Dynamically choosing TextBlock and Shapes

I want to choose TextBlock dynamically based on our nodedataarray.

For example,

diagram.add(
    $(go.Part, "Vertical",
      $(go.TextBlock, { text: "a Text Block" }), //Textblock 1
      $(go.TextBlock, { text: "a Text Block", stroke: "red" }),  //Textblock 2
      $(go.TextBlock, { text: "a Text Block", background: "lightblue" }),  //Textblock 3
      $(go.TextBlock, { text: "a Text Block", font: "bold 14pt serif" })  //Textblock 4
    ));

Now, I want to choose only Textblock 1 for 1st node and Textblock 3 for 5th node. (Dynamically I want to mention which Textblock need to be choosed while defining node in nodearray

Can you help in this?

What do you mean by “choose”? What is it that is supposed to distinguish the TextBlocks in those cases?