If anybody is interested I found a solution (not sure if it is the best one). Just disabling the default close operation so the popup does not close on backround click, while closing it with data param on background click.
matDialogRef.disableClose = true;//disable default close operation
matDialogRef.backdropClick().subscribe(result => {
matDialogRef.close(dataToReturn);
});
This way the calling component receives the data whether the dialog was closed by button or clicked elsewhere.
OR
Call the close(dataToReturn) in the beforeClose() to set the dialog result:
constructor(public matDialogRef: MatDialogRef<MyDialogComponent>) {
matDialogRef.beforeClose().subscribe(() => matDialogRef.close(this.dataToReturn));
}
This will work if the dialog is closed by clicking on the backdrop, or pressing the ESC.
