KeyBuilder DSL Details

This page explains the syntax and features of the KeyBuilder DSL in KiviGo.

Template Syntax

• Use {field} to inject variables into the key string.
• Fields can be provided via map[string]any, struct fields, or custom KeyVars interface.
• All fields in the template must be provided, or an error is returned.

Supported Input Types

• Map: map[string]any for dynamic values
• Struct: Any Go struct, fields are extracted automatically
• Custom Interface: Implement KeyVars() map[string]any for advanced scenarios (see Advanced Usage)

Input Types priority

When building a key, the input type is resolved in the following order:

1. Custom Interface: If the input implements KeyVars, its KeyVars() method is used.
2. Map: If the input is a map[string]interface{}, its values are used.
3. Struct: If the input is a struct (or pointer to struct), exported fields are used.

This ensures maximum flexibility and allows you to override variable extraction logic as needed.

Examples

Map Example

builder, err := key.Template("order:{orderID}:user:{userID}")
if err != nil {
    // handle error (invalid template)
}
key, err := builder.Build(ctx, map[string]any{"orderID": 123, "userID": "alice"})
// key == "order:123:user:alice"

Struct Example

type Order struct {
    OrderID int
    UserID  string
}
builder, err := key.Template("order:{OrderID}:user:{UserID}")
if err != nil {
    // handle error (invalid template)
}
order := Order{OrderID: 456, UserID: "bob"}
key, err := builder.Build(ctx, order)
// key == "order:456:user:bob"

Error Handling

If any template field is missing, Build returns an error listing missing fields.

See the Advanced Usage page for more complex scenarios.