A data node is a container for operations producing or manipulating data. Each operation produces a table or a graph. The last table produced by the sequence of operations is the data node's result table.
A data node can be based on another data node in the same project, its parent node. If it has a parent node, the parent node's result table is the input of the data node.
Each operation is performed by an operator based on some settings and possibly on some input data such as a table produced by a previous operation, the result table of the parent node, a TIS Table, or a file.
A (non-empty) data node hence consists of
- a sequence of operations, and
- optionally, a reference to another data node in the same project (the parent node).
A data node is empty if it does not reference another data node and its sequence of operations is empty.
If the data node has no parent node, then the first operation of the data node produces a table, e.g., by applying operator Create table or Read TIS table 8.0. Each subsequent operation takes as part of its input (if any) the table created by its predecessor.
Only the result table of a data node is displayed by the TIS Editor. Tables produced by intermediate operations can be displayed by deactivating subsequent operations (see description of "Operations" tab in Operation).
Note that only data nodes of the same TIS Project can be referenced as parent node. If another TIS Project's data node is required as input, it has to be saved as TIS Table by operator Write TIS Table 7.0 in the other project, and read into the current project by operator Read TIS table 8.0.
The Project containing the data node summarizes meta data on a data node, such as row and column count, number of children, in its list of data nodes.
The contents of a data node can be manipulated by clicking on it on the Overview tab of its TIS Project and then selecting the "Details" or the "Operations" tab.
The "Details" tab
A data node's "Details" tab shows its result table. Data in the result table can be filtered (see Result Table Filter).
Above this table, the following information can be added to the data node.
Data node: Name of the currently selected data node and or more Data Node Flags.
Caption: Name of the data node.
Description: To add a note which is then shown in the "Description" field of the project's overview on the data nodes.
Based on: Reference to the parent node whose result table serves as input table for this data node.
Update: "Automatically" – update data node automatically when opened; "Manually" – update data node manually by clicking "Recalculate"; "Fixed" – data node cannot be updated, see Recalculation process between data nodes.
Properties: TIS Board connection – when checked, then the data node is available to TIS Board and can be accessed by the Portlet Designer.
The "Operations" tab
A data node's "Operations" tab allows to add, delete, and modify operations on the data node. See Operation to learn about this tab.