Lightning Web Components Overview

Lightning Web Components (LWC) is a programming model used to build custom HTML elements. These custom elements, the web components, are made using HTML and modern JavaScript. Because of this, LWC is an efficient way to add high-performing custom elements. LWC is an open-source technology. Like any other Javascript framework (example: Angular, React), Pulsar can run custom HTML/JS apps written in LWC even when offline as long as they are using the data layer API Pulsar provides.

For more information about Lightning Web Components, refer to Salesforce Developers.

Lightning Data Service Overview

Lightning Data Service (LDS) caches and shares records across components. LDS provides performance improvements by loading a record only once for use by multiple records on a page. LDS manages data for you, and changes to a record are reflected in all components using that record. LDS is built on top of the User Interface API (UI API), making it easy to create Salesforce pages. These pages are efficient because data requests return both data and metadata.

LDS helps code perform well by loading the record data and caching it client-side. Using the cached data is faster than requesting this data from the server. The cache is updated with server requests at the end of its lifetime. This results in fewer server requests. It is important to note that the cache timeout is separate from the layout timeout, so changes to the layout will only be displayed if you reload after the timeout or log out and log back in.

LDS is not an open-source technology. It requires the Salesforce server to run.

For more information about Lightning Data Server, refer to Salesforce Developers.

Do LWC apps using LDS work with Pulsar in offline mode?

Unless Salesforce decides to open-source the Lightning Data Service, only Salesforce can run apps using Lightning Web Components and the Lightning Data Service at this time. They may work offline with the cached data for SF or SFS Mobile, but they will not work within Pulsar if you are offline since the LDS framework is not available because it’s not published for integration by Salesforce.

If you have an LWC app that can be published as a link/URL, it certainly can be accessed within Pulsar by launching in a webview when you are online.