package org.drools.template.parser;
/*
* Copyright 2005 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.
*/
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.drools.core.util.StringUtils;
import org.drools.template.model.Condition;
import org.drools.template.model.Rule;
import org.drools.template.model.SnippetBuilder;
/**
*
* @author <a href="mailto:stevearoonie@gmail.com">Steven Williams</a>
*
* The default column condition for a rule template to be generated. If the
* conditon starts with "!" then the template will only be generated if the
* column condition does not exist. If there is no condition string then the
* template will be generated only if the column contains a value. The condition
* can be any valid rule condition.
*/
class DefaultTemplateColumn implements TemplateColumn {
private static final Pattern COLUMN_PATTERN = Pattern
.compile("^(!?)([a-zA-Z0-9_]*)(\\[([0-9]+)\\])?\\s*(.*)");
private boolean notCondition;
private String columnName;
private String condition;
private TemplateContainer templateContainer;
private int index = -1;
DefaultTemplateColumn(TemplateContainer tc, String columnString) {
templateContainer = tc;
Matcher matcher = COLUMN_PATTERN.matcher(columnString);
if (!matcher.matches())
throw new IllegalArgumentException("column " + columnString
+ " is not valid");
notCondition = !StringUtils.isEmpty(matcher.group(1));
columnName = matcher.group(2);
String indexString = matcher.group(4);
condition = matcher.group(5);
if (!StringUtils.isEmpty(indexString)) {
index = Integer.parseInt(indexString);
}
}
private void createCellCondition(final Rule rule) {
StringBuffer conditionString = new StringBuffer();
Column column = templateContainer.getColumn(columnName);
column.getCondition(condition, index);
if (notCondition) {
conditionString.append("not ");
}
conditionString.append("exists ");
conditionString.append(column.getCondition(condition, index));
SnippetBuilder snip = new SnippetBuilder(conditionString.toString());
Condition condition = new Condition();
condition.setSnippet(snip.build(columnName));
rule.addCondition(condition);
}
private void createColumnCondition(final Rule rule, final String value) {
SnippetBuilder colSnip = new SnippetBuilder(
"$param : Column(name == \"$param\")");
Condition colCondition = new Condition();
colCondition.setSnippet(colSnip.build(value));
rule.addCondition(colCondition);
}
public void addCondition(Rule rule) {
createColumnCondition(rule, columnName);
createCellCondition(rule);
}
public String getName() {
return columnName;
}
public boolean isNotCondition() {
return notCondition;
}
public String getCondition() {
return condition;
}
}