Introducing Flow Base Components

NOTE: The Flow Base Components package has been superseded by the Flow Action BasePack and Flow Screen Component Base Pack. If you’re a developer, use those as your prerequisites.

Most components available on UnofficialSF now use the Actions Base Pack and Screen Components Base Pack, described above. A few existing older components still use and require the original Flow Base Components.

As more Flow extensions get built, some components are proving to be popular and reused. To manage this more effectively and minimize conflicts that prevent installation, we’ve created this single base component library. If you want to use one of these components, we recommend that you make this package a dependency and reference the components here. This will help ensure your extension can be easily installed.

There isn’t going to be a managed package version of this because that would put the lightning components into a custom namespace, and lwc doesn’t currently allow lightning components to be used across namespaces

The current components included in Flow Base Components are:

Expression Builder

A full expression builder. Generates formula strings for output, and these can be evaluated at runtime by the Evaluate Formula action, which is part of this package.


Flow Combobox

This is essential for any custom property editor. It provides a picklist showing upstream merge fields.


Formula Builder

A full formula builder. Generates formula strings for output, and these can be evaluated at runtime by the Evaluate Formula action, which is part of this package.


Object and Field Picker

Provides a drop in component for selecting Objects or Object/Field combinations.


Show Toast

A simple local action that pops a toast up. Works with Screen flows only.

Learn more.

Transfer Metadata

A screen component that can retrieve or deploy any salesforce metadata.

Learn more.

Quick Choice

Learn more here.

Dual ListBox

Learn more here.

Usage Notes

All of the classes and components in this repo have been given a prefix of ‘fbc_’ this looks a little like a namespace but it is not. This is an unlocked package in the c namespace.

For sample code showing how to reference these, take a look at Update Field, a Flow Action that makes extensive use of this base component package. Here are some examples:

Referencing a base screen component

Pay particular note to the mixed use of hyphens and underscores:

Referencing a class method

Referencing methods and components from an lwc

Note the different syntax:


1.3.4 Unlocked

10/4 fixed test bug.

Version Information

1.3.3 Unlocked 10/1 fixes QuickChoice naming conflict

1.3.2 Unlocked 9/26 Adds QuickChoice and DualListBox. Also reduces the size of the MetadataService file to avoid the ‘1 million character’ limit.

1.2.6 Unlocked
9/3/20 – Eric Smith – Updated to Escape and Unescape the {} characters so the metadata string value can be handled by a flow

1.2.5 Unlocked 9/1
9/1/20 – Eric Smith – Added Extracted Metadata String and Escaped Metadata String outputs to the RetrieveMetadata and the TransferMetadata components

1.2.4 bug fixes

1.2.3 bug fixes to Flow Combobox

1.2.2: improvements to Transfer Metadata

In version 1.2.1, Flow Base Components gains:

  • Transfer Metadata
  • Show Toast

Flow Base Components already contains:

  • Expression Builder
  • Formula Builder
  • Flow Combobox
  • Pick Object and Field

View Source


Old Versions

1.2.4 Unlocked 8/21

1.2.3 Unlocked 8/5

1.2.2 Unlocked 7/26

1.2.1 Unlocked 7/25