/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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.apache.cocoon.forms.binding;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import org.apache.avalon.framework.logger.Logger;
import org.apache.cocoon.forms.formmodel.Repeater;
import org.apache.cocoon.forms.formmodel.Widget;
import org.apache.cocoon.forms.datatype.convertor.ConversionResult;
import org.apache.commons.collections.ListUtils;
import org.apache.commons.jxpath.JXPathContext;
import org.apache.commons.jxpath.Pointer;
/**
* RepeaterJXPathBinding provides an implementation of a {@link Binding}
* that allows for bidirectional binding of a repeater-widget to/from
* repeating structures in the back-end object model.
*
* @version CVS $Id: RepeaterJXPathBinding.java,v 1.9 2004/05/11 08:22:54 bruno Exp $
*/
public class RepeaterJXPathBinding extends JXPathBindingBase {
private final String repeaterId;
private final String repeaterPath;
private final String rowPath;
private final String rowPathForInsert;
private final JXPathBindingBase rowBinding;
private final JXPathBindingBase insertRowBinding;
private final JXPathBindingBase deleteRowBinding;
private final ComposedJXPathBindingBase identityBinding;
/**
* Constructs RepeaterJXPathBinding
*/
public RepeaterJXPathBinding(
JXPathBindingBuilderBase.CommonAttributes commonAtts,
String repeaterId, String repeaterPath, String rowPath,
String rowPathForInsert,
JXPathBindingBase[] childBindings, JXPathBindingBase insertBinding,
JXPathBindingBase[] deleteBindings, JXPathBindingBase[] identityBindings) {
super(commonAtts);
this.repeaterId = repeaterId;
this.repeaterPath = repeaterPath;
this.rowPath = rowPath;
this.rowPathForInsert = rowPathForInsert;
this.rowBinding = new ComposedJXPathBindingBase(
JXPathBindingBuilderBase.CommonAttributes.DEFAULT,
childBindings);
this.rowBinding.setParent(this);
this.insertRowBinding = insertBinding;
if (this.insertRowBinding != null) {
this.insertRowBinding.setParent(this);
}
if (deleteBindings != null) {
this.deleteRowBinding = new ComposedJXPathBindingBase(
JXPathBindingBuilderBase.CommonAttributes.DEFAULT,
deleteBindings);
this.deleteRowBinding.setParent(this);
} else {
this.deleteRowBinding = null;
}
this.identityBinding = new ComposedJXPathBindingBase(
JXPathBindingBuilderBase.CommonAttributes.DEFAULT,
identityBindings);
if (this.identityBinding != null) {
this.identityBinding.setParent(this);
}
}
/**
* Binds the unique-id of the repeated rows, and narrows the context on
* objectModelContext and Repeater to the repeated rows before handing
* over to the actual binding-children.
*/
public void doLoad(Widget frmModel, JXPathContext jxpc)
throws BindingException {
// Find the repeater
Repeater repeater = (Repeater) selectWidget(frmModel, this.repeaterId);
if (repeater == null) {
throw new BindingException("The repeater with the ID [" + this.repeaterId
+ "] referenced in the binding does not exist in the form definition.");
}
repeater.removeRows();
int initialSize = repeater.getSize();
// build a jxpath iterator for pointers
JXPathContext repeaterContext =
jxpc.getRelativeContext(jxpc.getPointer(this.repeaterPath));
Iterator rowPointers = repeaterContext.iteratePointers(this.rowPath);
//iterate through it
while (rowPointers.hasNext()) {
// create a new row, take that as the frmModelSubContext
Repeater.RepeaterRow thisRow;
if (initialSize > 0) {
thisRow = repeater.getRow(--initialSize);
} else {
thisRow = repeater.addRow();
}
// make a jxpath ObjectModelSubcontext on the iterated element
Pointer jxp = (Pointer)rowPointers.next();
JXPathContext rowContext = repeaterContext.getRelativeContext(jxp);
// hand it over to children
this.identityBinding.loadFormFromModel(thisRow, rowContext);
this.rowBinding.loadFormFromModel(thisRow, rowContext);
}
if (getLogger().isDebugEnabled())
getLogger().debug("done loading rows " + toString());
}
/**
* Uses the mapped identity of each row to detect if rows have been
* updated, inserted or removed. Depending on what happened the appropriate
* child-bindings are allowed to visit the narrowed contexts.
