mindbridge 2005/08/11 06:17:25
Modified: framework/src/java/org/apache/tapestry/components
ForBean.java
Log:
Further improved the algorithm of the For component
Revision Changes Path
1.6 +306 -307
jakarta-tapestry/framework/src/java/org/apache/tapestry/components/ForBean.java
Index: ForBean.java
===================================================================
RCS file:
/home/cvs/jakarta-tapestry/framework/src/java/org/apache/tapestry/components/ForBean.java,v
retrieving revision 1.5
retrieving revision 1.6
diff -u -r1.5 -r1.6
--- ForBean.java 10 Aug 2005 19:28:07 -0000 1.5
+++ ForBean.java 11 Aug 2005 13:17:25 -0000 1.6
@@ -21,7 +21,6 @@
import java.util.List;
import java.util.Map;
-import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.tapestry.IBinding;
import org.apache.tapestry.IForm;
import org.apache.tapestry.IMarkupWriter;
@@ -36,59 +35,48 @@
/**
* @author mb
*/
-public abstract class ForBean extends AbstractFormComponent
-{
+public abstract class ForBean extends AbstractFormComponent {
private static final char DESC_VALUE = 'V';
-
- private static final char DESC_PRIMARY_KEY = 'P';
-
- private static final String PARAMETER_SOURCE = "source";
-
- private static final String PARAMETER_FULL_SOURCE = "fullSource";
-
- // parameters
- public abstract Object getSource();
-
- public abstract Object getFullSource();
-
+ private static final char DESC_PRIMARY_KEY = 'P';
+
+ // parameters
+ public abstract Object getSource();
+ public abstract Object getFullSource();
public abstract String getElement();
-
public abstract boolean getVolatile();
-
public abstract Object getDefaultValue();
-
public abstract String getPrimaryKey();
-
public abstract IPrimaryKeyConverter getConverter();
-
public abstract String getKeyExpression();
// properties
public abstract Map getPrimaryKeyMap();
-
public abstract void setPrimaryKeyMap(Map primaryKeys);
- public abstract Map getSourceIteratorMap();
-
- public abstract void setSourceIteratorMap(Map sourceIteratorMap);
-
+ public abstract List getSourcePrimaryKeys();
+ public abstract void setSourcePrimaryKeys(List sourcePrimaryKeys);
+
+ public abstract List getSavedSourceData();
+ public abstract void setSavedSourceData(List sourceData);
+
+ public abstract Iterator getFullSourceIterator();
+ public abstract void setFullSourceIterator(Iterator fullSourceIterator);
+
// injects
public abstract DataSqueezer getDataSqueezer();
-
public abstract ValueConverter getValueConverter();
-
public abstract ExpressionEvaluator getExpressionEvaluator();
-
+
+
private Object _value;
-
private int _index;
-
private boolean _rendering;
/**
- * Gets the source binding and iterates through its values. For each, it
updates the value
- * binding and render's its wrapped elements.
- */
+ * Gets the source binding and iterates through
+ * its values. For each, it updates the value binding and render's its
wrapped elements.
+ *
+ **/
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
@@ -103,9 +91,9 @@
// Get the data to be iterated upon. Store in form if needed.
Iterator dataSource = getData(cycle, form);
-
- // Do not iterate if dataSource is null.
- // The dataSource was either not convertable to Iterator, or was
empty.
+
+ // Do not iterate if dataSource is null.
+ // The dataSource was either not convertable to Iterator, or was
empty.
if (dataSource == null)
return;
@@ -119,12 +107,12 @@
while (dataSource.hasNext())
{
- // Get current value
+ // Get current value
_value = dataSource.next();
// Update output component parameters
updateOutputParameters();
-
+
// Render component
if (element != null)
{
@@ -146,325 +134,341 @@
_value = null;
}
}
-
+
+
/**
- * Returns a list with the values to be iterated upon. The list is
obtained in different ways: -
- * If the component is not located in a form or 'volatile' is set to
true, then the simply the
- * values passed to 'source' are returned (same as Foreach) - If the
component is in a form, and
- * the form is rewinding, the values stored in the form are returned --
rewind is then always
- * the same as render. - If the component is in a form, and the form is
being rendered, the
- * values are stored in the form as Hidden fields.
