packages/@alicloud/ros-cdk-core/lib/ros-condition.ts

import { Construct } from "./construct-compat";
import { IResolvable, IResolveContext } from "./resolvable";
import { RosElement } from "./ros-element";

export interface RosConditionProps {
  /**
   * The expression that the condition will evaluate.
   *
   * @default - None.
   */
  readonly expression?: IRosConditionExpression;
}

/**
 * Represents a RosTemplate condition, for resources which must be conditionally created and
 * the determination must be made at deploy time.
 */
export class RosCondition
  extends RosElement
  implements IRosConditionExpression, IResolvable {
  /**
   * The condition statement.
   */
  public expression?: IRosConditionExpression;

  /**
   * Build a new condition. The condition must be constructed with a condition token,
   * that the condition is based on.
   */
  constructor(scope: Construct, id: string, props?: RosConditionProps) {
    super(scope, id);
    this.expression = props && props.expression;
  }

  /**
   * @internal
   */
  public _toRosTemplate(): object {
    if (!this.expression) {
      return {};
    }

    return {
      Conditions: {
        [this.logicalId]: this.expression,
      },
    };
  }

  /**
   * Synthesizes the condition.
   */
  public resolve(_context: IResolveContext): any {
    return { Condition: this.logicalId };
  }
}

/**
 * Represents a RosTemplate element that can be used within a Condition.
 *
 * You can use intrinsic functions, such as ``Fn.conditionIf``,
 * ``Fn.conditionEquals``, and ``Fn.conditionNot``, to conditionally create
 * stack resources. These conditions are evaluated based on input parameters
 * that you declare when you create or update a stack. After you define all your
 * conditions, you can associate them with resources or resource properties in
 * the Resources and Outputs sections of a template.
 *
 */
export interface IRosConditionExpression extends IResolvable {}