<root>
<text>
Text
</text>
<repeated>
<user>
<name>Mariano</name>
<lastName>de Achaval</lastName>
<age>36</age>
</user>
<user>
<lastName>Shokida</lastName>
<name>Leandro</name>
<age>30</age>
</user>
<user>
<age>29</age>
<name>Ana</name>
<lastName>Felissati</lastName>
</user>
<user>
<age>29</age>
<lastName>Chibana</lastName>
<name>Christian</name>
</user>
</repeated>
</root>
XML Format
MIME type: application/xml
ID: xml
The XML data structure is mapped to DataWeave objects that can contain other
objects, strings, or null
values. XML uses unbounded elements to represent collections, which are mapped to repeated keys in DataWeave objects. In addition, DataWeave natively supports namespaces
, CData
an xsi:types
.
The DataWeave reader for XML input supports the following parsing strategies:
-
Indexed
-
In-Memory
-
Streaming
To understand the parsing strategies that DataWeave readers and writers can apply to this format, see DataWeave Parsing Strategies.
CData
Custom Type
CData
is a custom DataWeave data type for XML that is used to identify a character data (CDATA) block. The CData
type makes the XML writer wrap content inside a CDATA
block or to check for an input string inside a CDATA
block. In DataWeave, CData
inherits from the type String
.
DocType
Custom Type
DocType
is a custom DataWeave data type for XML that is used to identify a doctype declaration (DTD).
Read and Write DTDs
Introduced in DataWeave 2.5.0. Supported by Mule 4.5.0 and later.
DataWeave can read and write doctype declarations in XML files.
To read a doctype declarations, set the system property com.mulesoft.dw.xml_reader.parseDtd
.
During the reading phase, DataWeave parses the doctype declarations and stores the content as metadata of the root element. The DocType
value is stored in the docType
variable. You can use the metadata selector (^
) to extract the value of that variable with an expression like this one:
-
payload.^docType
You can use the metadata selector to access it.
- NOTE
-
DTDs are disabled by default even if their declarations are read or written. For details, see XML reader property
supportDtd
in Reader Properties.
Examples
The following examples show uses of the XML format.
Refer to DataWeave Formats for more detail on available reader and writer properties for various data formats.
Example: Stream Input XML Data
This example shows how to set up XML streaming, which requires you to specify the following reader properties:
-
streaming=true
-
collectionPath="root.repeated"
The collectionPath
setting selects the elements to stream.
When streaming, the XML parser can start processing content without having all the XML content.
Input
The following XML serves as the input payload to the DataWeave source. Assume that it is the content of an XML file myXML.xml
.
Source
The reader property settings in the DataWeave script tell the XML reader to stream the input and process the repeated keys. The script uses the DataWeave map
function to iterate over the repeated keys.
%dw 2.0
var myInput readUrl('classpath://myXML.xml', 'application/xml', {streaming:true, collectionPath: "root.repeated"})
output application/dw
---
myInput.root.repeated.*user map {
n: $.name,
l: $.lastName,
a: $.age
}
Example: Null or Empty String in XML
Because there is no standard way to represent a null
value in XML, the reader maps the value to null
when the nil
attribute is set to true
.
Input
The following XML serves as the input payload to the DataWeave source.
Notice the nil
setting in <xsi:nil="true"
/>.
<book xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<author xsi:nil="true"/>
</book>
Example: Output null
Values for Missing XML Values
The XML reader property nullValueOn
accepts the value blank
(the default) or empty
.
This example uses the nullValueOn
default, so it maps the values of the title
and author
elements to null
.
Input
The following XML serves as input to the DataWeave source. Notice that the title
and author
elements lack values.
Assume that this input is content within the file, myInput.xml
.
<book>
<author></author>
<title>
</title>
</book>
Example: Output null
Values for Missing XML Values
The XML reader property nullValueOn
accepts the value blank
(the default) or empty
.
The example maps the value of the title
element to a String
and value of the author
element to null
because the XML reader property nullValueOn
is set to empty
.
Input
The following XML serves as input to the DataWeave source. Notice that the title
and author
elements lack values. The difference between the two elements is the space between the starting and ending tags. The tags of the title
element are separated by line breaks (the hidden characters, \n
), while the tags of the author
element are not separated by any characters.
Assume that this input is content within the file, myInput.xml
.
<book>
<author></author>
<title>
</title>
</book>
Source
The DataWeave script uses a DataWeave variable to input the content of myXML.xml
and applies the nullValueOn: "empty"
to it. The script transforms the XML input to JSON.
