/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 javax.servlet.jsp.tagext;
import java.util.Hashtable;
The (translation-time only) attribute/value information for a tag instance.
TagData is only used as an argument to the isValid, validate, and
getVariableInfo methods of TagExtraInfo, which are invoked at
translation time.
/**
* The (translation-time only) attribute/value information for a tag instance.
*
* <p>
* TagData is only used as an argument to the isValid, validate, and
* getVariableInfo methods of TagExtraInfo, which are invoked at
* translation time.
*/
public class TagData implements Cloneable {
Distinguished value for an attribute to indicate its value
is a request-time expression (which is not yet available because
TagData instances are used at translation-time).
/**
* Distinguished value for an attribute to indicate its value
* is a request-time expression (which is not yet available because
* TagData instances are used at translation-time).
*/
public static final Object REQUEST_TIME_VALUE = new Object();
Constructor for TagData.
A typical constructor may be
static final Object[][] att = {{"connection", "conn0"}, {"id", "query0"}};
static final TagData td = new TagData(att);
All values must be Strings except for those holding the
distinguished object REQUEST_TIME_VALUE.
Params: - atts – the static attribute and values. May be null.
/**
* Constructor for TagData.
*
* <p>
* A typical constructor may be
* <pre>
* static final Object[][] att = {{"connection", "conn0"}, {"id", "query0"}};
* static final TagData td = new TagData(att);
* </pre>
*
* All values must be Strings except for those holding the
* distinguished object REQUEST_TIME_VALUE.
* @param atts the static attribute and values. May be null.
*/
public TagData(Object[] atts[]) {
if (atts == null) {
attributes = new Hashtable<>();
} else {
attributes = new Hashtable<>(atts.length);
}
if (atts != null) {
for (int i = 0; i < atts.length; i++) {
attributes.put((String) atts[i][0], atts[i][1]);
}
}
}
Constructor for a TagData.
If you already have the attributes in a hashtable, use this
constructor.
Params: - attrs – A hashtable to get the values from.
/**
* Constructor for a TagData.
*
* If you already have the attributes in a hashtable, use this
* constructor.
*
* @param attrs A hashtable to get the values from.
*/
public TagData(Hashtable<String, Object> attrs) {
this.attributes = attrs;
}
The value of the tag's id attribute.
Returns: the value of the tag's id attribute, or null if no such
attribute was specified.
/**
* The value of the tag's id attribute.
*
* @return the value of the tag's id attribute, or null if no such
* attribute was specified.
*/
public String getId() {
return getAttributeString(TagAttributeInfo.ID);
}
The value of the attribute.
If a static value is specified for an attribute that accepts a
request-time attribute expression then that static value is returned,
even if the value is provided in the body of a <jsp:attribute>
action. The distinguished object REQUEST_TIME_VALUE is only returned if
the value is specified as a request-time attribute expression
or via the <jsp:attribute> action with a body that contains
dynamic content (scriptlets, scripting expressions, EL expressions,
standard actions, or custom actions). Returns null if the attribute
is not set.
Params: - attName – the name of the attribute
Returns: the attribute's value
/**
* The value of the attribute.
* If a static value is specified for an attribute that accepts a
* request-time attribute expression then that static value is returned,
* even if the value is provided in the body of a <jsp:attribute>
* action. The distinguished object REQUEST_TIME_VALUE is only returned if
* the value is specified as a request-time attribute expression
* or via the <jsp:attribute> action with a body that contains
* dynamic content (scriptlets, scripting expressions, EL expressions,
* standard actions, or custom actions). Returns null if the attribute
* is not set.
*
* @param attName the name of the attribute
* @return the attribute's value
*/
public Object getAttribute(String attName) {
return attributes.get(attName);
}
Set the value of an attribute.
Params: - attName – the name of the attribute
- value – the value.
/**
* Set the value of an attribute.
*
* @param attName the name of the attribute
* @param value the value.
*/
public void setAttribute(String attName,
Object value) {
attributes.put(attName, value);
}
Get the value for a given attribute.
Params: - attName – the name of the attribute
Throws: - ClassCastException – if attribute value is not a String
Returns: the attribute value string
/**
* Get the value for a given attribute.
*
* @param attName the name of the attribute
* @return the attribute value string
* @throws ClassCastException if attribute value is not a String
*/
public String getAttributeString(String attName) {
Object o = attributes.get(attName);
if (o == null) {
return null;
}
return (String) o;
}
Enumerates the attributes.
Returns: An enumeration of the attributes in a TagData
/**
* Enumerates the attributes.
*
*@return An enumeration of the attributes in a TagData
*/
public java.util.Enumeration<String> getAttributes() {
return attributes.keys();
}
// private data
private final Hashtable<String, Object> attributes; // the tagname/value map
}