Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2020 gvSIG Association.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 *

 * This program 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 for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.fmap.dal.store.jdbc2.spi.expressionbuilder.formatters;

import java.util.Objects;

import org.apache.commons.lang3.StringUtils;

import org.gvsig.expressionevaluator.ExpressionBuilder;

import org.gvsig.expressionevaluator.ExpressionBuilder.Function;

import org.gvsig.expressionevaluator.ExpressionBuilder.Value;

import org.gvsig.expressionevaluator.ExpressionUtils;

import org.gvsig.expressionevaluator.Formatter;

import org.gvsig.expressionevaluator.SymbolTable;

import org.gvsig.fmap.dal.SQLBuilder;

import static org.gvsig.fmap.dal.store.jdbc2.spi.JDBCSQLBuilderBase.PROP_SYMBOLTABLE;

import static org.gvsig.expressionevaluator.ExpressionBuilder.FUNCTION_$CONSTANT;

/**

 *

 * @author jjdelcerro

 */

public class $Constant implements Formatter<Value> {

    private final SQLBuilder sqlbuilder;

    private final Formatter<Value> formatter;

    public $Constant(SQLBuilder sqlbuilder, Formatter<Value> formatter) {

        this.sqlbuilder = sqlbuilder;

        this.formatter = formatter;

    }

    @Override

    public boolean canApply(ExpressionBuilder.Value value) {

        if (value instanceof ExpressionBuilder.Function) { 

            return StringUtils.equalsIgnoreCase(FUNCTION_$CONSTANT, ((Function) value).name());

        }

        return false;

    }

    @Override

    public String format(Value value) {

        return resolve(this.sqlbuilder.expression(), this.formatter, value);

    }

    public static boolean isConstant(Value value) {

        if( value instanceof ExpressionBuilder.Constant) {

            return true;

        } 

        return value instanceof ExpressionBuilder.Function && 

               StringUtils.equalsIgnoreCase(((ExpressionBuilder.Function)value).name(),FUNCTION_$CONSTANT);

    }

    public static String resolve(Value value) {

        ExpressionBuilder builder = ExpressionUtils.createExpressionBuilder();

        return resolve(builder, null, value);

    }

    public static String resolve(ExpressionBuilder builder, Formatter<Value> formatter, Value value) {

        if( value instanceof ExpressionBuilder.Constant) {

            Object x = ((ExpressionBuilder.Constant)value).value();

            return builder.constant(x).toString(formatter);

        } else if( value instanceof ExpressionBuilder.Function && 

                StringUtils.equalsIgnoreCase(((ExpressionBuilder.Function)value).name(),FUNCTION_$CONSTANT) ) {

            SymbolTable symbolTable = (SymbolTable) value.getProperty(PROP_SYMBOLTABLE);

            Object x = ExpressionUtils.evaluate(symbolTable, value.toString());

            return builder.constant(x).toString(formatter);

        } 

        throw new RuntimeException("Expected constant value or $$CONSTANT function ("+Objects.toString(value)+").");

    }

}