+ * Returns a list with the values to be iterated upon.
+ *
+ * The list is obtained in different ways:
+ * - If the component is not located in a form or 'volatile' is set to
true,
+ * then the simply the values passed to 'source' are returned (same as
Foreach)
+ * - If the component is in a form, and the form is rewinding, the
values stored
+ * in the form are returned -- rewind is then always the same as
render.
+ * - If the component is in a form, and the form is being rendered, the
values
+ * are stored in the form as Hidden fields.
*
- * @param cycle
- * The current request cycle
- * @param form
- * The form within which the component is located (if any)
+ * @param cycle The current request cycle
+ * @param form The form within which the component is located (if any)
* @return An iterator with the values to be cycled upon
- */
- private Iterator getData(IRequestCycle cycle, IForm form)
- {
+ **/
+ private Iterator getData(IRequestCycle cycle, IForm form) {
if (form == null || getVolatile())
- return getSource(PARAMETER_SOURCE);
-
+ return getSourceData().iterator();
+
String name = form.getElementId(this);
if (cycle.isRewinding())
- return getStoredData(cycle, name);
-
- return storeSourceData(form, name);
+ return getStoredData(cycle, name);
+ return storeSourceData(form, name);
}
-
+
/**
- * Returns an [EMAIL PROTECTED] Iterator} containing the values provided
by the identified source binding.
- *
- * @param parameter
- * The name of the source binding
- * @return an iterator with the bound values. null if the parameter is
not bound or the
- * conversion cannot be performed
- */
- protected Iterator getSource(String parameter)
- {
- IBinding binding = getBinding(parameter);
- if (binding == null)
- return null;
-
- Object data = binding.getObject();
- return (Iterator) getValueConverter().coerceValue(data,
Iterator.class);
+ * Returns a [EMAIL PROTECTED] java.util.List} containing the values
provided
+ * by the identified source binding.
+ *
+ * @return a list with the values to iterate upon.
+ * null if conversion cannot be performed.
+ **/
+ protected List getSourceData()
+ {
+ List sourceData = getSavedSourceData();
+ if (sourceData == null) {
+ Object source = getSource();
+ sourceData = (List) getValueConverter().coerceValue(source,
List.class);
+ setSavedSourceData(sourceData);
+ }
+ return sourceData;
+ }
+
+
+ protected Iterator getSources(String parameter)
+ {
+ IBinding binding = getBinding(parameter);
+ if (binding == null)
+ return null;
+
+ Object data = binding.getObject();
+ return (Iterator) getValueConverter().coerceValue(data,
Iterator.class);
}
-
+
/**
- * Returns a list of the values stored as Hidden fields in the form. A
conversion is performed
- * if the primary key of the value is stored.
- *
- * @param cycle
- * The current request cycle
- * @param name
- * The name of the HTTP parameter whether the values
- * @return an iterator with the values stored in the provided Hidden
fields
- */
+ * Returns a list of the values stored as Hidden fields in the form.
+ * A conversion is performed if the primary key of the value is stored.
