class Duktape::Runtime

• Duktape::Runtime
• Reference
• Object

Overview

A Runtime is a simplified mechanism for evaluating javascript code without directly using the low-level Duktape API calls.

Instances of the Runtime class may evaluate code using an interface inspired by ExecJS. The method calls within this class all return the last evaluated value (with the exception of #exec).

rt = Duktape::Runtime.new
rt.eval("Math.PI") # => 3.14159

The Runtime class also allows for javascript initialization code:

rt = Duktape::Runtime.new do |ctx|
  ctx.eval! <<-JS
    function add_one(num){ return num + 1; }
  JS
end

rt.eval("add_one", 42) # => 43.0

The Runtime class is not loaded by default and must be required before using it:

require "duktape/runtime"

Also note that the Runtime class includes the base Duktape code for you and may be used in a standalone manner.

Defined in:

Constructors

• .new(timeout : Int32 | Int64)
• .new(context : Duktape::Context)
• .new
• .new(timeout : Int32 | Int64, &)
• .new(context : Duktape::Context, &)
• .new(&)

Instance Method Summary

• #call(prop : String, *args)

  Call the named property with the supplied arguments, returning the value of the called property.

• #call(props : Array(String), *args)

  Call the nested property that is supplied via an array of strings with the supplied arguments.

• #eval(source : String)

  Evaluate the supplied source code on the underlying javascript context and return the last value:

• #exec(source : String)

  Execute the supplied source code on the underyling javascript context without returning any value.

Constructor Detail

Instance Method Detail

rt = Duktape::Runtime.new
rt.call("JSON.stringify", 123) # => "123"

rt = Duktape::Runtime.new
rt.call(["Math", "PI"]) # => 3.14159

rt = Duktape::Runtime.new
rt.eval("1 + 1") => 2.0

rt = Duktape::Runtime.new
rt.exec("1 + 1") # => nil