SOM Expressions with Relative Indexes

Most SOM expressions I work with have an absolute index number, something like form1[0].[0].Table1[0].Row1[0].TextField1[0] where all the numbers within the square brackets are absolute numbers.  But these numbers can be relative, that is have a positive or negative sign.  So if I was on TextField1 of row 2 and wanted to reference TextField1 of row 1 I could use a SOM expression like;

Row1.resolveNode('Row1[-1].TextField1');

Similarly if I have a series of fields with the same name and so have different indexes, say TextField[0], TextFIeld[1] etc, I can reference the next field, in document order, called TextField with a SOM expression

this.resolveNode('TextField[+1]').rawValue

We can also refer to the next field without knowing it's name using the class name reference (that is with a "#" character).

this.resolveNode('#field[+1]').somExpression

or the next button

this.resolveNodes('#field.(ui.oneOfChild.className == "button")').item(1).somExpression

This sample gives examples of these expressions and uses a relative SOM expression to calculate a running total in a table.

RelativeIndex.pdf