camel-language-rhai

Rhai scripting language for rust-camel

Overview

camel-language-rhai provides a Rhai scripting language integration for rust-camel, similar to Apache Camel's Groovy or JavaScript language support. Rhai is an embedded scripting language for Rust with no external dependencies.

Available Variables

Scripts have access to these variables injected from the Exchange:

Variable	Type	Description
`body`	String	Message body as text
`headers`	Map	Message headers as a key-value map

Available Functions

Function	Description
`header("name")`	Look up a header value by name
`set_header("key", value)`	Set a header; visible within the same script evaluation but not propagated back to the Exchange
`property("name")`	Look up an exchange property by name
`set_property("key", value)`	Set a property; visible within the same script evaluation but not propagated back to the Exchange

Note: set_header and set_property allow scripts to pass values between statements within a single evaluation (e.g. set a header then read it back later in the same script). Changes do not persist after the script completes because expressions receive a read-only &Exchange reference.

Usage

use camel_language_rhai::RhaiLanguage;
use camel_language_api::Language;

let lang = RhaiLanguage::new();

// Predicate using header lookup
let pred = lang.create_predicate(r#"header("type") == "order""#).unwrap();

// Expression with string concatenation
let expr = lang.create_expression(r#"body + " processed""#).unwrap();

// Full Rhai scripting
let expr = lang.create_expression(r#"
    if header("priority") == "high" {
        "URGENT: " + body
    } else {
        body
    }
"#).unwrap();

Registration

use camel_language_rhai::RhaiLanguage;

let mut ctx = CamelContext::new();
ctx.register_language("rhai", Box::new(RhaiLanguage::new())).unwrap();

License

Apache-2.0