Showing a spinner when dynamically loading resources for your SPFx property pane
In your SharePoint Framework web parts, you have the option to load resources dynamically. These resources could be data you want to fetch or dynamically load controls before the property pane panel gets shown. To achieve this, you implement the logic in the loadPropertyPaneResources method. Info: You can find more information about dynamically loading controls here: Special property pane dynamic loading.
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