guru.nidi.graphviz.engine.GraphvizJdkEngine Maven / Gradle / Ivy

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/*
 * Copyright (C) 2015 Stefan Niederhauser ([email protected])
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package guru.nidi.graphviz.engine;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import java.util.Map;
import java.util.stream.Collectors;

public class GraphvizJdkEngine extends AbstractGraphvizEngine {
    private final static ScriptEngine ENGINE = new ScriptEngineManager().getEngineByExtension("js");

    public GraphvizJdkEngine() {
        this(null);
    }

    public GraphvizJdkEngine(EngineInitListener engineInitListener) {
        super(false, engineInitListener);
    }

    @Override
    protected String doExecute(String dot) {
        try {
            return (String) ENGINE.eval("$$prints=[]; Viz('" + jsEscape(dot) + "');");
        } catch (ScriptException e) {
            if (e.getMessage().startsWith("abort")) {
                try {
                    throw new GraphvizException(((Map) ENGINE.eval("$$prints"))
                            .values()
                            .stream()
                            .map(Object::toString)
                            .collect(Collectors.joining("\n")));
                } catch (ScriptException e1) {
                    //fall through to general exception
                }
            }
            throw new GraphvizException("Problem executing graphviz", e);
        }
    }

    @Override
    protected void doInit() throws Exception {
        ENGINE.eval("var $$prints=[], print=function(s){$$prints.push(s);};");
        ENGINE.eval(vizCode());
        ENGINE.eval("Viz('digraph g { a -> b; }');");
    }
}