+ *
+ * @param cycle The current request cycle
+ * @param name The name of the HTTP parameter whether the values
+ * @return an iterator with the values stored in the provided Hidden
fields
+ **/
protected Iterator getStoredData(IRequestCycle cycle, String name)
{
String[] submittedPrimaryKeys = cycle.getParameters(name);
String pkDesc = submittedPrimaryKeys[0];
// unsqueeze data
- List data = new ArrayList(submittedPrimaryKeys.length - 1);
- List pks = new ArrayList(submittedPrimaryKeys.length - 1);
- for (int i = 1; i < submittedPrimaryKeys.length; i++)
- {
- String stringRep = submittedPrimaryKeys[i];
- try
- {
- Object value = getDataSqueezer().unsqueeze(stringRep);
- data.add(value);
- if (i <= pkDesc.length() && pkDesc.charAt(i - 1) ==
DESC_PRIMARY_KEY)
- pks.add(value);
- }
- catch (Exception ex)
- {
- throw new ApplicationRuntimeException(Tapestry.format(
- "For.unable-to-convert-string",
- stringRep), this, null, ex);
- }
- }
-
- // update the binding with the list of primary keys
- IBinding primaryKeysBinding = getBinding("primaryKeys");
- if (primaryKeysBinding != null)
- primaryKeysBinding.setObject(pks);
+ List data = new ArrayList(submittedPrimaryKeys.length-1);
- // convert from primary keys to data
- for (int i = 0; i < data.size(); i++)
- {
- if (i <= pkDesc.length() && pkDesc.charAt(i) == DESC_PRIMARY_KEY)
- {
- Object pk = data.get(i);
- Object value = getValueFromPrimaryKey(pk);
- data.set(i, value);
- }
- }
+ List pks = null;
+ IBinding primaryKeysBinding = getBinding("primaryKeys");
+ if (primaryKeysBinding != null)
+ pks = new ArrayList(submittedPrimaryKeys.length-1);
+ for (int i = 1; i < submittedPrimaryKeys.length; i++) {
+ String stringRep = submittedPrimaryKeys[i];
+ Object value = getDataSqueezer().unsqueeze(stringRep);
+ data.add(value);
+ if (primaryKeysBinding != null && i <= pkDesc.length()
&& pkDesc.charAt(i-1) == DESC_PRIMARY_KEY)
+ pks.add(value);
+ }
+ // update the binding with the list of primary keys
+ if (primaryKeysBinding != null)
+ primaryKeysBinding.setObject(pks);
+
+ // convert from primary keys to data
+ for (int i = 0; i < data.size(); i++) {
+ if (i <= pkDesc.length() && pkDesc.charAt(i) ==
DESC_PRIMARY_KEY) {
+ Object pk = data.get(i);
+ Object value = getValueFromPrimaryKey(pk);
+ data.set(i, value);
+ }
+ }
+
return data.iterator();
}
-
+
/**
- * Stores the provided data in the form and then returns the data as an
iterator. If the primary
- * key of the value can be determined, then that primary key is saved
instead.
- *
- * @param form
- * The form where the data will be stored
- * @param name
- * The name under which the data will be stored
- * @return an iterator with the bound values stored in the form
- */
+ * Stores the provided data in the form and then returns the data as an
iterator.
+ * If the primary key of the value can be determined,
+ * then that primary key is saved instead.
+ *
+ * @param form The form where the data will be stored
+ * @param name The name under which the data will be stored
+ * @return an iterator with the bound values stored in the form
+ **/
protected Iterator storeSourceData(IForm form, String name)
{
- Iterator iteratorSource = getSource(PARAMETER_SOURCE);
- if (iteratorSource == null)
- return null;
-
- // extract primary keys from data
- StringBuffer pkDesc = new StringBuffer();
- List data = new ArrayList();
- List pks = new ArrayList();
- while (iteratorSource.hasNext())
- {
- Object value = iteratorSource.next();
- data.add(value);
-
- Object pk = getPrimaryKeyFromValue(value);
- if (pk == null)
- {
- pk = value;
- pkDesc.append(DESC_VALUE);
- }
- else
- pkDesc.append(DESC_PRIMARY_KEY);
- pks.add(pk);
- }
-
- // store primary keys
- form.addHiddenValue(name, pkDesc.toString());
- for (Iterator it = pks.iterator(); it.hasNext();)
- {
- Object pk = it.next();
- try
- {
- String stringRep = getDataSqueezer().squeeze(pk);
- form.addHiddenValue(name, stringRep);
- }
- catch (Exception ex)
- {
- throw new ApplicationRuntimeException(Tapestry.format(
- "For.unable-to-convert-value",
- pk), this, null, ex);
- }
- }
-
- return data.iterator();
+ List sourceData = getSourceData();
+ if (sourceData == null)
+ return null;
+
+ List sourcePrimaryKeys = generateSourcePrimaryKeys();
+ if (sourcePrimaryKeys == null)
+ return null;
+
+ // store primary keys
+ form.addHiddenValue(name, sourcePrimaryKeys.get(0).toString());
+ for (int i = 1; i < sourcePrimaryKeys.size(); i++) {
+ Object pk = sourcePrimaryKeys.get(i);
+ String stringRep = getDataSqueezer().squeeze(pk);
+ form.addHiddenValue(name, stringRep);
+ }
+
+ return sourceData.iterator();
}
/**
- * Returns the primary key of the given value. Uses the 'keyExpression'
or the 'converter' (if
- * either is provided).
- *
- * @param value
- * The value from which the primary key should be extracted
- * @return The primary key of the value, or null if such cannot be
extracted.
+ * Converts the values in the 'source' parameter to primary keys
+ * and returns a list containing the primary keys or the values
themselves
+ * if a primary key cannot be extracted. The first element of the array
is a
+ * string that shows whether a particular element is a primary key or a
value.
+ * The method also stores the evaluated primary keys in a map that can
be used
+ * to determine the value that a particular primary key represents.
+ *
+ * @return an array consisting of the primary keys of the source values
or
+ * the values themselves if a primary key cannot be found. The first
element
+ * of the array is a string describing whether a particular element is
+ * a primary key or a value.
*/
- private Object getPrimaryKeyFromValue(Object value)
+ private List generateSourcePrimaryKeys()
{
- Object primaryKey = null;
-
- String keyExpression = getKeyExpression();
- if (keyExpression != null)
- primaryKey = getExpressionEvaluator().read(value, keyExpression);
-
- if (primaryKey == null)
- {
- IPrimaryKeyConverter converter = getConverter();
- if (converter != null)
- primaryKey = converter.getPrimaryKey(value);
- }
-
- return primaryKey;
+ // check if the result is already cached to avoid evaluating again
+ List sourcePrimaryKeys = getSourcePrimaryKeys();
+ if (sourcePrimaryKeys != null)
+ return sourcePrimaryKeys;
+
+ List sourceData = getSourceData();
+ if (sourceData == null)
+ return null;
+
+ Map primaryKeyMap = getPrimaryKeyMap();
+ if (primaryKeyMap == null)
+ primaryKeyMap = new HashMap();
+
+ // extract primary keys from data
+ StringBuffer pkDesc = new StringBuffer(sourceData.size());
+ sourcePrimaryKeys = new ArrayList(sourceData.size()+1);
+ sourcePrimaryKeys.add(pkDesc);
+ for (Iterator it = sourceData.iterator(); it.hasNext();) {
+ Object value = it.next();
+
+ Object pk = getPrimaryKeyFromValue(value);
+ if (pk == null) {
+ pkDesc.append(DESC_VALUE);
+ pk = value;
+ }
+ else {
+ pkDesc.append(DESC_PRIMARY_KEY);
+ primaryKeyMap.put(pk, value);
+ }
+ sourcePrimaryKeys.add(pk);
+ }
+
+ setSourcePrimaryKeys(sourcePrimaryKeys);
+ setPrimaryKeyMap(primaryKeyMap);
+
+ return sourcePrimaryKeys;
}
-
+
/**
- * Returns a value that corresponds to the provided primary key. Uses
either the 'keyExpression'
- * if provided
+ * Iterates over the fullSource parameter until a value with a matching
primary key is found.
+ * The primary keys generated and the fullSource iterator are stored in
properties
+ * to avoid repeated evaluation.
