epoxyViewModel.js

var ViewModel = Backbone.Epoxy.Model.extend({
  defaults: {
    editorOpen: false,
    editable: true,
    required: false
  },
  computeds: {
    deleteVisible: function() {
      return !this.getBinding("editorOpen") &&
        this.getBinding("editable") && 
        !this.getBinding("required");
    },
    editVisible: function() {
      return !this.getBinding("editorOpen") &&
        this.getBinding("editable");
    }
  }
});

var inst = new EditorView({
  model: model,
  viewModel: new ViewModel()
});