Script component

The Script component allows you to modify messages using scripts written in Groovy or JavaScript. The scripts can either be provided directly or uploaded as files. Scripts are able to read and modify the body, headers, and properties of messages that pass through it.

To simplify the development of scripts, the Script component offers the ability to evaluate scripts given a set of test values for the body, headers, and properties of a message.

Migration Guide

If you migrate from version 4.14.x or older then check the Scripts migration guide for new version of Groovy and JavaScript.

Configuration

The Script component has the following configuration options:

Upload method

Select if you want to enter the script manually in or through uploading a file.

Options:

• Enter script manually (default)
• Upload file

Script

The script that should be evaluated for each message passing through the component.

note

Only available when Upload method is set to Enter script manually.

Upload File

The script that should be evaluated for each message uploaded in the form of a file.

note

Only available when Upload method is set to Upload file.

Language

The language used for the script.

Options:

• JavaScript (default)
• Groovy

Tip: Prefer Groovy over JavaScript whenever possible

Groovy, like Camel, runs in the JVM (Java Virtual Machine) while Javascript runs via Node.js (and therefore has a higher impact on performance).

note

The JavaScript that you can use in the Script component is not the same implementation as in web browsers. It is an open source implementation of JavaScript for Java. We advice that you use standard JavaScript syntax also known as ES5. Newer syntax and other features are not supported at the moment.

In Headers

A list of comma-separated name-value pairs representing headers for testing purposes. The names and values should be quoted.

define in headers

Use the following format: "headerName"="value","anotherHeaderName"="value",etc

In Properties

A list of comma-separated name-value pairs representing properties for testing purposes. The names and values should be quoted.

in properties format

Use the following format: "propertyName"="value","anotherPropertyName"="value",etc

In Body

A body for testing purposes.

Out Headers

Shows the list of headers after validating the script. Not user editable.

Out Properties

Shows the list of properties after validating the script. Not user editable.

Out Body

Shows the body of the message after validating the script. Not user editable.

Validate script

Use this button to validate your script without having to install the flow. The In Headers, In Properties and In Body are used for the validation. The Out Headers, Out Properties and Out Body will be shown in their respective fields.

Using JavaScript

This section shows you examples of how to 'interact' with Camel messages using JavaScript in the Script component.

Working with headers

The examples below show you how to get, set and remove message headers using JavaScript.

// Get header 'myHeaderName' as is
var headerAsIs = message.getHeader("myHeaderName");
// Get header 'myHeaderName' as String
var headerAsString = message.getHeader("myHeaderName").toString();
// Get header 'myHeaderName' as Integer
var headerAsInt = parseInt(message.getHeader("myHeaderName").toString(), 10);

// Overwrite existing header 'myHeaderName'
message.setHeader("myHeaderName", "header value");

// Set new header 'newHeaderName'
message.setHeader("newHeaderName", "new header value");

// Remove header 'removeHeaderName'
message.removeHeader("removeHeaderName");

header As Int

If the header is not an integer while using the headerAsInt syntax above its value will be NaN (not a number).

// Example of building a body with the "myHeaderName" header as defined above
"This is my headerAsIs: "+headerAsIs+", "+
"this is my headerAsString: "+headerAsString+", "+
"this is my headerAsInt: "+headerAsInt+".";

Working with the body

The examples below show you how to work with the body using JavaScript.

// Get the body as is
var bodyAsIs = body;
// Get the body as String
var bodyAsString = body.toString();
// Get the body as Integer
var bodyAsInt = parseInt(body, 10);

JavaScript body

By default the last used variable is returned as the body. Refer to the examples on the tabs below.

JavaScript body 1

// Define a variable
var newBody = "This is my new body as a variable";
var anotherNewBody = "This is another new body";

// Use variables to set the body
newBody;

// Set the body
"My new body";

// Body result: My new body

JavaScript body 2

// Define a variable
var newBody = "This is my new body as a variable";
var anotherNewBody = "This is another new body";

// Use variables to set the body
newBody;

// Body result: This is my new body as a variable

JavaScript body 3

// Define a variable
var newBody = "This is my new body as a variable";
var anotherNewBody = "This is another new body";

// Body result: This is another new body

Import third party libraries

Use the import function to import third party libraries to be used in JavaScript scripts:

import("https://cdnjs.cloudflare.com/ajax/libs/crypto-js/3.1.9-1/crypto-js.min.js");
import("https://cdnjs.cloudflare.com/ajax/libs/crypto-js/3.1.9-1/hmac-sha256.min.js");
import("https://cdnjs.cloudflare.com/ajax/libs/crypto-js/3.1.9-1/enc-base64.min.js");

Using Groovy

This section shows you examples of how to 'interact' with Camel messages using Groovy in the Script component.

tip

See the Using time in Dovetail guide for more Groovy script examples related to time.

