package org.andromda.cartridges.jsf.component.html;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;
import org.apache.commons.beanutils.PropertyUtils;
import org.apache.commons.lang.ObjectUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.myfaces.component.html.ext.HtmlDataTable;
/**
* Extends the datatable and provides the ability to have a backing value: this is
* useful when submitting tables of information.
*
* @author Chad Brandon
*/
public class HtmlExtendedDataTable
extends HtmlDataTable
{
/**
* Overriden to provide population of the backingValue's items with the value's items (and
* updating the model afterwards).
*
* @see javax.faces.component.UIData#getValue()
*/
public Object getValue()
{
Object value = super.getValue();
Object backingValue = this.getBackingValue();
if (backingValue != null)
{
final Class valueType = this.getValueType();
final Class backingValueType = this.getBackingValueType();
if (valueType != backingValueType)
{
throw new IllegalArgumentException("The 'value' and 'backingValue' must be of the same type");
}
final String identifierColumnsString = this.getIdentifierColumns();
final String[] identifierColumns =
StringUtils.isBlank(identifierColumnsString) ? new String[0]
: StringUtils.trimToEmpty(identifierColumnsString).split(
"\\s*,\\s*");
// - handle collections
if (backingValue instanceof Collection)
{
if (!(backingValue instanceof List))
{
backingValue = new ArrayList((Collection)backingValue);
}
if (!(value instanceof List))
{
value = new ArrayList((Collection)value);
}
final List backingValues = (List)backingValue;
final List values = value != null ? (List)value : Collections.EMPTY_LIST;
for (final ListIterator iterator = backingValues.listIterator(); iterator.hasNext();)
{
final Object backingValueItem = iterator.next();
for (final Iterator valueIterator = values.iterator(); valueIterator.hasNext();)
{
final Object valueItem = valueIterator.next();
if (this.equal(
backingValueItem,
valueItem,
identifierColumns))
{
iterator.set(valueItem);
break;
}
}
}
value = backingValues;
}
// - handle arrays
else if (backingValue.getClass().isArray())
{
final Object[] backingValues = (Object[])backingValue;
final Object[] values = value != null ? (Object[])value : new Object[0];
for (int backingValueCtr = 0; backingValueCtr < backingValues.length; backingValueCtr++)
{
final Object backingValueItem = backingValues[backingValueCtr];
for (int valueCtr = 0; valueCtr < values.length; valueCtr++)
{
final Object valueItem = values[valueCtr];
if (this.equal(
backingValueItem,
valueItem,
identifierColumns))
{
backingValues[backingValueCtr] = valueItem;
break;
}
}
}
value = backingValues;
}
else
{
throw new IllegalArgumentException("The backing value must be a collection or array");
}
}
this.updateModelValue(value);
return value;
}
/**
* Indicates whether or not this objects are equal, first by comparing them directly for
* equality and if not equal in that sense compares the columns returned by {@link #getIdentifierColumns()}.
* @param object1 the first object.
* @param object2 the second object.
* @param properties if equality fails, then these properties are compared for equality (all of them must
* be equal or else this operation will return false).
* @return true/false
*/
private boolean equal(
final Object object1,
final Object object2,
final String[] properties)
{
boolean equal = object1 == object2;
if (!equal && object1 != null && object2 != null)
{
for (int ctr = 0; ctr < properties.length; ctr++)
{
final String property = properties[ctr];
if (property != null && property.trim().length() > 0)
{
final Object value1 = this.getProperty(
object1,
property);
final Object value2 = this.getProperty(
object2,
property);
if (value1 != null && value2 != null)
{
equal = value1.equals(value2);
if (!equal)
{
break;
}
}
}
}
}
return equal;
}
/**
* Updates the model (i.e. underlying managed bean's value).
*
* @param value the value from which to update the model.
*/
public void updateModelValue(final Object value)
{
final ValueBinding binding = getValueBinding(VALUE);
if (binding != null)
{
binding.setValue(
this.getFacesContext(),
value);
}
}
/**
* The value attribute.
*/
private static final String VALUE = "value";
/**
* Gets the type of the backing value attribute.
* @return the backing value's type or null if the backing value
* isn't defined.
*/
private Class getBackingValueType()
{
return this.getBindingType(BACKING_VALUE);
}
/**
* Gets the value's type attribute or null if value was not defined.
*
* @return the value's type or null if undefined.
*/
private Class getValueType()
{
return this.getBindingType(VALUE);
}
/**
* Gets the binding type given the attribute name.
*
* @param name the name of the component's attribute.
* @return the binding type or null if the binding wasn't found.
*/
private Class getBindingType(final String name)
{
Class type = null;
ValueBinding binding = getValueBinding(name);
if (binding != null)
{
final FacesContext context = this.getFacesContext();
type = binding.getType(context);
}
return type;
}
private Object getProperty(
final Object bean,
final String property)
{
try
{
return PropertyUtils.getProperty(
bean,
property);
}
catch (final Throwable throwable)
{
throw new RuntimeException(throwable);
}
}
private Object backingValue = null;
/**
* The attribute that stores the backing value.
*/
public static final String BACKING_VALUE = "backingValue";
/**
* Retrieves the backing value of this extended data table (the backing value contains
* the values which the result of the value attribute are compared against).
* @return
*/
protected Object getBackingValue()
{
if (this.backingValue == null)
{
final ValueBinding binding = this.getValueBinding(BACKING_VALUE);
this.backingValue = binding == null ? null : binding.getValue(getFacesContext());
}
return this.backingValue;
}
/**
* Stores the identifier columns attribute.
*/
private String identifierColumns;
/**
* The attrribute that stores the identifier columns.
*/
public static final String IDENTIFIER_COLUMNS = "identifierColumns";
/**
* Retrieves the identifier columns component attribute.
*
* @return the identifier columns component attribute.
*/
protected String getIdentifierColumns()
{
if (this.identifierColumns == null)
{
this.identifierColumns = (String)this.getAttributes().get(IDENTIFIER_COLUMNS);
if (this.identifierColumns == null)
{
final ValueBinding binding = this.getValueBinding(IDENTIFIER_COLUMNS);
this.identifierColumns =
binding == null ? null : ObjectUtils.toString(binding.getValue(getFacesContext()));
}
}
return this.identifierColumns;
}
}