Write data

Data is written to a storage with a storagemanager if:

  • At least the StorageName property is configured to a data-item or it’s parent-item. Often other StorageManager properties are also needed/useful.
  • The StorageManager supports writing data.
  • An expression is configured for the data item, or derived from it’s parent item.
  • The property disablestorage is not configured or set or set to false (default value).
  • The property storagereadonly is not configured or set to false (default value).

The last two properties work hierarchical, if configured to a parent item they also apply to each of their subitem. They can be overruled for specific subitems.

example

container WithContext
{
   template export
   {
      // begin case parameters
      parameter<uint32> n;
      // end case parameters

      unit<uint32> i := range(uint32, 0, n)
      ,  StorageName = "= '%LocalDataProjDir%' + PropValue(., 'FullName') + '/i.dbf'"
      {
         attribute<uint32>  sqr  := id(i) * id(i);
         attribute<float64> sqrt := sqrt(float64(sqr));
      }
   }
   container exports
   {
      container a := export(30);
      container b := export(40);
   }
}

file and folder

The StorageName property configures both folder as well as file name for the export. If the item for which the StorageName is configured is updated, the resulting storage will be made. In the example a file i.dbf is written when item i is updated. The folder consists of two components:

  • %LocalDataProjDir%, a folders-and-placeholders referring to the LocalDataProjDir on your local machine
  • propvalue (., ‘FullName’), a context string referring to the full path of the parent of the item with the StorageName. By using this context string, the resulting folder for the two case instantions will differ.

We advice to always configure both folder and file name. If no folder is configured, the storage will be written to your %ConfigDir%. If no file is configured, an error is generated.

Since GeoDMSVersion 7.140, it is also possible to add the %configname% placeholder to your foldername. This is useful if you project consists of multiple configurations (e.g. Vesta).