Constant state of data items
To make the calculation steps of a model transparent, it is important that all intermediate results can be visualized.
Therefore data items have a constant state in a calculation process. Constructions often used in programming languages like A = A + 1 are therefore explicitly forbidden, as the value of variable A in such a construction is dependent on the progress in the calculation process and intermediate results can not easily be requested.
In a GeoDMS configuration each new value for variable A requests a new data item.
In the GeoDMS a data item can have one of the following states:
- Not Calculated (not yet calculated or a supplier is not anymore valid)
- MetaData updated (the metadata of a data item is ready. If the item is not red, it means the expression is ok in terms of it's metadata)
- Calculating
- Valid (if the calculations finished successfully)
- Failed (in case an error occurred at the meta or primary data level or an integrity check failed)
