ParameterProcessorComponent.java

/*
 * #%L
 * Alfresco Records Management Module
 * %%
 * Copyright (C) 2005 - 2016 Alfresco Software Limited
 * %%
 * This file is part of the Alfresco software.
 * -
 * If the software was purchased under a paid Alfresco license, the terms of
 * the paid license agreement will prevail.  Otherwise, the software is
 * provided under the following open source license terms:
 * -
 * Alfresco is free software: you can redistribute it and/or modify
 * it under the terms of 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.
 * -
 * Alfresco 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.
 * -
 * You should have received a copy of the GNU Lesser General Public License
 * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
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package org.alfresco.repo.action.parameter;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.alfresco.error.AlfrescoRuntimeException;
import org.alfresco.service.cmr.action.ParameterizedItem;
import org.alfresco.service.cmr.action.ParameterizedItemDefinition;
import org.alfresco.service.cmr.repository.NodeRef;

/**
 * Parameter processor component
 *
 * @author Roy Wetherall
 * @since 2.1
 */
public class ParameterProcessorComponent implements ParameterSubstitutionSuggester
{
    /** regex used to parse parameters */
    private static final String REG_EX_OLD = "\\$\\{([^\\$\\{]+)\\}";
    private static final String REG_EX = "\\{([^\\{]+)\\}";

    /** registry of parameter processors */
    private Map<String, ParameterProcessor> processors = new HashMap<String, ParameterProcessor>(5);
    private List<ParameterSubstitutionSuggester> subtitutionSuggesterProcessors = new ArrayList<ParameterSubstitutionSuggester>(5);

    /**
     * Register parameter processor
     *
     * @param processor
     */
    public void register(ParameterProcessor processor)
    {
        this.processors.put(processor.getName(), processor);
        if(processor instanceof ParameterSubstitutionSuggester)
        {
            this.subtitutionSuggesterProcessors.add((ParameterSubstitutionSuggester)processor);
        }
    }

    /**
     *
     * @param ruleItem
     * @param ruleItemDefinition
     * @param actionedUponNodeRef
     */
    public void process(ParameterizedItem ruleItem, ParameterizedItemDefinition ruleItemDefinition, NodeRef actionedUponNodeRef)
    {
        for (Map.Entry<String, Serializable> entry : ruleItem.getParameterValues().entrySet())
        {
            String parameterName = entry.getKey();
            Object parameterValue = entry.getValue();

            // only sub string property values
            if (parameterValue instanceof String)
            {
                // set the updated parameter value
                ruleItem.setParameterValue(parameterName, process((String)parameterValue, actionedUponNodeRef));
            }
        }
    }

    /**
     * Process the value for substitution within the context of the provided node.
     *
     * @param value     value
     * @param nodeRef   node reference
     * @return String   resulting value
     */
    public String process(String value, NodeRef nodeRef)
    {
        return process(process(value, nodeRef, REG_EX_OLD), nodeRef, REG_EX);
    }

    public String process(String value, NodeRef nodeRef, String regExp)
    {
        // match the substitution pattern
        Pattern patt = Pattern.compile(regExp);
        Matcher m = patt.matcher(value);
        StringBuffer sb = new StringBuffer(value.length());

        while (m.find())
        {
          String text = m.group(1);

          // lookup parameter processor to use
          ParameterProcessor processor = lookupProcessor(text);
          if (processor == null)
          {
              throw new AlfrescoRuntimeException("A parameter processor has not been found for the substitution string " + text);
          }
          else
          {
              // process each substitution value
              text = processor.process(text, nodeRef);
          }

          // append new value
          m.appendReplacement(sb, Matcher.quoteReplacement(text));
        }
        m.appendTail(sb);
        return sb.toString();
    }

    /**
     * Return a list of substitution suggestions for the passed string fragment.
     *
     * @param subtitutionFragment  Text fragment to search on.
     * @return A list of substitutions that match the substitution fragment.
     */
    public List<String> getSubstitutionSuggestions(final String substitutionFragment)
    {
        List<String> suggestions = new ArrayList<String>();
        for (ParameterSubstitutionSuggester suggestor : this.subtitutionSuggesterProcessors)
        {
            suggestions.addAll(suggestor.getSubstitutionSuggestions(substitutionFragment.toLowerCase()));
        }
        return suggestions;
    }

    /**
     * Look up parameter processor
     *
     * @param value
     * @return
     */
    private ParameterProcessor lookupProcessor(String value)
    {
        ParameterProcessor result = null;

        if (value != null && !value.isEmpty())
        {
            String[] values = value.split("\\.", 2);
            if (values.length != 0)
            {
                // get the processor from the registered map
                result = processors.get(values[0]);
            }
        }

        return result;
    }
}