Wire Adapters Support

Wire Adapter Considerations

Considerations for List Adapters

List- or collection-oriented adapters such as getListUi, getRelatedListRecords, and getRelatedListCount have limited support for offline updates. Specifically, list logic isn’t re-evaluated for changes made while you’re offline. That is, if you create or modify a record offline and it falls into or out of the list criteria, the record isn’t added or removed from the list until you’re back online. The list updates only after the changes sync back to Salesforce. This limitation affects list membership, but does not affect the display of records that are a part of a list.

Here’s an example to make this clear. Let’s say you use getRelatedListRecords as a source to display a list of records, and the related list criteria limits list membership to accounts whose name begins with “A”. While offline, if you update one of those records to change an account name to begin with a “B”, from “Apple” to “Banana”, that record will still display in the list, with the updated account name “Banana”. Once you return online, the change syncs to Salesforce, and the list criteria is reevaluated. The Banana account will no longer be a member of the related list, and the wire adapter is updated, triggering a component refresh. The list of records returned by getRelatedListRecords won’t include the record for the Banana account, and it will disappear from the list displayed in your component’s user interface.

Considerations for getRecordUi

In theory, if you’re able to limit changes to records while offline to the scalar (non-relationship, non-metadata affecting) fields of that record, then invoking getRecordUi on that record should work as documented. In practice this is challenging, and when you miss it results in inconsistent or incorrect behavior that can be hard to troubleshoot. If you must use it, exercise extreme caution.

Handle Errors Defensively

When handling errors returned by wire adapters there’s potentially an issue with the “shape” of the error response. In contexts outside LWC Offline, the response returns a single error object. However, when an LWC wire adapter receives an error running in an LWC Offline-enabled mobile app, the response is returned as an array of error objects—most often, an array containing just one error object.

To make your components compatible across environments, we recommend a small amount of defensive coding at the start of your error handling. Convert a non-array into an array to ensure that the error shape is consistent:

let errors = ...; // errors from wire adapter
if ( ! Array.isArray(errors) ) {
    errors = [ errors ];
}