Microsoft Dynamics NAV contains fields called FlowFields. These are fields whose contents are constantly changing. The value of the contents of a FlowField is calculated each time you open the window containing the field. FlowFilters are used to determine how information is included when the contents of FlowFields are calculated.
FlowFields are used to display amounts and quantities that must always be up-to-date. The calculation can be based on information in tables other than the one that contains the field.
When viewing a list, you can specify a FlowFilter basically the same way you specify other filters. Click the page title menu and then select Limit totals. On the filter pane, you can specify what FlowFilters should be used.
An example of a FlowField is the Balance field, which is in the G/L Account table. You can see the Balance field on the G/L Account card, but the information on which the balance is based is taken from the Entry table, which contains posted general ledger entries. Similarly, the contents of the Balance field for a customer is based on information in the Customer Ledger Entry table, and so on.
The only information that you can change in the G/L Account, Customer, Vendor and Item tables is basic information such as addresses and codes. Financial information in these tables is displayed in FlowFields, but cannot be changed directly. This information is calculated from information in ledger entry tables. You can change information in the ledger entry tables by posting entries.
The FlowFilter function allows you to temporarily limit which entries in the other tables should be included in the calculation. You do this by defining a FlowFilter in the window in which the result of the calculation will be displayed (for example, the result of the calculation for the Balance field will appear on the Customer card). The filter will be used in the ledger entry table (in this case the Customer Ledger Entry table), when the ledger entries are calculated.