abbot.script.Expression Maven / Gradle / Ivy

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package abbot.script;

import java.util.Iterator;
import java.util.Map;

import javax.script.ScriptException;

import org.jdom.CDATA;
import org.jdom.Element;


/** Provides evaluation of arbitrary Java expressions.  Any Java expression is
    supported, with a more loose syntax if desired.  See the
    groovey documentation for
    complete details of the extended features available in this evaluator.
    
    Note that any variables declared or assigned will be available to any
    subsequent steps in the same Script.
 */

public class Expression extends Step {

    public static final String TAG_EXPRESSION = "expression";

    private static final String USAGE = "{java/groovey expression}";
    private String expression = "";

    public Expression(Resolver resolver, Element el, Map attributes) {
        super(resolver, attributes);

        String expr = null;
        Iterator iter = el.getContent().iterator();
        while (iter.hasNext()) {
            Object o = iter.next();
            if (o instanceof CDATA) {
                expr = ((CDATA)o).getText();
                break;
            }
        }
        if (expr == null)
            expr = el.getText();
        setExpression(expr);
    }

    public Expression(Resolver resolver, String description) {
        super(resolver, description);
    }

    public String getDefaultDescription() { 
        return getExpression();
    }
    public String getUsage() { return USAGE; }
    public String getXMLTag() { return TAG_EXPRESSION; }

    protected Element addContent(Element el) {
        return el.addContent(new CDATA(getExpression()));
    }

    public void setExpression(String text) {
        expression = text;
    }

    public String getExpression() {
        return expression;
    }

    /** Evaluates the expression. */
    protected void runStep() throws Throwable {
        Interpreter sh = (Interpreter)
            getResolver().getProperty(Script.INTERPRETER);
        try {  
            sh.eval(ArgumentParser.substitute(getResolver(), getExpression()));
        }
        catch(ScriptException e) {
            throw e;
        }
    }
}