Working with headers

The examples below show you how to get, set and remove message headers using Groovy.

// Get header 'myHeaderName' as is
def headerAsIs = request.getHeader("myHeaderName");
// Get header 'myHeaderName' as String
def headerAsString = request.getHeader("myHeaderName", String.class);
// Get header 'myHeaderName' as Integer
def headerAsInt = request.getHeader("myHeaderName", Integer.class);

// Overwrite existing header 'myHeaderName'
request.setHeader("myHeaderName", "header value");

// Set new header 'newHeaderName'
request.setHeader("newHeaderName", "new header value");

// Remove header 'removeHeaderName'
request.removeHeader("removeHeaderName");

header As Int

If the header is not an integer while using the headerAsInt syntax above, the component will throw an error. Use try and catch to handle this error:

def headerAsInt = null
try {
    // Get header 'myHeaderName' as String
    def headerValue = request.getHeader("myHeaderName")
    if (headerValue != null) {
        // Try to convert the header value to Integer
        headerAsInt = headerValue.toInteger()
    } else {
        // Handle the case where the header is not present, if needed
        headerAsInt = "NaN"
    }
} catch (NumberFormatException e) {
    // Catch the error and set "NaN" value or any other default value
    headerAsInt = "NaN"
}

// Example of building a body with the "myHeaderName" header as defined above
"This is my headerAsIs: "+headerAsIs+", "+
"this is my headerAsString: "+headerAsString+", "+
"this is my headerAsInt: "+headerAsInt+".";

Working with the body

The examples below show you how to work with the body using Groovy.

// Get the body as is
def bodyAsIs = request.body;
// Get the body as String
def bodyAsString = request.getBody(String.class);
// Get the body as Integer
def bodyAsInt = request.getBody(Integer.class);

Groovy body

By default the last used variable is returned as the body. Refer to the examples on the tabs below.

body As Int

If the body is not an integer while using the bodyAsInt syntax above, the component will throw an error. Use try and catch to handle this error:

def bodyAsInt = null
try {
    // Get body 'mybodyName' as String
    def bodyValue = request.body
    if (bodyValue != null) {
        // Try to convert the body value to Integer
        bodyAsInt = bodyValue.toInteger()
    } else {
        // Handle the case where the body is not present, if needed
        bodyAsInt = "NaN"
    }
} catch (NumberFormatException e) {
    // Catch the error and set "NaN" value or any other default value
    bodyAsInt = "NaN"
}

Groovy body 1

// Define a variable
def newBody = "This is my new body as a variable";
def anotherNewBody = "This is another new body";

// Use variables to set the body
newBody;

// Set the body
"My new body";

// Body result: My new body

Groovy body 2

// Define a variable
def newBody = "This is my new body as a variable";
def anotherNewBody = "This is another new body";

// Use variables to set the body
newBody;

// Body result: This is my new body as a variable

Groovy body 3

// Define a variable
def newBody = "This is my new body as a variable";
def anotherNewBody = "This is another new body";

// Body result: This is another new body

Import third party libraries

Use the import function to import third party libraries to be used in Groovy scripts:

import javax.crypto.Mac
import javax.crypto.spec.SecretKeySpec
import java.net.URLEncoder

Example of Script evaluation

The image below shows the result of evaluating a script for a given body, set of headers and set of properties.

note

In the Flow Designer you enter test data in text inputs. If those text inputs are empty, the script is actually tested with empty strings. An empty text input is therefore not considered null. If the flow is running and the body is empty, it will be null and not "". If you convert this empty body to string you will get "null". It is best to test your script with null for the In Body.

Versions

Dovetail	Groovy version	Javascript version (Engine)
< 4.14.x	2.5	ECMAScript 5.1 (Nashorn)
> 4.15.0	3.0 Release notes	ECMAScript 2023 (GraalVM)
> 4.17.0	4.0 Release notes	ECMAScript 2023 (GraalVM)

Last update on Apr 22, 2024