Mashup Builder > Widgets > Expression Widget
  
Expression Widget
The Expression widget evaluates an expression and is invisible at run time.
The expression can be any JavaScript expression. For example:
Strings:
string1 === string2 or compare their lengths: string1.length >= string2.length
Booleans:
bool1 === bool2 Regex: /^hello/.test(string1)
DateTime:
date1 > date2 checks if the first date is greater than the second or date1 > new Date() checks if the inputted date is in the future
The parameter baseType does not matter, instead it’s how the data gets passed into the expression. For example, if you set all your parameters as string, you are still able to switch between using a Date Time Picker widget or Numeric Entry widgets without having to change the parameters baseType.
View the following video tutorial for more information: How to Use an Expression Widget.
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Styles and common widget properties are not included in the table below.
Property Name
Description
Base Type
Default Value
Bindable? (Y/N)
Localizable? (Y/N)
Expression
The expression to evaluate.
STRING
n/a
N
N
AutoEvaluate
Automatically evaluate the expression when the value of its inputs change.
BOOLEAN
False
N
N
FireOnFirstValue
A boolean value indicating whether the Changed Event should be fired when the Expression widget is supplied its first value.
BOOLEAN
False
N
N
DataChangeType
The type of data change that must occur to fire the Changed Event (Value, Always, or Never).
BOOLEAN
Value
N
N
Output
The output of the expression.
NUMBER
n/a
Y
N
OutputBaseType
The base type of the output (NOTHING, BOOLEAN, DATETIME, LOCATION, NUMBER, TAGS, or STRING).
STRING
NUMBER
N
N
Changed
Event. The Event fired by the Expression widget when its output is changed.
n/a
n/a
Y
N
Evaluate
Service. Evaluates the expression.
n/a
n/a
Y
N
Visible
Is the widget visible in runtime?
BOOLEAN
True
Y
N