*/
public void doSave(Widget frmModel, JXPathContext jxpc)
throws BindingException {
// Find the repeater
Repeater repeater = (Repeater) selectWidget(frmModel, this.repeaterId);
// and his context
JXPathContext repeaterContext =
jxpc.getRelativeContext(jxpc.getPointer(this.repeaterPath));
// create set of updatedRowIds
Set updatedRows = new HashSet();
//create list of rows to insert at end
List rowsToInsert = new ArrayList();
// iterate rows in the form model...
int formRowCount = repeater.getSize();
for (int i = 0; i < formRowCount; i++) {
Repeater.RepeaterRow thisRow = repeater.getRow(i);
// Get the identity
List identity = getIdentity(thisRow);
if (hasNonNullElements(identity)) {
// iterate nodes to find match
Iterator rowPointers = repeaterContext.iteratePointers(this.rowPath);
boolean found = false;
while (rowPointers.hasNext()) {
Pointer jxp = (Pointer) rowPointers.next();
JXPathContext rowContext = repeaterContext.getRelativeContext(jxp);
List contextIdentity = getIdentity(rowContext);
if (ListUtils.isEqualList(identity, contextIdentity)) {
// match! --> bind to children
this.rowBinding.saveFormToModel(thisRow, rowContext);
// --> store rowIdValue in list of updatedRowIds
updatedRows.add(identity);
found = true;
break;
}
}
if (!found) {
// this is a new row
rowsToInsert.add(thisRow);
// also add it to the updated row id's so that this row doesn't get deleted
updatedRows.add(identity);
}
} else {
// if there is no value to determine the identity --> this is a new row
rowsToInsert.add(thisRow);
}
}
// Iterate again nodes for deletion
Iterator rowPointers = repeaterContext.iteratePointers(this.rowPath);
List rowsToDelete = new ArrayList();
while (rowPointers.hasNext()) {
Pointer jxp = (Pointer)rowPointers.next();
JXPathContext rowContext = repeaterContext.getRelativeContext((Pointer)jxp.clone());
List contextIdentity = getIdentity(rowContext);
// check if the identity of the rowContext is in the updated rows
// if not --> bind for delete
if (!isIdentityInUpdatedRows(updatedRows, contextIdentity)) {
rowsToDelete.add(rowContext);
}
}
if (rowsToDelete.size() > 0) {
if (this.deleteRowBinding != null) {
// run backwards through the list, so that we don't get into
// trouble by shifting indexes
for (int i = rowsToDelete.size() - 1; i >= 0; i--) {
this.deleteRowBinding.saveFormToModel(frmModel,
rowsToDelete.get(i));
}
} else {
if (getLogger().isWarnEnabled()) {
getLogger().warn(
"RepeaterBinding has detected rows to delete, " +
"but misses the <on-delete-row> binding to do it."
);
}
}
}
// count how many we have now
int indexCount = 1;
rowPointers = repeaterContext.iteratePointers(this.rowPathForInsert);
while (rowPointers.hasNext()) {
rowPointers.next();
indexCount++;
}
// end with rows to insert (to make sure they don't get deleted!)
if (rowsToInsert.size() > 0) {
if (this.insertRowBinding != null) {
Iterator rowIterator = rowsToInsert.iterator();
//register the factory!
while (rowIterator.hasNext()) {
Repeater.RepeaterRow thisRow = (Repeater.RepeaterRow)rowIterator.next();
// Perform the insert row binding.
