See: The
PmaDataTable object
Various operations can be performed over values of the
PmaDataTable object. For example:
- Offering values (for read and write) into the
Web using the
XML format. The client requiring data from this Web component is of the
PmDataClient type from the licence point of view.
- Sorting rows by the
Sort method.
- etc.
The PmaDataTable object can be used in various ways:
It is possible, for example, to define columns in the development environment (see the "
Columns" tab), define how many rows have to be in the table (see the "
DataTable" tab) and then only read and write values in the running application (see the
GetCellValue and
SetCellValue methods) from this table.
It is also possible to define neither columns nor rows and to create and remove them dynamically in the running application (see the
InsertRow,
RemoveRow,
InsertCol,
RemoveCol methods). But adding and removing columns are limited by the fact that thereat even all rows of the table are removed.
It is possible to define columns and rows in the development environment and then to change them dynamically.
Maximum row number depends on
PROMOTIC runtime licence and is:
PmRtProf: 65535,
PmRtFree: 30 and
PmRtXX: XX (for example
PmRt100: 100).
Maximum number of columns depends on
PROMOTIC runtime licence and is:
PmRtProf: 65535,
PmRtFree: 30 and
PmRtXX: XX (for example
PmRt100: 100).
"Read-only" columns:
Each table cell is counted into the application size for the purpose of licencing. But if a column of table in the
PmaDataTable object is marked as
"Read-only", then the cells in this column are not counted into application size. This allows application designers to use this object for storing non-changing configuration values while the number of licenced variables is kept low. From the functional point of view this means that columns marked "Read-only" can be written only once. Limitations of individual methods of the
PmaDataTable object caused by "Read-only" columns are explained in remark of this method.
Each cell is empty at the beginning. The cell is considered empty also if it contains numeric value
0 or an empty string
"". New value can be written into such cell.
After writing a non-zero value into the "Read-only" column the cell is "locked". "Locked cell" becomes a constant and cannot be written again. Other still "unlocked" cells can be written into as needed.
Methods that write into multiple cells simultaneously will write the values only into "unlocked cells" while the content of "locked" cells remains unchanged.
If at least one cell is locked in "Read-only" column by writing non-empty value, then the whole structure of the table is locked. Then it is no longer possible to add or remove columns or rows or change the structure of the table. The structure and dimensions of the table must be defined and modified before writing first non-empty value into a cell in "Read-only" column.
The data representation in the panel:
The connection to values of the table can be defined directly in
Pmg objects by the "
PP" data binding. In the
object property enter point of this binding it must be entered manually the following:
Item(row,col), where
row and
col are indexes of the required row and column.
For displaying the whole table see examples:
