Nested strings and special characters for DataWindow object properties

Tilde (~) is the escape character that allows you to nest quoted strings within other quoted strings and to specify special characters such as tabs and carriage returns. For DataWindow object properties, several levels of nested strings can create a complicated expression.

Both double and single quotes are valid delimiters for strings. You can use this fact to simplify the specification of nested strings.

There are two ways to embed a string within another string. You can:

• Use the other type of quotation mark for the nested string. If the main string uses double quotes, the nested string can use single quotes.

  "If(state='MA',255,0)"
  

• Use the escape character to specify that a quote is part of the string instead the closure of a previous quote.

  "If(state=~"MA~",255,0)"
  

If the string includes a third level of nested strings, you need to add another tilde which must be accompanied by its own escape character, a second tilde. This is the reason that tildes are usually specified in odd numbers (1, 3, or 5 tildes).

This Modify expression (entered on a single line in code) shows three levels of nested strings:

dw_1.Modify(

	 "DataWindow.Color = '255 ~t If(state= ~'MA~',255,0)'")

This version of the expression has more tildes because there are no single quotes:

dw_1.Modify("DataWindow.Color = ~"255 ~t If(state= ~~~"MA~~~",255,0)~"")

Strings can also include special characters, as shown in the previous example. This table lists the special characters that are most often used in DataWindow expressions.

A line break is a carriage return plus a newline (\r\n).

A special case of specifying tildes involves the EditMask.SpinRange property, whose value is two numbers separated by a tilde (not an escape character, simply a tilde). To specify this value in a script, you must use a nested string with four tildes, which is interpreted as a single tilde when parsed:

dw_1.Modify("benefits.EditMask.SpinRange='0~~~~10'")

For more information about nested strings and special characters, see the PowerScript Reference.