%dw 2.0
var myInput readUrl('classpath://myXML.xml', 'application/xml', {nullValueOn: "empty"})
output application/json
---
myInput
Example: Represent XML Attributes in the DataWeave (dw) Format
This example maps XML attributes to a canonical DataWeave representation,
the application/dw
format and MIME type.
Input
The XML serves as the input payload to the DataWeave source. Notice that the input contains XML attributes.
<users>
<company>MuleSoft</company>
<user name="Leandro" lastName="Shokida"/>
<user name="Mariano" lastName="Achaval"/>
</users>
Example: Represent XML Namespaces in the DataWeave (dw) Format
This example maps XML namespaces to a canonical DataWeave representation,
the application/dw
format and MIME type.
Input
The XML serves as the input payload to the DataWeave source. Notice that the input contains XML namespaces.
<root>
<h:table xmlns:h="http://www.w3.org/TR/html4/">
<h:tr>
<h:td>Apples</h:td>
<h:td>Bananas</h:td>
</h:tr>
</h:table>
<f:table xmlns:f="https://www.w3schools.com/furniture">
<f:name>African Coffee Table</f:name>
<f:width>80</f:width>
<f:length>120</f:length>
</f:table>
</root>
Source
The DataWeave script transforms the XML input payload to the DataWeave (dw) format and MIME type.
%dw 2.0
output application/dw
---
payload
Output
The output shows how the DataWeave (dw) format represents the XML input. Notice how the namespaces from the XML are represented.
ns h http://www.w3.org/TR/html4/
ns f https://www.w3schools.com/furniture
---
{
root: {
h#table: {
h#tr: {
h#td: "Apples",
h#td: "Bananas"
}
},
f#table: {
f#name: "African Coffee Table",
f#width: "80",
f#length: "120"
}
}
}
Example: Create a CDATA Element
This example shows how to use the CData
type to create a CDATA element in the XML output.
Example: Check for CDATA in a String
This example indicates whether a given String
value is CDATA.
Input
The XML serves as the input payload to the DataWeave source. Notice that the
test
element contains a CDATA block.
<?xml version='1.0' encoding='UTF-8'?>
<test><![CDATA[A text <a>]]></test>
Example: Use the inlineCloseOn
Writer Property
This example uses the inlineCloseOn
writer property with the value none
to act on the key-value pairs from the input.
Example: Transforms Repeated JSON Keys to Repeated XML Elements
XML encodes collections using repeated (unbounded) elements. DataWeave represents unbounded elements by repeating the same key.
This example shows how to convert the repeated keys in a JSON array of objects into repeated XML elements.
Input
The JSON input serves as the payload to the DataWeave source. Notice that the
name
keys in the array are repeated.
{
"friends": [
{"name": "Mariano"},
{"name": "Shoki"},
{"name": "Tomo"},
{"name": "Ana"}
]
}
Source
The DataWeave script selects the value of the friends
key.
%dw 2.0
output application/xml
---
friends: {
(payload.friends)
}
Output
The output represents the name
keys as XML elements.
<?xml version='1.0' encoding='UTF-8'?>
<friends>
<name>Mariano</name>
<name>Shoki</name>
<name>Tomo</name>
<name>Ana</name>
</friends>
See also, Example: Outputting Self-closing XML Tags.
Example: Transform XML Elements to JSON and Replace Characters
This example iterates over an XML file that contains details of employees, such as the Id
, Name
, and Address
, and converts the file into JSON format. The DataWeave script uses the replace
function to iterate over each Address
element and replace the characters -
and /
with blank space.
Input
The XML input serves as the payload to the DataWeave source. Notice that the Address
element contains -
and /
characters.
<?xml version='1.0' encoding='UTF-8'?>
<root>
<employees>
<Id>1</Id>
<Name>Mule</Name>
<Address>MuleSoft Avenue - 123</Address>
</employees>
<employees>
<Id>2</Id>
<Name>Max</Name>
<Address>MuleSoft Avenue-456/5/e</Address>
</employees>
</root>
Source
The following DataWeave script iterates over the payload elements and performs a mapping to an object. The instruction payload01.Address replace /([\-\,\/])/ with " "
replaces the -
and /
characters with blank spaces.
%dw 2.0
output application/json
---
payload.root.*employees map ((payload01 , indexOfPayload01) ->
{
Id: payload01.Id as String,
Name: payload01.Name as String,
Address: payload01.Address replace /([\-\,\/])/ with " "
}
)
Example: Read DTD value
The following DataWeave script transforms the XML input payload that contains a DocType
value into JSON. Notice that extracts the value of that doctype directive using the expression payload.^docType
.
