com.frank.search.solr.core.query.IfFunction.java Source code

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Here is the source code for com.frank.search.solr.core.query.IfFunction.java

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/*
 * Copyright 2012 - 2013 the original author or authors.
 *
 * 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 com.frank.search.solr.core.query;

import org.springframework.util.Assert;

/**
 * Implementation of {@code if(value|field|function,trueValue,falseValue)}
 * 
 * @author Christoph Strobl
 * @since 1.1
 */
public class IfFunction extends AbstractFunction {

    private static final String OPERATION = "if";

    private IfFunction() {
        super();
    }

    /**
     * Creates new {@link IfFunction.Builder} for creating {@link IfFunction}
     * 
     * @param condition
     * @return
     */
    public static Builder when(Object condition) {
        return new Builder(condition);
    }

    public static Builder when(Field field) {
        Assert.notNull(field, "Field cannot be 'null' in if clause.");

        return when(field.getName());
    }

    public static Builder when(String fieldname) {
        Assert.hasText(fieldname, "Fieldname cannot be 'null' for if clause.");

        return new Builder(fieldname);
    }

    public static Builder when(Function function) {
        Assert.notNull(function, "Function cannot be 'null' for if clause.");

        return new Builder(function);
    }

    @Override
    public String getOperation() {
        return OPERATION;
    }

    public static class Builder {

        private IfFunction function;

        public Builder(Object condition) {
            Assert.notNull(condition, "Condition cannot be 'null' for if operation");

            function = new IfFunction();
            function.addArgument(condition);
        }

        /**
         * @param value
         * @return
         */
        public Builder then(Object value) {
            Assert.notNull(value, "True value cannot be 'null' for if operation.");

            function.addArgument(value);
            return this;
        }

        /**
         * @param value
         * @return
         */
        public IfFunction otherwise(Object value) {
            Assert.notNull(value, "False value cannot be 'null' for if operation.");

            function.addArgument(value);
            return function;
        }
    }

}