org.obiba.magma.beans.BeanPropertyVariableValueSource.java Source code

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Here is the source code for org.obiba.magma.beans.BeanPropertyVariableValueSource.java

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/*******************************************************************************
 * Copyright 2008(c) The OBiBa Consortium. All rights reserved.
 *
 * This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package org.obiba.magma.beans;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

import org.obiba.magma.MagmaRuntimeException;
import org.obiba.magma.Value;
import org.obiba.magma.ValueSet;
import org.obiba.magma.ValueType;
import org.obiba.magma.Variable;
import org.obiba.magma.VariableValueSource;
import org.obiba.magma.VectorSource;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.InvalidPropertyException;
import org.springframework.beans.NullValueInNestedPathException;
import org.springframework.beans.PropertyAccessorFactory;
import org.springframework.util.Assert;

import com.google.common.base.Function;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;

/**
 * Connects a {@code Variable} to a bean property.
 */
public class BeanPropertyVariableValueSource implements VariableValueSource {

    private Variable variable;

    private Class<?> beanClass;

    private String propertyPath;

    public BeanPropertyVariableValueSource(Variable variable, Class<?> beanClass, String propertyPath) {
        Assert.notNull(variable, "variable cannot be null");
        Assert.notNull(beanClass, "beanClass cannot be null");
        Assert.notNull(propertyPath, "propertyPath cannot be null");

        this.variable = variable;
        this.beanClass = beanClass;
        this.propertyPath = propertyPath;
    }

    @Override
    public Variable getVariable() {
        return variable;
    }

    @Nonnull
    @Override
    public ValueType getValueType() {
        return variable.getValueType();
    }

    @Override
    @Nonnull
    public Value getValue(ValueSet valueSet) {
        Object bean = ((BeanValueSet) valueSet).resolve(beanClass, valueSet, variable);

        if (bean == null) {
            return variable.isRepeatable() ? getValueType().nullSequence() : getValueType().nullValue();
        }

        if (variable.isRepeatable()) {
            Iterable<Value> values = Iterables.transform((Iterable<?>) bean, new Function<Object, Value>() {
                @Override
                public Value apply(Object bean) {
                    Object object = getPropertyValue(propertyPath,
                            PropertyAccessorFactory.forBeanPropertyAccess(bean));
                    return getValueType().valueOf(object);
                }
            });
            return getValueType().sequenceOf(ImmutableList.copyOf(values));
        } else {
            Object object = getPropertyValue(propertyPath, PropertyAccessorFactory.forBeanPropertyAccess(bean));
            return getValueType().valueOf(object);
        }
    }

    @Nullable
    @Override
    public VectorSource asVectorSource() {
        return null;
    }

    @Nullable
    protected Object getPropertyValue(String propertyPath, BeanWrapper bw) {
        try {
            return bw.getPropertyValue(propertyPath);
        } catch (NullValueInNestedPathException e) {
            return null;
        } catch (InvalidPropertyException e) {
            throw new MagmaRuntimeException("Invalid definition of variable " + getVariable().getName()
                    + ". Cannot obtain value for property '" + e.getPropertyName() + "' on bean of class "
                    + e.getBeanClass(), e);
        }
    }
}