SharePoint framework property pane data

Question

Where the data of SharePoint framework property pane is saved.? Can't we access it directly? Also if we have deleted a instance of our app from the page, the property pane data gets deleted permanently?

Answer 1

In the properties pane config, you'll have something similar to this:

PropertyPaneSlider('TestSliderRed', {
    label: 'testSliderRedLabel',
    min: 0,
    max: 255,
    showValue: true,
}),

It's the value in the first part of the property ('TestSliderRed', in this case) that you're looking for. In order to access the value that the slider is currently set to, you'll need this:

var redVal = this.properties.TestSliderRed;

The variable can then be used where needed within your code.

Please note that the answer above assumes that you're trying to use the property value within the SPFx code and that you're trying to get the current property pane value that a user has set. Let us know if it's something else that you're looking for.

Regarding your second question, I believe that if an SPFx app is removed then you'll lose the property pane data, yes. One solution that I can think of is that you should be able to update a SharePoint list with the values if they're important to you. I've not tested, but can't see any reason why it wouldn't work.