*
- * @param primaryKey
- * @return
+ * @param primaryKey the primary key to be matched
+ * @param fullSource the provided list of objects
+ * @return an object with a matching primary key, or null if such is not
found
*/
- private Object getValueFromPrimaryKey(Object primaryKey)
+ private Object findPrimaryKeyMatchInFullSource(Object primaryKey, Object
fullSource)
{
- Object value = null;
-
- // if keyExpression is defined, try to get the object in that way
- String keyExpression = getKeyExpression();
- if (keyExpression != null)
- value = getValueFromExpressionPrimaryKeys(keyExpression,
primaryKey);
-
- if (value == null)
- {
- IPrimaryKeyConverter converter = getConverter();
- if (converter != null)
- value = converter.getValue(primaryKey);
- }
-
- if (value == null)
- value = getDefaultValue();
-
- return value;
+ Map primaryKeyMap = getPrimaryKeyMap();
+ if (primaryKeyMap == null)
+ primaryKeyMap = new HashMap();
+
+ Iterator it = getFullSourceIterator();
+ if (it == null) {
+ it = (Iterator)
getValueConverter().coerceValue(fullSource, Iterator.class);
+ if (it == null)
+ it = Collections.EMPTY_LIST.iterator();
+ }
+
+ try {
+ while (it.hasNext()) {
+ Object sourceValue = it.next();
+ if (sourceValue == null)
+ continue;
+
+ Object sourcePrimaryKey =
getPrimaryKeyFromValue(sourceValue);
+ if (sourcePrimaryKey != null)
+ primaryKeyMap.put(sourcePrimaryKey,
sourceValue);
+
+ if (primaryKey.equals(sourcePrimaryKey)) {
+ return sourceValue;
+ }
+ }
+
+ return null;
+ }
+ finally {
+ setFullSourceIterator(it);
+ setPrimaryKeyMap(primaryKeyMap);
+ }
}
+
+ /**
+ * Returns the primary key of the given value.
+ * Uses the 'keyExpression' or the 'converter' (if either is provided).
+ *
+ * @param value The value from which the primary key should be extracted
+ * @return The primary key of the value, or null if such cannot be
extracted.
+ */
+ private Object getPrimaryKeyFromValue(Object value) {
+ if (value == null)
+ return null;
+
+ Object primaryKey = null;
+
+ String keyExpression = getKeyExpression();
+ if (keyExpression != null)
+ primaryKey = getExpressionEvaluator().read(value,
keyExpression);
+
+ if (primaryKey == null) {
+ IPrimaryKeyConverter converter = getConverter();
+ if (converter != null)
+ primaryKey = converter.getPrimaryKey(value);
+ }
- private Object getValueFromExpressionPrimaryKeys(String keyExpression,
Object primaryKey)
- {
- Object value = null;
-
- Map primaryKeys = getPrimaryKeyMap();
- if (primaryKeys == null)
- primaryKeys = new HashMap();
- else
- {
- value = primaryKeys.get(primaryKey);
- if (value != null)
- return value;
- }
-
- // Iterate over the elements in 'source' and 'fullSource' until a
primary key match is found
- value = findPrimaryKeyMatch(primaryKey, PARAMETER_SOURCE);
- if (value == null)
- value = findPrimaryKeyMatch(primaryKey, PARAMETER_FULL_SOURCE);
-
- return value;
+ return primaryKey;
}
+
+ /**
+ * Returns a value that corresponds to the provided primary key.
+ * Uses the 'keyExpression' or the 'converter' (if either is provided).
+ * If 'keyExpression' is defined, it extracts the primary keys of all
values
+ * in 'source' until a match is found. If there is no match, it does the
same
+ * with 'fullSource'. If that does not help either, 'converter' is used.
+ * Finally, the 'defaultValue' is returned as a last resort.
+ *
+ * @param primaryKey The primary key that identifies the value
+ * @return A value with an identical primary key, or null if such is not
found.
