FAQs

Yes. The standard interface includes text entry as well as drop down elements. You can enter the whole thing as text or just one component as text. Alternatively you can enter the whole thing as text with just one part coming from the graphic editor.

It really is completely flexible.

A context row is a row from a table like any other. The term 'context row' is used to refer to a row which is the context for a calculation expression.

Being the context row for an expression means that where column names are used in the expression they are presumed to refer to columns of the context row.

Each expression must be written with its context row type in mind. An expression intended to be evaluated in the context of a 'House' row will have access to different columns than one intended to be evaluated in the context of an 'Invoice' row.

Yes you can.

When you enter a calculation expression the system knows what return type the expression will produce and presents you with the formatting panel for that return type just as it would for a storage field of that same type.

In some search/find dialogs you are allowed to enter a 'search' expression. What this means is that you can enter an expression which will be evaluated for each row in the search target list.

Such an expression must evaluate to a logical(Boolean -TRUE/FALSE) type.

The rows for which the expression evaluates to TRUE will be 'found', the rest will not.

The context row type for the search expression is the row type of the target list.

In 'filter' and 'member' list functions a term is supplied as one of the arguments which is effectively a 'comparison' expression.

The 'comparison' function must return a logical(Boolean - TRUE/FALSE) data type.

Such functions always have another argument which accepts a list of rows. The row type of this list is the context row type for the 'comparison' expression.

The 'comparison' expression is evaluated in the context of each row in the target list one at a time. The function then uses these results in a way appropriate to its purpose.

The easy answer is 'It just can." :)

A list of rows is just a piece of data, like an integer or a piece of text. The only slight difference is that the list is not a copy of the actual data in the rows but only a list of references to the rows. This difference makes the system faster than it otherwise would be but does not affect the way you should think of them.

Yes you can.

In fact you can selectively turn it on or off for each view of each data type.

You may want to do this if your calculations take a long time in specific views and this is making the page clunky to work with.

When you disable 'Auto recalculate' a button appears in the top right of the page which can be clicked to carry out a recalculation of the pages calculated values. The button only appears when the calculation become out of date for some reason such as data changes.

When you add a calculation to a table you are adding a column to it in which all the cells will appear to contain a value which is calculated rather than stored.

You add such a column in the same way you add any column - by clicking the add column button on the table concerned. Then you select 'Derived Value' or 'Local Derived Value' as the type of the column.