Variable column grid

A variable column grid is a grid FDF that expands to fill its containing cell. It adjusts the repetitions in the columns dimension to fit into the containing cell. There is always at least one column rendered, no matter how much space there is in the containing cell.

In the FDF Editor, the Columns field is not used for setting up a variable column grid. Instead, the Initial Columns and Max Columns fields are used. The Initial Columns value is used for the columns dimension during the initial render of the grid. The value can be a non-negative integer, smaller than or equal to the Max Columns value. If the value is omitted, the number of columns initially rendered is calculated from the specified width of the cell containing the grid. The Max Columns value is the maximum value for a number of repetitions in the columns dimensions for the grid. This can be a non-negative integer.

More information is provided in the Help text in the FDF Editor.

This table describes the possible combinations of the orientation and pager type for the variable column grid, and the behavior of the variable column grid and repeated layout table:

Orientation	Pager type	Variable column grid behavior	Expanding columns honored for the repeat layout table
Horizontal	Classic	Yes	Yes
Horizontal	Extend	Yes	Yes
Vertical	Classic	No	No
Vertical	Extend	No	No

This table describes grid dimension fields for grid types and record fetch behavior for pager types:

Variable column grid	Grid dimension fields	Pager type	Ready records size	Fetch size
No	Rows Columns	Classic	Initial Specified value or Rows x Columns Subsequent Same as initial	Initial Rows x Columns + Ready records + 1 Subsequent Rows x Columns
No	Rows Columns	Extend	Initial Not used Subsequent Not used	Initial Rows x Columns + 1 Subsequent Rows x Columns
Yes	Rows Initial Columns Max Columns	Classic	Initial Specified value or Rows x Initial Columns Subsequent Specified value or Rows x Actual Rendered Columns	Initial Rows x Initial Columns + Initial Ready Records + 1 Subsequent Rows x Actual Rendered Columns + Records missing to get a full page + 1
Yes	Rows Initial Columns Max Columns	Extend	Initial Not used Subsequent Not used	Initial Rows x Initial Columns + 1 Subsequent Rows x Actual Rendered Columns + Records missing to get a full row + 1

A variable column grid is initially rendered using the Initial Columns value for the columns dimension. This allows the grid to be immediately rendered. After initial rendering, the client code arranges the grid in a dimension suitable for the grid container, and requests more records as needed.