Class Metadata Selector (.^class)
Returns the class of the Plain Old Java Object (POJO). The value might result from calling a method in a Java class or have a data type (such as String or DateTime) that DataWeave treats as a Java value.
Dataweave
Content Length Metadata Selector (.^contentLength)
In the following Mule app flow, the Logger uses payload.^contentLength to select the length of the string my string, set in the Set Payload (set-payload) component.
Metadata Selector (.^someMetadata)
Returns the value of specified metadata for a Mule payload, variable, or attribute.
Filter Selectors (myKey[?($ == “aValue”)])
myKey[?($ == "aValue")] returns only the values of matching keys within an array or object. Note that ? is also used in Key Present Validator. If no key-value pairs match, the result is null.
Selector Modifiers (!, ?)
You can check for the presence of a given key.
! evaluates the selection and fails with an exception message if the key is not present.
? returns true if the selected key is present, false if not. Note that ? is also used in
Filter Selectors (myKey[?($ == "aValue")]).
Namespace Selector (#)
# returns the XML namespace of a selected key as plain text.
XML Attribute Selector (.@myKey)
Using .@ without the key name returns an object containing the attributes as key-value pairs.
Range selector (anIndex to anotherIndex)
If you need multiple sequential values from an Array, DataWeave allows you to select a range of values with the range selector ([n to m]).
Index Selector ([])
The index selector returns the element at the specified position. It can be applied over an array, object, or string.
Key-Value Pair Selector (.&myKey)
The & selector acts on arrays and objects. & retrieves both the keys and values of all matching keys pairs in the current context. These are returned as an object, containing the retrieved keys and values.