/**
* Copyright 2010 JBoss Inc
*
* 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 org.drools.ide.common.server.util;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;
import org.mvel2.MVEL;
/**
* Use mvel to load up map/list of valid items for fields - used by the Guided rule editor.
*/
public class DataEnumLoader {
private final List<String> errors;
private final Map<String, String[]> data;
/**
* This is the source of the asset, which is an MVEL map (minus the outer "[") of course.
*/
public DataEnumLoader(String mvelSource) {
errors = new ArrayList<String>();
this.data = loadEnum(mvelSource);
}
private Map<String, String[]> loadEnum(String mvelSource) {
if (mvelSource == null || (mvelSource.trim().equals( "" ))) {
return Collections.emptyMap();
}
if (mvelSource.startsWith("=")) {
mvelSource = mvelSource.substring(1);
} else {
mvelSource = "[ " + addCommasForNewLines(mvelSource) + " ]";
}
final Object mvelData;
try {
mvelData = MVEL.eval(mvelSource, new HashMap<String, Object>());
} catch (RuntimeException e) {
addError("Unable to load enumeration data.");
addError(e.getMessage());
addError("Error type: " + e.getClass().getName());
return Collections.emptyMap();
}
if (!(mvelData instanceof Map<?, ?>)) {
addError("The expression is not a map, it is a " + mvelData.getClass().getName());
return Collections.emptyMap();
}
Map<String, Object> map = (Map<String, Object>) mvelData;
Map<String, String[]> newMap = new HashMap<String, String[]>();
for (Map.Entry<String, Object> entry: map.entrySet()) {
String key = entry.getKey();
Object list = entry.getValue();
if (!(list instanceof List<?> || list instanceof String)) {
if (list == null) {
addError("The item with " + key + " is null.");
} else {
addError("The item with " + key + " is not a list or a string, it is a " + list.getClass().getName());
}
return Collections.emptyMap();
} else if (list instanceof String) {
newMap.put(key, new String[] {(String)list});
} else {
List<?> items = (List<?>) list;
String[] newItems = new String[items.size()];
for (int i = 0; i < items.size(); i++) {
Object listItem = items.get(i);
if (!(listItem instanceof String)) {
newItems[i] = listItem.toString();
} else {
newItems[i] = (String) listItem;
}
}
newMap.put(key, newItems);
}
}
return newMap;
}
public static String addCommasForNewLines(String mvelSource) {
StringTokenizer st = new StringTokenizer(mvelSource, "\r\n");
StringBuilder buf = new StringBuilder();
while(st.hasMoreTokens()) {
String line = st.nextToken().trim();
if (st.hasMoreTokens() && line.endsWith( "," )) {
buf.append( line );
} else {
buf.append( line );
if (st.hasMoreTokens()) {
buf.append( "," );
}
}
if (st.hasMoreTokens()) {
buf.append( "\n" );
}
}
return buf.toString();
}
private void addError(String string) {
this.errors.add(string);
}
/**
* Return a list of any errors found.
*/
public List<String> getErrors() {
return this.errors;
}
public boolean hasErrors() {
return this.errors.size() > 0;
}
/**
* Return the map of Fact.field to List (of Strings).
*/
public Map<String, String[]> getData() {
return this.data;
}
}