You can use the GRT shell to help understand the catalog_utils.grt.lua module. Open the GRT shell by pressing Ctrl F3 or by selecting the GRT Shell menu option found under the View, Advanced menu options.

Notice that the getPluginInfo function makes use of the grtV module by invoking its getObj function. The grtV module is a built-in Lua module that assists with working from the GRT shell. To find out more about the grtV module, type ? grtV in the GRT shell console window. You should see something similar to the following:

  GRT Value Management Library - grtV
  -----------------------------------
  A library that contains functions to work with GRT values.

  clearList               child                fromXml
  getContentType          getKey               getListItemByObjName
  getn                    getGlobal            insert
  load                    newDict              newList
  newObj                  remove               save
  setGlobal               toLua                toXml
  typeOf

Typing help grtV.<command> displays help on a specific command. For example, entering help grtV.newObj displays the following output.

  GRT Value Management Library - grtV.newObj
  ------------------------------------------
  Creates a new GRT object initialized with the optional given values. All simple values
  ("int", "string", "real") are initialized and all lists and dicts are created.
  Object references are left null.

  grtV.newObj (structName[, initValuesDict])

  Parameters:
  structName         Struct name of the object to create
  initValuesDict     A dictionary containing initial values for object fields.


  Examples:
  rdbmsMgmt= grtV.newObj("db.mgmt.Management",
  {name="rdbmsManagement", owner=app})
  Create a new object from the struct "db.mgmt.Management"

The grtV.newObj function is used by both the objectPluginInput and the getPluginInfo functions of the catalog_utils.grt.lua module. A structName is the first parameter for the grtV.newObj function. In the case of the objectPluginInput function in catalog_utils.grt.lua module, the structName is app.PluginObjectInput. To find out more about this struct, locate it in the Structs window.