Input
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE cXML SYSTEM "http://xml.cxml.org/schemas/cXML/1.2.014/cXML.dtd">
<cXML xml:lang="en-US" payloadID="1615232861.000506@prd327utl1.int.coupahost.com" timestamp="2021-03-08T11:47:42-08:00">
<Header>
<From>
<Credential domain="NetworkID">
<Identity>TestIdentity</Identity>
</Credential>
</From>
<To>
<Credential domain="TEST">
<Identity>Identity</Identity>
</Credential>
</To>
</Header>
</cXML>
Example: Write a DTD Value
This example shows how to use the docType
metadata to create a DocType
value in the XML output.
Source
%dw 2.0
output application/xml
ns xml http://www.w3.org/XML/1998/namespace
var cXmlObj = {
cXML @(payloadID: "9949494", xml#lang: "en-US", timestamp: "2002-02-04T18:39:09-08:00"): {
Header: {
From: {
Credential @(domain: "NetworkId"): {
Identity: "Identity"
}
}
}
}
} as Object {
docType: { rootName: "cXML", systemId: "http://xml.cXML.org/schemas/cXML/1.2.014/cXML.dtd" }
}
---
cXmlObj
Output
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE cXML SYSTEM "http://xml.cXML.org/schemas/cXML/1.2.014/cXML.dtd">
<cXML payloadID="9949494" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US" timestamp="2002-02-04T18:39:09-08:00">
<Header>
<From>
<Credential domain="NetworkId">
<Identity>Identity</Identity>
</Credential>
</From>
</Header>
</cXML>
Example: Transform DTD Value to a String Representation
This example uses Dtd Module (dw::xml::Dtd) to transform
a DocType
value that includes a systemId
to a string representation.
Input
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE cXML SYSTEM "http://xml.cxml.org/schemas/cXML/1.2.014/cXML.dtd">
<cXML xml:lang="en-US" payloadID="1615232861.000506@prd327utl1.int.coupahost.com" timestamp="2021-03-08T11:47:42-08:00">
<Header>
<From>
<Credential domain="NetworkID">
<Identity>Identity</Identity>
</Credential>
</From>
<To>
<Credential domain="TEST">
<Identity>Identity</Identity>
</Credential>
</To>
</Header>
</cXML>
Configuration Properties
DataWeave supports the following configuration properties for this format.
Reader Properties
This format accepts properties that provide instructions for reading input data.
Parameter | Type | Default | Description |
---|---|---|---|
|
|
|
Sets the path to the location in the document where the collection is located. Accepts a path expression that identifies the location of the elements to stream. |
|
|
|
Indicates whether to process external entities. Disabled by default to avoid XML External Entity (XXE) attacks. Valid values are |
|
|
|
Uses the indexed reader by default when reaching the threshold. Supports US-ASCII, UTF-8 and ISO-8859-1 encodings only. For other encodings, DataWeave uses the in-memory reader. Valid values are |
|
|
|
Sets the maximum number of characters accepted in an XML attribute. Available since Mule 4.2.1. |
|
|
|
Sets the maximum number of entity expansions. The limit helps avoid Billion Laughs attacks. |
|
|
|
Indicates whether to read an element with empty or blank text as a Valid values are |
|
|
|
Configures the type of optimization for the XML parser to use. Valid values are |
|
|
|
Streams input when set to Valid values are |
|
|
|
Enable or disable DTD support. Disabling skips (and does not process) internal and external subsets. You can also enable this property by setting the Mule system property Valid values are |
Writer Properties
This format accepts properties that provide instructions for writing output data.
Parameter | Type | Default | Description |
---|---|---|---|
|
|
|
Size of the buffer writer. The value must be greater than 8. |
|
|
|
Specifies the default namespaces of the output XML. |
|
|
|
Generates the output as a data stream when set to Valid values are |
|
|
|
Escapes double quotes in the XML declaration when set to Valid values are |
|
|
|
The encoding to use for the output, such as UTF-8. |
|
|
|
Escapes Valid values are |
|
|
|
Escapes '>' characters when set to Valid values are |
|
|
|
Write indented output for better readability by default, or compress output into a single line when set to Valid values are |
|
|
|
Write an inline close tag, or explicitly open and close tags when the value is Valid values are |
|
|
|
Valid values are |
|
|
|
Skips
Valid values are |
|
|
|
Writes the XML header declaration when set to Valid values are |
|
|
|
Marks the namespaces to declare in the root element of the XML:
|
|
|
|
Writes the Valid values are |