Block Properties

The next set of properties apply to blocks, although some only appear in form or report blocks and not both. The rowcount and X/Y delta form block properties have been described above under the data control properties.

Show Scroll Bar (showbar)

A block can show a scroll bar on the right hand side, which can be used to scroll through records that are displayed in the block and which indicates the position amongst the records; or it can display at the bottom left a small navigation tool, comprising buttons for moving to the first, previous, next or last record or to add a new record, plus a record counter. This property allows one of four settings, to display both, just one, or neither of these.

Note that some user confusion may occur if the form is resized and the scrollbar is displayed, since it is then possible to have a right-hand scrollbar which moves through records, and a horizontal scrollbar which scrolls (pans) the form left-right in the window.

Parent/Child (master, child)

These two properties are used to link data in a nested block to the data in the block which contains it. Parent is a column (or, in general, an expression) which will be retrieved with the data for the outer block; Child is a column (or expression) which applies to the nested block. The data which appears in the inner block comprises rows which have the same value for Child as the value of Parent in the outer block.

For instance, if the outer block retrieves data from the table Clients, and the nested block from Orders, with Parent and Child both set to ClientID, then the effect is much as if you had used the SQL query:

          select .....
          from   Clients, Orders
          where  Clients.ClientID = Orders.ClientID
        

The child property will also appear when editing the properties of the outermost block (ie., the form or report level block). This is not relevent unless the form is opened by a script, in which case parent-child linking can be provided between forms. See the openForm (and openReport) script functions later in the manual.

Tab Wrapping (tabswrap)

By default, tabbing out of the last control in the tab order moves to the first control on the next record, and back-tabbing out of the first control moves to the first control of the previous record. If this property is set then tabbing moves between controls in the same way, but without moving between records.

Read Only (blkrdonly)

Setting the block read-only property makes all controls within the block read-only, irrespective of their individual read-only settings. This is useful if you want a block that can ony display data, and does not allow any update.