com.chiorichan.factory.interpreters.GSPInterpreter.java Source code

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Here is the source code for com.chiorichan.factory.interpreters.GSPInterpreter.java

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/**
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 * Copyright 2015 Chiori-chan. All Right Reserved.
 * 
 * @author Chiori Greene
 * @email chiorigreene@gmail.com
 */
package com.chiorichan.factory.interpreters;

import groovy.lang.Script;

import java.io.ByteArrayOutputStream;
import java.io.IOException;

import org.apache.commons.lang3.StringUtils;

import com.chiorichan.factory.EvalMetaData;
import com.chiorichan.factory.ShellFactory;
import com.chiorichan.lang.EvalFactoryException;

/**
 * SeaShell for handling GSP files.
 * ie. Embedded Groovy Files
 * 
 * sample:
 * <p>
 * This is plain html<% print ", with a twist of groovy. Today's date: " + date("") %>.
 * </p>
 */
public class GSPInterpreter implements Interpreter {
    private static final String MARKER_START = "<%";
    private static final String MARKER_END = "%>";

    @Override
    public String[] getHandledTypes() {
        return new String[] { "embedded", "gsp", "jsp", "chi" };
    }

    @Override
    public Object eval(EvalMetaData meta, String fullFile, ShellFactory shellFactory, ByteArrayOutputStream bs)
            throws Exception {
        int fullFileIndex = 0;
        String[] dontStartWith = new String[] { "println", "print", "echo", "def", "import", "if", "for", "do", "}",
                "else", "//", "/*", "\n", "\r" };

        StringBuilder output = new StringBuilder();

        while (fullFileIndex < fullFile.length()) {
            int startIndex = fullFile.indexOf(MARKER_START, fullFileIndex);
            if (-1 != startIndex) {
                // Append all the simple text until the marker

                String fragment = escapeFragment(fullFile.substring(fullFileIndex, startIndex));
                if (!fragment.isEmpty())
                    output.append(fragment);

                int endIndex = fullFile.indexOf(MARKER_END, Math.max(startIndex, fullFileIndex));

                if (endIndex == -1)
                    throw new EvalFactoryException(new IOException("Marker `<%` was not closed after line "
                            + (StringUtils.countMatches(output.toString(), "\n") + 1)
                            + ", please check your source file and try again."), shellFactory);

                fragment = fullFile.substring(startIndex + MARKER_START.length(), endIndex);

                boolean appendPrint = true;

                for (String s : dontStartWith)
                    if (fragment.trim().startsWith(s) || fragment.startsWith(s) || fragment.trim().isEmpty())
                        appendPrint = false;

                if (appendPrint)
                    fragment = "print " + fragment;

                if (!fragment.isEmpty())
                    output.append(fragment + "; ");

                // Position index after end marker
                fullFileIndex = endIndex + MARKER_END.length();
            } else {
                String fragment = escapeFragment(fullFile.substring(fullFileIndex));

                if (!fragment.isEmpty())
                    output.append(fragment);

                // Position index after the end of the file
                fullFileIndex = fullFile.length() + 1;
            }
        }

        meta.source = output.toString();

        return interpret(shellFactory, output.toString(), meta);
    }

    public String escapeFragment(String fragment) {
        String brackets = "\"\"\"";

        fragment = fragment.replace("\\$", "$");
        fragment = fragment.replace("$", "\\$");

        if (fragment.endsWith("\""))
            brackets = "'''";

        return "print " + brackets + fragment + brackets + "; ";
    }

    private Object interpret(ShellFactory shellFactory, String scriptText, EvalMetaData meta) {
        Script script = shellFactory.makeScript(scriptText, meta);

        Object o = script.run();

        return (o == null) ? "" : o;
    }
}