Not only do Libraries allow easy access to Symbols and styles across documents, but those Symbols can be updated from the Library so your designs are always up-to-date.
Previously we talked about editing Components that belong to a Library, but when you return to your document after making changes to your Symbols, you can choose to accept those changes onto your document — or not.
After editing a Library Symbol or style and returning to your document, you will now see a purple Library Update Available badge on the top-right corner of the application window. If you click this, a dialog will appear letting you know that some components in your document are outdated.
Here you will see a list of Library Symbols and styles that are waiting to be updated, along with a handy “Old” and “New” preview so you can view the changes that have been made. If there’s a change that you’re not sure about or want to come back to later, click the checkbox to deselect it.
Any Symbols or Styles with a selected checkbox next to their name will update when you click “Update Symbols”. This will make changes to all instances of a style or Symbol across all Pages of your document.
In the dialog, if you see a change to a Symbol that you definitely do not want to make, then double-click an instance of it on the Canvas, and click “Unlink from Library”. This will turn the Library Symbol into a ‘local’ Symbol visible on your “Symbols” page.
You can find the “Unlink from Library” option for Text and Layer Styles at the top of the menu that appears when you click on the styles dropdown in the Inspector.