+ */
+ private Object getValueFromPrimaryKey(Object primaryKey) {
+ Object value = null;
- private Object findPrimaryKeyMatch(Object primaryKey, String parameter)
- {
- ExpressionEvaluator evaluator = getExpressionEvaluator();
- String keyExpression = getKeyExpression();
-
- Map primaryKeys = getPrimaryKeyMap();
- if (primaryKeys == null)
- primaryKeys = new HashMap();
-
- Map sourceIteratorMap = getSourceIteratorMap();
- if (sourceIteratorMap == null)
- sourceIteratorMap = new HashMap();
-
- Iterator it = (Iterator) sourceIteratorMap.get(parameter);
- if (it == null)
- {
- it = getSource(parameter);
- if (it == null)
- it = Collections.EMPTY_LIST.iterator();
- }
-
- try
- {
- while (it.hasNext())
- {
- Object sourceValue = it.next();
- Object sourcePrimaryKey = evaluator.read(sourceValue,
keyExpression);
- if (sourcePrimaryKey != null)
- primaryKeys.put(sourcePrimaryKey, sourceValue);
+ generateSourcePrimaryKeys();
+
+ Map primaryKeyMap = getPrimaryKeyMap();
+ if (primaryKeyMap != null)
+ value = primaryKeyMap.get(primaryKey);
+
+ if (value == null) {
+ // if fullSource is defined, try to get the object in that way
+ Object fullSource = getFullSource();
+ if (fullSource != null)
+ value = findPrimaryKeyMatchInFullSource(primaryKey,
fullSource);
+ }
+
+ if (value == null) {
+ IPrimaryKeyConverter converter = getConverter();
+ if (converter != null)
+ value = converter.getValue(primaryKey);
+ }
- if (primaryKey.equals(sourcePrimaryKey))
- {
- return sourceValue;
- }
- }
+ if (value == null)
+ value = getDefaultValue();
- return null;
- }
- finally
- {
- sourceIteratorMap.put(parameter, it);
- setSourceIteratorMap(sourceIteratorMap);
- setPrimaryKeyMap(primaryKeys);
- }
+ return value;
}
-
+
+ /**
+ * Updates the index and value output parameters if bound.
+ */
private void updateOutputParameters()
{
- IBinding indexBinding = getBinding("index");
- if (indexBinding != null)
- indexBinding.setObject(new Integer(_index));
-
- IBinding valueBinding = getBinding("value");
- if (valueBinding != null)
- valueBinding.setObject(_value);
+ IBinding indexBinding = getBinding("index");
+ if (indexBinding != null)
+ indexBinding.setObject(new Integer(_index));
+
+ IBinding valueBinding = getBinding("value");
+ if (valueBinding != null)
+ valueBinding.setObject(_value);
}
-
+
/**
- * Returns the most recent value extracted from the source parameter.
- *
- * @throws org.apache.tapestry.ApplicationRuntimeException
- * if the Foreach is not currently rendering.
- */
+ * Returns the most recent value extracted from the source parameter.
+ *
+ * @throws org.apache.tapestry.ApplicationRuntimeException if the For
is not currently rendering.
+ *
+ **/
public final Object getValue()
{
if (!_rendering)
throw Tapestry.createRenderOnlyPropertyException(this, "value");
-
+
return _value;
}
/**
- * The index number, within the [EMAIL PROTECTED] #getSource() source},
of the the current value.
+ * The index number, within the [EMAIL PROTECTED] #getSource() source},
of the
+ * the current value.
*
- * @throws org.apache.tapestry.ApplicationRuntimeException
- * if the Foreach is not currently rendering.
- * @since 2.2
- */
-
+ * @throws org.apache.tapestry.ApplicationRuntimeException if the For
is not currently rendering.
+ *
+ **/
+
public int getIndex()
{
if (!_rendering)
throw Tapestry.createRenderOnlyPropertyException(this, "index");
-
+
return _index;
}
@@ -473,12 +477,7 @@
return false;
}
- // Do nothing in those methods, but make the JVM happy
- protected void renderFormComponent(IMarkupWriter writer, IRequestCycle
cycle)
- {
- }
-
- protected void rewindFormComponent(IMarkupWriter writer, IRequestCycle
cycle)
- {
- }
+ // Do nothing in those methods, but make the JVM happy
+ protected void renderFormComponent(IMarkupWriter writer, IRequestCycle
cycle) { }
+ protected void rewindFormComponent(IMarkupWriter writer, IRequestCycle
cycle) { }
}
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