Many components allow you to specify Filter Column and Filter Value fields. These are designed to be used together to act as a lookup table of sorts, in order to get the corresponding value from another column in the dataset.
The Filter Column and Filter Value fields are used together to enable the component to select a specific cell from the data set. It is often used in conjunction with an Actual Column value.
- The Actual Column defines the column of the dataset that will be used to get the value for the component.
- Filter Column expands this by allowing you to select a different column in the same dataset to use as a key to enable the selection of a specific cell from the Actual Column. The system will look at the Filter Column values, and will go through each cell in that column until it finds one that matches the Filter Value.
- When it finds the first match for Filter Value, it then gets the value from the Actual Column, from that same row, and returns that to the control as the value to use.
In the following example, a Tank component (from version 4.3.2) shows you how a hard-coded Filter Column and Filter Value affects the tank fill level.
| Actual Column | Actual Column defines the column of the dataset that will be used to return the value used by the component. This can be used in conjunction with the Filter Column and the Filter Value settings to enable the selection of a single cell from that column. |
| Filter Column | Defines the column of the dataset that, when combined with Filter Value, is used as a key to enable the selection of a specific cell from the Actual Column. |
| Filter Value | Defines the row of the dataset that, when combined with Filter Column, is used as a key to enable the selection of a specific cell from the Actual Column. |
In the following example, the Tank component uses a variable (previously called event) as a filter to determine the tank level. The variable is driven by the user selecting a value from a combo box. This combo box contains the list of items in the KPI Type column of the dataset. When the user selects an item (corresponding to a row on the dataset), the variable stores this information and the Tank knows to follow that row to get the fill value.
