zeyn 0.0.5

Rust web framework for data heavy applications, written by AI agents and reviewed by people
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
140
141
142
143
144
145
146

//! Masked text: a pattern such as `(999) 999 99 99` or `aa99 9999 9999 9999 9999 9999 99` that
//! the input fills while the user types. Only the raw characters (`5321234567`) are submitted and
//! stored; the server checks them against the same pattern with the field's `mask` rule.
//!
//! | Pattern character | Means |
//! |---|---|
//! | `9` | a digit |
//! | `a` | a letter |
//! | `A` | a letter, written upper case |
//! | `*` | a letter or a digit |
//! | backslash | the next character is a literal |
//! | anything else | a literal, shown but not stored |

use super::controls::Slot;
use crate::render::escape;

/// One position of a mask pattern.
#[derive(Clone, Copy, PartialEq, Eq)]
enum Tok {
    Digit,
    Letter,
    Upper,
    Any,
    Lit(char),
}

fn tokens(pattern: &str) -> Vec<Tok> {
    let mut out = Vec::with_capacity(pattern.len());
    let mut escaped = false;
    for c in pattern.chars() {
        if escaped {
            out.push(Tok::Lit(c));
            escaped = false;
            continue;
        }
        out.push(match c {
            '\\' => {
                escaped = true;
                continue;
            }
            '9' => Tok::Digit,
            'a' => Tok::Letter,
            'A' => Tok::Upper,
            '*' => Tok::Any,
            c => Tok::Lit(c),
        });
    }
    out
}

impl Tok {
    fn takes(self, c: char) -> bool {
        match self {
            Tok::Digit => c.is_ascii_digit(),
            Tok::Letter => c.is_alphabetic(),
            Tok::Upper => c.is_alphabetic() && !c.is_lowercase(),
            Tok::Any => c.is_alphanumeric(),
            Tok::Lit(_) => false,
        }
    }
}

/// Whether `raw` fills every slot of `pattern` exactly, with no literals.
///
/// ```
/// use zeyn::ui::mask_fits;
/// assert!(mask_fits("(999) 999 99 99", "5321234567"));
/// assert!(!mask_fits("(999) 999 99 99", "(532) 123 45 67"));
/// assert!(!mask_fits("(999) 999 99 99", "532123"));
/// assert!(mask_fits("AA99", "TR33"));
/// assert!(!mask_fits("AA99", "tr33"));
/// ```
pub fn mask_fits(pattern: &str, raw: &str) -> bool {
    let mut slots = tokens(pattern).into_iter().filter(|t| !matches!(t, Tok::Lit(_)));
    let mut chars = raw.chars();
    loop {
        match (slots.next(), chars.next()) {
            (None, None) => return true,
            (Some(t), Some(c)) if t.takes(c) => {}
            _ => return false,
        }
    }
}

/// The raw characters of a value typed with or without the literals: `(532) 123 45 67` gives
/// `5321234567`, and letters in `A` slots become upper case. A value that does not follow the
/// pattern is returned as typed, so the `mask` rule reports it.
///
/// ```
/// use zeyn::ui::mask_raw;
/// assert_eq!(mask_raw("(999) 999 99 99", "(532) 123 45 67"), "5321234567");
/// assert_eq!(mask_raw("(999) 999 99 99", "5321234567"), "5321234567");
/// assert_eq!(mask_raw("AA99 9999", "tr33 0001"), "TR330001");
/// ```
pub fn mask_raw(pattern: &str, typed: &str) -> String {
    let toks = tokens(pattern);
    let mut raw = String::with_capacity(typed.len());
    let mut at = 0usize;
    'chars: for c in typed.trim().chars() {
        while let Some(Tok::Lit(l)) = toks.get(at) {
            at += 1;
            if *l == c {
                continue 'chars;
            }
        }
        match toks.get(at) {
            Some(Tok::Upper) if c.is_alphabetic() => raw.extend(c.to_uppercase()),
            Some(t) if t.takes(c) => raw.push(c),
            _ if !c.is_alphanumeric() => continue,
            _ => return typed.to_string(),
        }
        at += 1;
    }
    raw
}

/// The pattern as shown in messages and placeholders: every slot as `_`.
///
/// ```
/// use zeyn::ui::mask_example;
/// assert_eq!(mask_example("(999) 999 99 99"), "(___) ___ __ __");
/// ```
pub fn mask_example(pattern: &str) -> String {
    tokens(pattern).into_iter().map(|t| if let Tok::Lit(c) = t { c } else { '_' }).collect()
}

/// Writes a masked text input, always left to right (phone numbers, IBANs and codes read the same
/// way in every language): a plain text input holding the raw value (what the form submits
/// and what works without JavaScript) that the runtime shows through the pattern.
pub(crate) fn render_mask(out: &mut String, s: &Slot, pattern: &str) {
    let text = match s.value {
        crate::value::Value::Text(t) => t.as_str(),
        _ => "",
    };
    let numeric = tokens(pattern).iter().all(|t| matches!(t, Tok::Digit | Tok::Lit(_)));
    let example = mask_example(pattern);
    out.push_str(s.label);
    out.push_str(&format!(
        r#"<div class="z-mask" data-zeyn-mask="{}" data-example="{}"><input type="text" class="z-mask-value" dir="ltr" inputmode="{}" autocomplete="off" spellcheck="false" {} value="{}"></div>"#,
        escape(pattern),
        escape(&example),
        if numeric { "numeric" } else { "text" },
        s.common,
        escape(text)
    ));
}