Derive Macro SwiftMessage 

#[derive(SwiftMessage)]
{
    // Attributes available to this derive:
    #[field]
    #[sequence]
    #[validation_rules]
}

Derive macro for SwiftMessage trait implementation

Generates message-level parsing, validation, and field management code. Supports field specifications and validation rules for complete SWIFT message types.

Basic Usage

use swift_mt_message_macros::{SwiftMessage, serde_swift_fields};
use serde::{Deserialize, Serialize};
use crate::fields::*;

#[serde_swift_fields]
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, SwiftMessage)]
struct MT103 {
    // Mandatory fields (no Option wrapper)
    #[field("20")]
    field_20: Field20,
     
    #[field("32A")]
    field_32a: Field32A,
     
    // Optional fields (wrapped in Option)
    #[field("50A")]
    field_50a: Option<Field50A>,
     
    // Repetitive fields (wrapped in Vec)
    #[field("71A")]
    field_71a: Option<Vec<Field71A>>,
}

Field Attributes

The #[field("tag")] attribute maps struct fields to SWIFT field tags:

• #[field("20")] - Maps to SWIFT field 20
• #[field("32A")] - Maps to SWIFT field 32A with option
• Field tags must match the SWIFT standard exactly

Field Types

• Mandatory: field_20: Field20 - Required field
• Optional: field_50: Option<Field50> - Optional field
• Repetitive: field_71a: Vec<Field71A> - Multiple occurrences
• Optional Repetitive: field_71a: Option<Vec<Field71A>> - Optional multiple

Generated Methods

The macro generates these methods for the SwiftMessageBody trait:

• message_type() -> &'static str - Returns message type (e.g., “103”)
• from_fields(fields: HashMap<String, Vec<String>>) -> Result<Self> - Parse from field map
• to_fields(&self) -> HashMap<String, Vec<String>> - Convert to field map
• required_fields() -> Vec<&'static str> - List required field tags
• optional_fields() -> Vec<&'static str> - List optional field tags