ScriptHelp.java

/*! ******************************************************************************
 *
 * Pentaho Data Integration
 *
 * Copyright (C) 2002-2013 by Pentaho : http://www.pentaho.com
 *
 *******************************************************************************
 *
 * 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.
 *
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package org.pentaho.di.ui.trans.steps.script;

import java.io.InputStream;
import java.util.Hashtable;

import org.pentaho.di.core.exception.KettleXMLException;
import org.pentaho.di.core.xml.XMLHandler;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class ScriptHelp {

  private static Document dom;
  private static Hashtable<String, String> hatFunctionsList;

  public ScriptHelp( String strFileName ) throws KettleXMLException {
    super();
    xparseXmlFile( strFileName );
    buildFunctionList();

  }

  public Hashtable<String, String> getFunctionList() {
    return hatFunctionsList;
  }

  private static void buildFunctionList() {
    hatFunctionsList = new Hashtable<String, String>();
    NodeList nlFunctions = dom.getElementsByTagName( "jsFunction" );
    for ( int i = 0; i < nlFunctions.getLength(); i++ ) {
      String strFunctionName = nlFunctions.item( i ).getAttributes().getNamedItem( "name" ).getNodeValue();
      Node elType = ( (Element) nlFunctions.item( i ) ).getElementsByTagName( "type" ).item( 0 );
      String strType = "";
      if ( elType.hasChildNodes() ) {
        strType = elType.getFirstChild().getNodeValue();
      }
      NodeList nlFunctionArgs = ( (Element) nlFunctions.item( i ) ).getElementsByTagName( "argument" );
      for ( int j = 0; j < nlFunctionArgs.getLength(); j++ ) {
        String strFunctionArgs = nlFunctionArgs.item( j ).getFirstChild().getNodeValue();
        hatFunctionsList.put( strFunctionName + "(" + strFunctionArgs + ")", strType );
      }
      if ( nlFunctionArgs.getLength() == 0 ) {
        hatFunctionsList.put( strFunctionName + "()", strType );
      }
    }
  }

  public String getSample( String strFunctionName, String strFunctionNameWithArgs ) {
    String sRC = "// Sorry, no Script available for " + strFunctionNameWithArgs;

    NodeList nl = dom.getElementsByTagName( "jsFunction" );
    for ( int i = 0; i < nl.getLength(); i++ ) {
      if ( nl.item( i ).getAttributes().getNamedItem( "name" ).getNodeValue().equals( strFunctionName ) ) {
        Node elSample = ( (Element) nl.item( i ) ).getElementsByTagName( "sample" ).item( 0 );
        if ( elSample.hasChildNodes() ) {
          return ( elSample.getFirstChild().getNodeValue() );
        }
      }
    }
    return sRC;
  }

  private static void xparseXmlFile( String strFileName ) throws KettleXMLException {
    try {
      InputStream is = ScriptHelp.class.getResourceAsStream( strFileName );
      int c;
      StringBuilder buffer = new StringBuilder();
      while ( ( c = is.read() ) != -1 ) {
        buffer.append( (char) c );
      }
      is.close();
      dom = XMLHandler.loadXMLString( buffer.toString() );
    } catch ( Exception e ) {
      throw new KettleXMLException( "Unable to read script values help file from file [" + strFileName + "]", e );
    }
  }
}