toasty_core/schema/app/relation/
has_many.rs

1use crate::{
2    schema::app::{BelongsTo, FieldId, Model, ModelId, Name, Schema},
3    stmt,
4};
5
6/// The inverse side of a one-to-many relationship.
7///
8/// A `HasMany` field on model A means "A has many Bs". The actual foreign key
9/// lives on model B as a [`BelongsTo`] field pointing back at A. The two
10/// sides are linked via the [`pair`](HasMany::pair) field.
11///
12/// # Examples
13///
14/// ```ignore
15/// // Given a `User` model that has many `Post`s:
16/// let has_many: &HasMany = user_field.ty.as_has_many_unwrap();
17/// let post_model = has_many.target(&schema);
18/// let inverse = has_many.pair(&schema); // the BelongsTo on Post
19/// ```
20#[derive(Debug, Clone)]
21pub struct HasMany {
22    /// The [`ModelId`] of the associated (target) model.
23    pub target: ModelId,
24
25    /// The expression type this field evaluates to from the application's
26    /// perspective.
27    pub expr_ty: stmt::Type,
28
29    /// The singular name for one associated item (used in generated method
30    /// names).
31    pub singular: Name,
32
33    /// The [`BelongsTo`] field on the target model that pairs with this
34    /// relation.
35    pub pair: FieldId,
36}
37
38impl HasMany {
39    /// Resolves the target [`Model`] from the given schema.
40    pub fn target<'a>(&self, schema: &'a Schema) -> &'a Model {
41        schema.model(self.target)
42    }
43
44    /// Resolves the paired [`BelongsTo`] relation on the target model.
45    ///
46    /// # Panics
47    ///
48    /// Panics if the paired field is not a `BelongsTo` variant.
49    pub fn pair<'a>(&self, schema: &'a Schema) -> &'a BelongsTo {
50        schema.field(self.pair).ty.as_belongs_to_unwrap()
51    }
52}
toasty_core/schema/app/relation/has_many.rs

toasty_core/schema/app/relation/
has_many.rs
