com.codename1.processing.EvaluatorFactory Maven / Gradle / Ivy
/*
* Copyright (c) 2012, Eric Coolman, Codename One and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Codename One designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Codename One through http://www.codenameone.com/ if you
* need additional information or have any questions.
*/
package com.codename1.processing;
/**
* Internal class, do not use.
*
* Predicate Evaluator Factory, attempts to create a predicate evaluator given the expression.
*
* ie:
*
*
* [0] = IndexEvaluator
* [last()] = IndexEvaluator
* [@ponum=3] = AttributeEvaluator
* [lastname='Coolman'] = TextEvaluator
*
*
* @author Eric Coolman
*
*/
class EvaluatorFactory {
/**
* Construct an evaluator for a given predicate expression.
*
* @param text a full predicate expression.
* @return an Evaluator instance that can process the expression.
*/
public static Evaluator createEvaluator(String text) {
if (isNumeric(text)) {
return new IndexEvaluator(text);
} else if (text.startsWith("@")) {
return new AttributeEvaluator(text);
} else if (text.indexOf(IndexEvaluator.FUNC_LAST) != -1) {
return new IndexEvaluator(text);
} else if (text.indexOf(TextEvaluator.FUNC_TEXT) != -1) {
return new TextEvaluator(text);
} else if (text.indexOf(IndexEvaluator.FUNC_POSITION) != -1) {
return new IndexEvaluator(text);
} else if (text.startsWith("@")) {
return new AttributeEvaluator(text);
} else if (text.indexOf('%') != -1) {
return new ContainsEvaluator(text);
} else if (text.indexOf('=') != -1) {
return new TextEvaluator(text);
}
throw new IllegalStateException("Could not create a comparator for value: " + text);
}
/**
* Test if string contains only digits.
*
* @param text
* @return
*/
private static boolean isNumeric(String text) {
text = text.trim();
int tlen = text.length();
for (int i = 0; i < tlen; i++) {
if (Character.isDigit(text.charAt(i)) == false) {
return false;
}
}
return true;
}
}