org.mvel2.integration.impl.BaseVariableResolverFactory Maven / Gradle / Ivy

Go to download
/**
 * MVEL 2.0
 * Copyright (C) 2007 The Codehaus
 * Mike Brock, Dhanji Prasanna, John Graham, Mark Proctor
 *
 * 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.mvel2.integration.impl;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.mvel2.UnresolveablePropertyException;
import org.mvel2.integration.VariableResolver;
import org.mvel2.integration.VariableResolverFactory;

/**
 * Use this class to extend you own VariableResolverFactories. It contains most of the baseline implementation needed
 * for the vast majority of integration needs.
 */
public abstract class BaseVariableResolverFactory implements VariableResolverFactory {

    protected Map variableResolvers = new HashMap();
    protected VariableResolverFactory nextFactory;

    protected int indexOffset = 0;
    protected String[] indexedVariableNames;
    protected VariableResolver[] indexedVariableResolvers;

    private boolean tiltFlag;

    public VariableResolverFactory getNextFactory() {
        return nextFactory;
    }

    public VariableResolverFactory setNextFactory(VariableResolverFactory resolverFactory) {
        return nextFactory = resolverFactory;
    }

    public VariableResolver getVariableResolver(String name) {
        if (isResolveable(name)) {
            if (variableResolvers.containsKey(name)) {
                return variableResolvers.get(name);
            } else if (nextFactory != null) {
                return nextFactory.getVariableResolver(name);
            }
        }

        throw new UnresolveablePropertyException("unable to resolve variable '" + name + "'");
    }

    public boolean isNextResolveable(String name) {
        return nextFactory != null && nextFactory.isResolveable(name);
    }

    public void appendFactory(VariableResolverFactory resolverFactory) {
        if (nextFactory == null) {
            nextFactory = resolverFactory;
        } else {
            VariableResolverFactory vrf = nextFactory;
            while (vrf.getNextFactory() != null) {
                vrf = vrf.getNextFactory();
            }
            vrf.setNextFactory(nextFactory);
        }
    }

    public void insertFactory(VariableResolverFactory resolverFactory) {
        if (nextFactory == null) {
            nextFactory = resolverFactory;
        } else {
            resolverFactory.setNextFactory(nextFactory = resolverFactory);
        }
    }

    public Set getKnownVariables() {
        if (nextFactory == null) {
            return new HashSet(variableResolvers.keySet());
            //   return new HashSet(0);
        } else {
            HashSet vars = new HashSet(variableResolvers.keySet());
            vars.addAll(nextFactory.getKnownVariables());
            return vars;
        }
    }

    public VariableResolver createIndexedVariable(int index, String name, Object value) {
        if (nextFactory != null) {
            return nextFactory.createIndexedVariable(index - indexOffset, name, value);
        } else {
            throw new RuntimeException("cannot create indexed variable: " + name + "(" + index + "). operation not supported by resolver: "
                    + this.getClass().getName());
        }
    }

    public VariableResolver getIndexedVariableResolver(int index) {
        if (nextFactory != null) {
            return nextFactory.getIndexedVariableResolver(index - indexOffset);
        } else {
            throw new RuntimeException(
                    "cannot access indexed variable: " + index + ".  operation not supported by resolver: " + this.getClass().getName());
        }
    }

    public VariableResolver createIndexedVariable(int index, String name, Object value, Class type) {
        if (nextFactory != null) {
            return nextFactory.createIndexedVariable(index - indexOffset, name, value, type);
        } else {
            throw new RuntimeException("cannot access indexed variable: " + name + "(" + index
                    + ").  operation not supported by resolver.: " + this.getClass().getName());
        }
    }

    public Map getVariableResolvers() {
        return variableResolvers;
    }

    public void setVariableResolvers(Map variableResolvers) {
        this.variableResolvers = variableResolvers;
    }

    public String[] getIndexedVariableNames() {
        return indexedVariableNames;
    }

    public void setIndexedVariableNames(String[] indexedVariableNames) {
        this.indexedVariableNames = indexedVariableNames;
    }

    public int variableIndexOf(String name) {
        if (indexedVariableNames != null) for (int i = 0; i < indexedVariableNames.length; i++) {
            if (name.equals(indexedVariableNames[i])) {
                return i;
            }
        }
        return -1;
    }

    public VariableResolver setIndexedVariableResolver(int index, VariableResolver resolver) {
        if (indexedVariableResolvers == null) {
            return (indexedVariableResolvers = new VariableResolver[indexedVariableNames.length])[index - indexOffset] = resolver;
        } else {
            return indexedVariableResolvers[index - indexOffset] = resolver;
        }
    }

    public boolean isIndexedFactory() {
        return false;
    }

    public boolean tiltFlag() {
        return tiltFlag;
    }

    public void setTiltFlag(boolean tiltFlag) {
        this.tiltFlag = tiltFlag;
        if (nextFactory != null) nextFactory.setTiltFlag(tiltFlag);
    }
}