<_>>()
        .join("\n");
    fill_template(&code, &stylesheet, theme)
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::style::Style;

    #[test]
    fn escapes_html_special_chars() {
        assert_eq!(escape("a<b>&\"'c"), "a&lt;b&gt;&amp;&quot;&#x27;c");
    }

    #[test]
    fn bold_red_html_style() {
        // Captured from real rich 15.0.0 Style.get_html_style(DEFAULT_TERMINAL_THEME).
        let style = Style::parse("bold red").unwrap();
        assert_eq!(
            style.get_html_style(&crate::terminal_theme::DEFAULT_TERMINAL_THEME),
            "color: #800000; text-decoration-color: #800000; font-weight: bold"
        );
    }
}