How clean are my children?

nested-form.js

this.workflowResource.saveNodeConfig(this.node.id, this.approvalPath, this.variant)
    .then(() => {
        this.notificationsService.success('SUCCESS', 'Workflow configuration updated');
        this.$rootScope.$broadcast('configUpdated');
        this.$scope.contentFlowForm.$setPristine();

        // shouldn't need to do this...
        // check that all child forms of the contentForm are pristine, then reset contentForm
        let parentPristine = this.$scope.contentFlowForm.$$parentForm.$$controls
            .filter(c => Object.prototype.hasOwnProperty.call(c, '$submitted'))
            .every(x => x.$dirty === false);   

        if (parentPristine) {
            this.$scope.contentFlowForm.$$parentForm.$setPristine();
        }
    }, err => this.notificationsService.error('ERROR', err));