msgReject

Reject the current call with an error message.

import { msgReject, msgArgData, candidDecode, IDL, update } from 'azle';

export default class {
    @update([IDL.Text], IDL.Empty, { manual: true })
    validateAndProcess(input: string): void {
        if (input.length === 0) {
            msgReject('Input cannot be empty');
            return;
        }

        if (input.length > 100) {
            msgReject('Input too long: maximum 100 characters allowed');
            return;
        }

        // Process normally if validation passes
        const result = `Processed: ${input}`;
        const encoded = candidEncode([IDL.Text], [result]);
        msgReply(encoded);
    }
}

The msgReject function manually rejects the current method call with an error message. This is used in methods marked with { manual: true }.

Parameters:

• message: Error message to include in the rejection (string)

Returns: void

Use Cases:

• Custom error handling in manual methods
• Input validation with specific error messages
• Conditional rejection based on complex logic
• Advanced error response formatting

Important Notes:

• Only use in methods with { manual: true }
• Call this exactly once per method execution
• Cannot be combined with msgReply
• Equivalent to throwing an error in regular methods