33 lines
1.3 KiB
Rust
33 lines
1.3 KiB
Rust
//! Provider interface and context for computed/display-only fields.
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//!
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//! Implementors provide logic to compute a field's display value from the
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//! other field values in the form.
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/// Context information provided to computed field calculations
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#[derive(Debug, Clone)]
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pub struct ComputedContext<'a> {
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/// All field values in the form (index -> value)
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pub field_values: &'a [&'a str],
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/// The field index being computed
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pub target_field: usize,
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/// Current field that user is editing (if any)
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pub current_field: Option<usize>,
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}
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/// User implements this to provide computed field logic
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pub trait ComputedProvider {
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/// Compute value for a field based on other field values.
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/// Called automatically when any field changes.
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fn compute_field(&mut self, context: ComputedContext) -> String;
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/// Check if this provider handles the given field.
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fn handles_field(&self, field_index: usize) -> bool;
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/// Get list of field dependencies for optimization.
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/// If field A depends on fields [1, 3], only recompute A when fields 1 or 3 change.
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/// Default: depend on all fields (always recompute) with a reasonable upper bound.
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fn field_dependencies(&self, _field_index: usize) -> Vec<usize> {
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(0..100).collect()
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}
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}
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