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.
Techniques for quoting nested strings
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.1"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.1"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:
|
1 |
dw_1.Modify( |
|
1 |
"DataWindow.Color = '255 ~t If(state= ~'MA~',255,0)'") |
This version of the expression has more tildes because there
are no single quotes:
|
1 |
dw_1.Modify("DataWindow.Color = ~"255 ~t If(state= ~~~"MA~~~",255,0)~"") |
Common special characters
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.
|
Escape sequence |
Meaning |
|---|---|
|
~t |
Tab |
|
~r |
Carriage return |
|
~n |
Newline or linefeed |
|
~” |
Double quote |
|
~’ |
Single quote |
|
~~ |
Tilde |
A line break is a carriage return plus a newline (
).
Special use of tilde
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:
|
1 |
dw_1.Modify("benefits.EditMask.SpinRange='0~~~~10'") |
More information
For more information about nested strings and special characters,
see the PowerScript Reference.