---
schema_version: "1"
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title: DataWeave Support in Flex Gateway Policies
collection: mulesoft
version: current
locale: en-us
portal_url: https://docs.salesforce.com/mulesoft/current/en-us/gateway/1.9/policies-flex-dataweave-support.md
canonical_url: https://docs.mulesoft.com/gateway/1.9/policies-flex-dataweave-support
source_site: docs.mulesoft.com
content_type: documentation
content_hash: d2c412564b19da0e1e7e6c0e828258f89b58ceb69b8aac0b21d3133a67dbc8aa
description: MuleSoft Documentation Site
release: "1.9"
latest: false
---
---
product: Omni Gateway
version: 1.9
---

# DataWeave Support in Flex Gateway Policies

> For the full documentation index, see: https://docs.mulesoft.com/llms.txt

[DataWeave](https://docs.mulesoft.com/dataweave/latest/) is the programming language designed by MuleSoft for data
transformation. It enables you to build a simple solution for a common integration developer use
case: read and parse data from one format, transform the data, and write it out as a different
format.

Flex Gateway supports a subset of DataWeave in policy configuration expressions. DataWeave is only
supported in included policies and custom policies created with PDK..

## Available Types

- [`Null`](https://docs.mulesoft.com/dataweave/latest/dataweave-type-system#null)

- `Boolean`

- `String`

- `Number` (Driven as 64 bits floating points)

- [`Array`](https://docs.mulesoft.com/dataweave/latest/dataweave-type-system#array-type)

- [`Object`](https://docs.mulesoft.com/dataweave/latest/dataweave-type-system#object-type) (Repeated keys are not
  available)

## Available Value Constructors for Types

- [`Boolean`](https://docs.mulesoft.com/dataweave/latest/dataweave-types#dw_type_boolean)

- [`String`](https://docs.mulesoft.com/dataweave/latest/dataweave-types#dw_type_string)

- [`Number`](https://docs.mulesoft.com/dataweave/latest/dataweave-types#dw_type_number)

- [`Array`](https://docs.mulesoft.com/dataweave/latest/dataweave-types#dw_type_array)

## Unavailable Value Constructors for Types

- [`Null`](https://docs.mulesoft.com/dataweave/latest/dataweave-types#dw_type_null) (Writing a `null` literal is not
  supported)

- [`Object`](https://docs.mulesoft.com/dataweave/latest/dataweave-types#dw_type_object) (Objects can not be defined as
  literals)

## Available Flow Control Structures

- [`if else`](https://docs.mulesoft.com/dataweave/latest/dataweave-flow-control#control_flow_if_else)

## Unavailable Flow Control Structures

- [`do`](https://docs.mulesoft.com/dataweave/latest/dataweave-flow-control#control_flow_do)

## Available Selectors

- `Array[Number]`

- `Array[String]`

- `Object[String]`

- `String[Number]`

## Unavailable Selectors

- `Object[Number]`

## Available Equality and Relational Operators

- [`==`](https://docs.mulesoft.com/dataweave/latest/dw-operators#equality-and-relational-operators)

- [`!=`](https://docs.mulesoft.com/dataweave/latest/dw-operators#equality-and-relational-operators)

- [`>=`](https://docs.mulesoft.com/dataweave/latest/dw-operators#equality-and-relational-operators)

- [`<=`](https://docs.mulesoft.com/dataweave/latest/dw-operators#equality-and-relational-operators)

## Available Logical Operators

- [`not`](https://docs.mulesoft.com/dataweave/latest/dw-operators#logical_operators)

- [`and`](https://docs.mulesoft.com/dataweave/latest/dw-operators#logical_operators)

- [`or`](https://docs.mulesoft.com/dataweave/latest/dw-operators#logical_operators)

## Available Default Operators

- [`default`](https://docs.mulesoft.com/dataweave/latest/dataweave-cookbook-defaults#example-of-using-the-keyword-default-to-set-a-default-value)

