toasty_core/schema/app/
constraint.rs

1mod length;
2pub use length::ConstraintLength;
3
4use crate::{Result, stmt};
5
6/// A validation constraint applied to a field.
7///
8/// Constraints are checked at the application level before values are persisted
9/// to the database. If a constraint check fails, the operation returns an error
10/// instead of sending the value to the driver.
11///
12/// # Examples
13///
14/// ```
15/// use toasty_core::schema::app::Constraint;
16///
17/// let c = Constraint::length_less_than(255);
18/// // The constraint can be checked against field values at runtime.
19/// ```
20#[derive(Debug, Clone)]
21pub enum Constraint {
22    /// A length constraint on a string field.
23    Length(ConstraintLength),
24}
25
26impl Constraint {
27    /// Creates a length constraint requiring the value to be shorter than `max`
28    /// characters.
29    ///
30    /// # Examples
31    ///
32    /// ```
33    /// use toasty_core::schema::app::Constraint;
34    ///
35    /// let c = Constraint::length_less_than(100);
36    /// ```
37    pub fn length_less_than(max: u64) -> Self {
38        ConstraintLength {
39            min: None,
40            max: Some(max),
41        }
42        .into()
43    }
44
45    /// Validates `expr` against this constraint.
46    ///
47    /// Returns `Ok(())` if the value satisfies the constraint, or an error
48    /// describing the violation.
49    pub fn check(&self, expr: &stmt::Entry<'_>) -> Result<()> {
50        match self {
51            Constraint::Length(length) => length.check(expr),
52        }
53    }
54}
toasty_core/schema/app/constraint.rs

toasty_core/schema/app/
constraint.rs
