Nav Table with parameter-driven functions - any way to allow users to enter parameter at preview?

To allow users to enter values for required parameters in a custom connector using the Power BI SDK, you can use the setDefaultValue method on the DataParameter object in your DataSource.ts file. This allows you to set a default value for the parameter that the user can then change in the first data preview dialog.

Here's an example:

const myParameter: DataParameter = {
name: "My Parameter",
dataType: DataType.String,
};

myParameter.setDefaultValue("Default Value");

this.dataSource.dataParameters.push(myParameter);

In this example, the parameter myParameter is created with a name of "My Parameter" and a data type of DataType.String. The setDefaultValue method is then used to set the default value of the parameter to "Default Value". Finally, the parameter is pushed onto the dataSource.dataParameters array.

This will display a prompt for the user to enter a value for the parameter when they click "Load Data" in the first data preview dialog.