Method setContext

src/construct.ts:237–246

* This can be used to set contextual values. * Context must be set before any children are added, since children may consult context info during construction. * If the key already exists, it will be overridden. * @param key The context key * @param value The context value

(key: string, value: any)

   * @param value The context value
   */
  public setContext(key: string, value: any) {
    if (this.children.length > 0) {
      const names = this.children.map(c => c.node.id);
      throw new Error('Cannot set context after children have been added: ' + names.join(','));
    }
    if (!this._context) {
      this._context = {};
    }
    this._context[key] = value;
  }

  /**
   * Retrieves a value from tree context if present. Otherwise, would throw an error.