Content Length Metadata Selector (.^contentLength) November 21, 2021 Dataweave / Mule 4 / Mulesoft 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) November 21, 2021 Dataweave / Mule 4 / Mulesoft Returns the value of specified metadata for a Mule payload, variable, or attribute.
Filter Selectors (myKey[?($ == “aValue”)]) November 21, 2021 Dataweave / Mule 4 / Mulesoft 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 (!, ?) November 21, 2021 Dataweave / Mule 4 / Mulesoft 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 (#) November 21, 2021 Dataweave / Mule 4 / Mulesoft # returns the XML namespace of a selected key as plain text.
XML Attribute Selector (.@myKey) November 21, 2021 Dataweave / Mule 4 / Mulesoft Using .@ without the key name returns an object containing the attributes as key-value pairs.
Range selector (anIndex to anotherIndex) November 21, 2021 Dataweave / Mule 4 / Mulesoft 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 ([]) November 21, 2021 Dataweave / Mule 4 / Mulesoft 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) November 21, 2021 Dataweave / Mule 4 / Mulesoft 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.
Descendants Selector (..) November 21, 2021 Dataweave / Mule 4 / Mulesoft The descendants selector (..) is the perfect tool to use when you need the values for a certain key no matter where they appear in a piece of data.