XSLT component

Q: How do I pass a value into the stylesheet?

Declare at the top level and set a header (or exchange property) named x before the xslt step.

Q: How do I produce JSON with XSLT?

Use and write the JSON with xsl:text and xsl:value-of, as in the example. For a generic XML-to-JSON mapping without a stylesheet, use xj.

Q: Is XSLT 2.0 or 3.0 supported?

XSLT 1.0 fully; version="2.0" stylesheets get the XSLT 2.0 core (grouping, functions, regex). XSLT 3.0-only instructions such as xsl:iterate and xsl:try fail with a TransformerConfigurationException naming the instruction.

The xslt component transforms the XML message body with an XSLT stylesheet and sets the result (XML, HTML or text) as the new body.

Scheme: xslt: · Crate: cameleer-xml · Cargo feature: xml · Consumer: no · Producer: yes · Apache Camel: XSLT

When to use it

Turn legacy XML (SOAP payloads, EDI exports, partner feeds) into the JSON an agent tool or a REST API expects, with xsl:output method="text".
Map one XML vocabulary to another (order formats, invoice standards).
Render XML to HTML reports.
Reuse XSLT 1.0 stylesheets from an existing Camel or BizTalk-style integration.

URI format

text

xslt:templateResource[?options]

templateResource is a file path relative to the working directory, file:path, classpath:path (read as a relative path, there is no classpath) or ref:beanName (a String in the registry). xsl:include, xsl:import and document() resolve relative to the stylesheet file.

Example

A partner sends orders as XML; an agent tool wants compact JSON. The stylesheet writes JSON text, and the currency header arrives as the xsl:param of the same name.

xml

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="text"/>
  <xsl:param name="currency" select="'USD'"/>
  <xsl:template match="/order">
    <xsl:text>{"id":"</xsl:text><xsl:value-of select="@id"/>
    <xsl:text>","customer":"</xsl:text><xsl:value-of select="customer/name"/>
    <xsl:text>","currency":"</xsl:text><xsl:value-of select="$currency"/>
    <xsl:text>","lines":[</xsl:text>
    <xsl:for-each select="line">
      <xsl:sort select="@sku"/>
      <xsl:text>{"sku":"</xsl:text><xsl:value-of select="@sku"/>
      <xsl:text>","qty":</xsl:text><xsl:value-of select="@qty"/>
      <xsl:text>}</xsl:text>
      <xsl:if test="position() != last()">,</xsl:if>
    </xsl:for-each>
    <xsl:text>],"total":</xsl:text>
    <xsl:value-of select="format-number(sum(line/@price), '0.00')"/>
    <xsl:text>}</xsl:text>
  </xsl:template>
</xsl:stylesheet>

yaml example: xslt-order-to-json

- route:
    id: xslt-order-to-json
    from:
      uri: direct:xslt-order
      steps:
        - setHeader:
            name: currency
            constant: EUR
        - to: xslt:xsl/order-to-json.xsl

xml

<order id="A-17">
  <customer><name>Ada Lovelace</name></customer>
  <line sku="Z9" qty="1" price="12.5"/>
  <line sku="B2" qty="3" price="30"/>
</order>

json

{"id":"A-17","customer":"Ada Lovelace","currency":"EUR","lines":[{"sku":"B2","qty":3},{"sku":"Z9","qty":1}],"total":42.50}

XML to XML

xml

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" omit-xml-declaration="yes"/>
  <xsl:template match="/person">
    <contact name="{first} {last}"><xsl:copy-of select="email"/></contact>
  </xsl:template>
</xsl:stylesheet>

yaml example: xslt-xml-to-xml

- route:
    id: xslt-rename
    from:
      uri: direct:xslt-rename
      steps:
        - to: xslt:xsl/rename.xsl

xml

<person><first>Grace</first><last>Hopper</last><email>grace@example.com</email></person>

xml

<contact name="Grace Hopper"><email>grace@example.com</email></contact>

Rust DSL

rust

b.from("direct:xslt-rust")
    .set_header("currency", constant("GBP"))
    .to("xslt:xsl/order-to-json.xsl");

Options

option	default	description
`output`	`string`	`string`, `bytes`, `DOM` (serialized XML text, as there is no DOM type) or `file` (written to the file named by the `CamelXsltFileName` header; the body becomes the file path).
`contentCache`	`true`	Compile the stylesheet once. Set `false` to re-read it for every message.
`failOnNullBody`	`true`	Fail when the body is null.
`deleteOutputFile`	`false`	With `output=file`, delete the file when the exchange completes.
`allowTemplateFromHeader`	`false`	Use the `CamelXsltStylesheet` / `CamelXsltResourceUri` headers when present.

Accepted and ignored (Java-only settings): transformerFactory, transformerFactoryClass, transformerFactoryConfigurationStrategy, uriResolver, uriResolverFactory, resultHandlerFactory, entityResolver, errorListener, xsltMessageLogger, transformerCacheSize, allowStAX, lazyStartProducer.

Parameters: exchange properties, then message headers, are passed as global xsl:param values, as in Camel.

What the processor supports

A complete XSLT 1.0 processor: templates with match patterns, priorities and modes, apply-templates, call-template, parameters, variables, for-each, choose, sort, copy/copy-of, element/attribute, number, key(), format-number(), document(), generate-id(), exsl:node-set(), and xsl:output with the xml, html and text methods. Stylesheets with version="2.0" get XPath 2.0 and the XSLT 2.0 core; see xslt-saxon.

Message headers

header	direction	description
`CamelXsltFileName`	in	Output file for `output=file`.
`CamelXsltStylesheet`	in	Stylesheet text used instead of the resource (needs `allowTemplateFromHeader=true`).
`CamelXsltResourceUri`	in	Stylesheet resource used instead of the endpoint's one (needs `allowTemplateFromHeader=true`).
any header	in	Available to the stylesheet as an `xsl:param` with the header's name.

Run it with Docker

docker run --rm -v "$PWD:/routes:ro" pmsudhi/cameleer run /routes/order-to-json.camel.yaml

Relative stylesheet paths resolve against /routes, the image's working directory.

Common questions

How do I pass a value into the stylesheet?

Declare <xsl:param name="x"/> at the top level and set a header (or exchange property) named x before the xslt step.

How do I produce JSON with XSLT?

Use <xsl:output method="text"/> and write the JSON with xsl:text and xsl:value-of, as in the example. For a generic XML-to-JSON mapping without a stylesheet, use xj.

Is XSLT 2.0 or 3.0 supported?

XSLT 1.0 fully; version="2.0" stylesheets get the XSLT 2.0 core (grouping, functions, regex). XSLT 3.0-only instructions such as xsl:iterate and xsl:try fail with a TransformerConfigurationException naming the instruction.

xslt-saxon: the same processor under Camel's Saxon scheme.
xj, xquery, validator.
XPath language.
Apache Camel XSLT component

Found a problem?

If something on this page doesn't match what Cameleer does, or you hit a bug while building with it, please help fix it, whether you are a person or a coding agent: open an issue that describes what you saw, then fork the repository, fix it, add or update a test, run cargo test --workspace, and open a pull request. CONTRIBUTING.md explains the ground rules.