736: Mainline

Next, you add the apparatus required to determine that a file has been selected, to extract information from the file, and to assign a value to the foodList variable:

CalorieViewManager method definition • instance 
resetListBox 
  | theFileDialog file | 
  (theFileDialog := FileDialog new) 
    fileSpec: '*.dta'; 
    open. 
  (file := theFileDialog file) notNil 
    ifTrue: 
      [foodList := (Food collectFrom: file). 
       ...].