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Command Contracts

Core command support in @cratis/arc is built around typed command classes generated from backend command definitions.

ICommand

The core command interface provides execution and state-management capabilities:

interface ICommand<TCommandContent = object, TCommandResponse = object> extends ICanBeConfigured {
    readonly route: string;
    readonly roles: string[];
    readonly propertyDescriptors: PropertyDescriptor[];
    execute(
        allowedSeverity?: ValidationResultSeverity,
        ignoreWarnings?: boolean
    ): Promise<CommandResult<TCommandResponse>>;
    validate(): Promise<CommandResult<TCommandResponse>>;
    clear(): void;
    setInitialValues(values: TCommandContent): void;
    setInitialValuesFromCurrentValues(): void;
    revertChanges(): void;
    readonly hasChanges: boolean;
    propertyChanged(property: string): void;
    onPropertyChanged(callback: PropertyChanged, thisArg: object): void;
}

Change Tracking

Commands track property changes automatically.

hasChanges indicates whether current values differ from the baseline.
setInitialValues() sets an explicit baseline.
setInitialValuesFromCurrentValues() snapshots current values as baseline.
revertChanges() restores baseline values.
validate() runs the server-side authorization and validation path without executing the handler.

Property Change Notifications

Commands expose property-change callbacks for reactive flows:

command.onPropertyChanged((property: string) => {
    console.log(`Property ${property} changed`);
});

See Also