this.insertRowBinding.saveFormToModel(repeater, repeaterContext);
// --> create the path to let the context be created
Pointer newRowContextPointer = repeaterContext.createPath(
this.rowPathForInsert + "[" + indexCount + "]");
JXPathContext newRowContext =
repeaterContext.getRelativeContext(newRowContextPointer);
if (getLogger().isDebugEnabled()) {
getLogger().debug("inserted row at " + newRowContextPointer.asPath());
}
// + rebind to children for update
this.rowBinding.saveFormToModel(thisRow, newRowContext);
getLogger().debug("bound new row");
indexCount++;
}
} else {
if (getLogger().isWarnEnabled()) {
getLogger().warn("RepeaterBinding has detected rows to insert, but misses "
+ "the <on-insert-row> binding to do it.");
}
}
}
if (getLogger().isDebugEnabled()) {
getLogger().debug("done saving rows " + toString());
}
}
/**
* Tests if an identity is already contained in a Set of identities.
* @param identitySet the Set of identities.
* @param identity the identity that is tested if it is already in the Set.
* @return true if the Set contains the identity, false otherwise.
*/
private boolean isIdentityInUpdatedRows(Set identitySet, List identity) {
Iterator iter = identitySet.iterator();
while (iter.hasNext()) {
List identityFromSet = (List)iter.next();
if (ListUtils.isEqualList(identityFromSet, identity)) {
return true;
}
}
return false;
}
/**
* Tests if any of the elements in a List is not null.
* @param list
* @return
*/
private boolean hasNonNullElements(List list) {
Iterator iter = list.iterator();
while (iter.hasNext()) {
if (iter.next() != null) {
return true;
}
}
return false;
}
/**
* Get the identity of the given row context. That's infact a list of all
* the values of the fields in the bean or XML that constitute the identity.
* @param rowContext
* @return List the identity of the row context
*/
private List getIdentity(JXPathContext rowContext) {
List identity = new ArrayList();
JXPathBindingBase[] childBindings = this.identityBinding.getChildBindings();
if (childBindings != null) {
int size = childBindings.length;
for (int i = 0; i < size; i++) {
ValueJXPathBinding vBinding = (ValueJXPathBinding)childBindings[i];
Object value = rowContext.getValue(vBinding.getXPath());
if (value != null && vBinding.getConvertor() != null) {
if (value instanceof String) {
ConversionResult conversionResult = vBinding.getConvertor().convertFromString(
(String)value, vBinding.getConvertorLocale(), null);
if (conversionResult.isSuccessful())
value = conversionResult.getResult();
else
value = null;
} else {
if (getLogger().isWarnEnabled()) {
getLogger().warn("Convertor ignored on backend-value " +
"which isn't of type String.");
}
}
}
identity.add(value);
}
}
return identity;
}
/**
* Get the identity of the given row. That's infact a list of all the values
* of the fields in the form model that constitute the identity.
* @param thisRow
* @return List the identity of the row
*/
private List getIdentity(Repeater.RepeaterRow row) {
List identity = new ArrayList();
JXPathBindingBase[] childBindings = this.identityBinding.getChildBindings();
if (childBindings != null) {
int size = childBindings.length;
for (int i = 0; i < size; i++) {
String fieldId = ((ValueJXPathBinding)childBindings[i]).getFieldId();
Widget widget = row.getChild(fieldId);
Object value = widget.getValue();
identity.add(value);
}
}
return identity;
}
public String toString() {
return "RepeaterJXPathBinding [widget=" + this.repeaterId +
", xpath=" + this.repeaterPath + "]";
}
public void enableLogging(Logger logger) {
super.enableLogging(logger);
if (this.deleteRowBinding != null) {
this.deleteRowBinding.enableLogging(logger);
}
if (this.insertRowBinding != null) {
this.insertRowBinding.enableLogging(logger);
}
this.rowBinding.enableLogging(logger);
if (this.identityBinding != null) {
this.identityBinding.enableLogging(logger);
}
}
}