Question

I want to run Protovis javascript from Java and get the evaluated SVG code. I am using javax.script.* to run the Javascript:

public static void EvalScript() throws Exception {
    ScriptEngineManager factory = new ScriptEngineManager();
    ScriptEngine engine = factory.getEngineByName("JavaScript");
    Object result = engine.eval("var vis = new pv.Panel().width(300).height(300)
        .add (pv.Line).data ([1,0.5, 0.1, 0.01, 0.001, 0.3, 0.2,0.1,1])
           .left (function () { return this.index * 30; })
           .bottom (function (d) { return d * 250; });
        vis.root.render();
        vis.scene[0].canvas.innerHTML;");         
    System.out.println(result);
}

This would complain because I never loaded Protovis itself, as would ordinarily be done with

<script type="text/javascript" src="../protovis-r3.1.0.js"></script> 

Is there a good way, short of sourcing in the full Javascript into the eval() command, of loading a library when running Javascript through javax.script?

Answer 1

Well why would you not load the whole script in and hand it to eval()? If you want that Javascript execution context to parse and interpret the library, then something has to do that. You could of course supply a mechanism to the script context to let the script itself do the equivalent of the <script> tag example you gave, but it would end up being exactly the same thing.

I don’t understand your comment about Rhino. The Javascript interpreter in JDK 1.6 is Rhino.