## Available Functions

### `++`

- [`++(Array<S>, Array<T>): Array<S | T>`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-plusplus#plusplus1)

- [`++(String, String): String`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-plusplus#plusplus2)

### `contains`

- [`contains(Array<T>, Any): Boolean`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-contains#contains1)

- [`contains(String, String): Boolean`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-contains#contains2)

### `lower`

- [`lower(String): String`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-lower#lower1)

- [`lower(Null): Null`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-lower#lower2)

### `splitBy`

- [`splitBy(String, String): Array<String>`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-splitby#splitby2)

### `sizeOf`

- [`sizeOf(Array<Any>): Number`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-sizeof#sizeof1)

- [`sizeOf(Object): Number`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-sizeof#sizeof2)

- [`sizeOf(String): Number`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-sizeof#sizeof4)

### `trim`

- [`trim(String): String`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-trim#trim1)

- [`trim(Null): Null`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-trim#trim2)

### `upper`

- [`upper(String): String`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-upper#upper1)

- [`upper(Null): Null`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-upper#upper2)

### `uuid`

- [`uuid(): String`](https://docs.mulesoft.com/dataweave/latest/dw-core-functions-uuid#uuid1)

### `dw::core::Strings::substringAfter`

- [`substringAfter(String, String): String`](https://docs.mulesoft.com/dataweave/latest/dw-strings-functions-substringafter#substringafter1)

- [`substringAfter(Null, String): Null`](https://docs.mulesoft.com/dataweave/latest/dw-strings-functions-substringafter#substringafter2)

### `dw::core::Strings::substringAfterLast`

- [`substringAfterLast(String, String): String`](https://docs.mulesoft.com/dataweave/latest/dw-strings-functions-substringafterlast#substringafterlast1)

- [`substringAfterLast(Null, String): Null`](https://docs.mulesoft.com/dataweave/latest/dw-strings-functions-substringafterlast#substringafterlast2)

### `dw::core::Strings::substringBefore`

- [`substringBefore(String, String): String`](https://docs.mulesoft.com/dataweave/latest/dw-strings-functions-substringbefore#substringbefore1)

- [`substringBefore(Null, String): Null`](https://docs.mulesoft.com/dataweave/latest/dw-strings-functions-substringbefore#substringbefore2)

### `dw::core::Strings::substringBeforeLast`

- [`substringBeforeLast(text: String, separator: String): String`](https://docs.mulesoft.com/dataweave/latest/dw-strings-functions-substringbeforelast#substringbeforelast1)

- [`substringBeforeLast(text: Null, separator: String): Null`](https://docs.mulesoft.com/dataweave/latest/dw-strings-functions-substringbeforelast#substringbeforelast2)

## Available Predefined Variables

- [`attributes`](https://docs.mulesoft.com/dataweave/latest/dataweave-variables-context)

  - `attributes.headers`

  - `attributes.method` (Only available in request context)

  - `attributes.queryParams` (Only available in request context)

  - `attributes.queryString` (Only available in request context)

  - `attributes.requestPath` (Only available in request context)

  - `attributes.requestUri` (Only available in request context)

  - `attributes.localAddress` (Only available in request context)

  - `attributes.remoteAddress` (Only available in request context)

  - `attributes.scheme` (Only available in request context)

  - `attributes.version` (Only available in request context)

  - `attributes.statusCode` (Only available in response context)

- [`authentication`](https://docs.mulesoft.com/dataweave/latest/dataweave-variables-context)

  - `authentication.clientId`

  - `authentication.clientName`

  - `authentication.principal`

  - `authentication.properties`

- `payload`

  - Use the `payload` variable to read the request body as a string. You can’t parse this variable.

- [`vars`](https://docs.mulesoft.com/dataweave/latest/dataweave-variables-context)

  - Individual policies support different sets of variables. For information, refer to the policies
    listed in [Inbound Policies Directory](https://docs.mulesoft.com/gateway/1.9/policies-included-directory).