javaparser-core/src/main/java/com/github/javaparser/printer/YamlPrinter.java

/*
 * Copyright (C) 2007-2010 Júlio Vilmar Gesser.
 * Copyright (C) 2011, 2013-2016 The JavaParser Team.
 *
 * This file is part of JavaParser.
 *
 * JavaParser can be used either under the terms of
 * a) the GNU Lesser General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 * b) the terms of the Apache License
 *
 * You should have received a copy of both licenses in LICENCE.LGPL and
 * LICENCE.APACHE. Please refer to those files for details.
 *
 * JavaParser is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 */

package com.github.javaparser.printer;

import static com.github.javaparser.utils.Utils.assertNotNull;
import static java.util.stream.Collectors.toList;

import java.util.List;

import com.github.javaparser.ast.Node;
import com.github.javaparser.ast.NodeList;
import com.github.javaparser.metamodel.NodeMetaModel;
import com.github.javaparser.metamodel.PropertyMetaModel;

/**
 * Outputs a YAML file containing the AST meant for inspecting it.
 */
public class YamlPrinter {

    private static final int NUM_SPACES_FOR_INDENT = 4;
    private final boolean outputNodeType;

    public YamlPrinter(boolean outputNodeType) {
        this.outputNodeType = outputNodeType;
    }

    public String output(Node node) {
        StringBuilder output = new StringBuilder();
        output.append("---");
        output(node, "root", 0, output);
        output.append(System.lineSeparator() + "...");
        return output.toString();
    }

    public void output(Node node, String name, int level, StringBuilder builder) {
        assertNotNull(node);
        NodeMetaModel metaModel = node.getMetaModel();
        List<PropertyMetaModel> allPropertyMetaModels = metaModel.getAllPropertyMetaModels();
        List<PropertyMetaModel> attributes = allPropertyMetaModels.stream().filter(PropertyMetaModel::isAttribute)
                .filter(PropertyMetaModel::isSingular).collect(toList());
        List<PropertyMetaModel> subNodes = allPropertyMetaModels.stream().filter(PropertyMetaModel::isNode)
                .filter(PropertyMetaModel::isSingular).collect(toList());
        List<PropertyMetaModel> subLists = allPropertyMetaModels.stream().filter(PropertyMetaModel::isNodeList)
                .collect(toList());

        if (outputNodeType)
            builder.append(System.lineSeparator() + indent(level) + name + "(Type=" + metaModel.getTypeName() + "): ");
        else
            builder.append(System.lineSeparator() + indent(level) + name + ": ");

        level++;
        for (PropertyMetaModel a : attributes) {
            builder.append(System.lineSeparator() + indent(level) + a.getName() + ": \""
                    + a.getValue(node).toString() + "\"");
        }

        for (PropertyMetaModel sn : subNodes) {
            Node nd = (Node) sn.getValue(node);
            if (nd != null)
                output(nd, sn.getName(), level, builder);
        }

        for (PropertyMetaModel sl : subLists) {
            NodeList<? extends Node> nl = (NodeList<? extends Node>) sl.getValue(node);
            if (nl != null && nl.isNonEmpty()) {
                builder.append(System.lineSeparator() + indent(level) + sl.getName() + ": ");
                String slName = sl.getName();
                slName = slName.endsWith("s") ? slName.substring(0, sl.getName().length() - 1) : slName;
                for (Node nd : nl)
                    output(nd, "- " + slName, level + 1, builder);
            }
        }
    }

    private String indent(int level) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < level; i++)
            for (int j = 0; j < NUM_SPACES_FOR_INDENT; j++)
                sb.append(" ");
        return sb.toString();
    }
}