Sometimes getting back undefined

Hello everyone,

I am working on a component that manages the add and edit form for customer data.
From the URL I get the id and load the data in the form. If there is no data it should display a message and changes the state to add mode. The problem is sometimes I get back undefined and right after I get the data, so I can't distinguish if the data will arrive very soon or if the record is deleted.

Many thanks in advance.
Lukas

Api
```
let CustomersApi;
if (Meteor.isClient) {
CustomersApi = new Ground.Collection('customers');
} else {
CustomersApi = new Mongo.Collection('customers');
}

export default CustomersApi;
```

Pass data to component
```
export default createContainer((props) => {
if(props.customerId){
return {
customer: CustomersApi.findOne({_id: props.customerId})
};
} else {
return {}
}
}, CustomerAddEdit);
```

Proccess received data
```
componentWillReceiveProps(nextProps){
if(this.state.editMode){
if(nextProps.customer){

this.setState({
customerData: nextProps.customer,
isFetching: false
});

} else {

UiMessagesController({
type: 'warning',
header: 'Kunde nicht verfügbar',
messages: '...'
})

this.setState({
editMode: false,
isFetching: false
});

}
}
}
```

Start with the createContainer callback and CustomersApi.findOne path shown in the issue, then trace when the customer data becomes available during component updates. Reproduce the undefined-then-data sequence with an existing and missing customer id, and define how loading and missing-record states should be distinguished.

Written by the indexing model from the issue text.