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<?xml version="1.0"?>
<document url="struts-logic.html" authors="false">
<properties>
<title>The Struts Framework Project - Logic Tags</title>
</properties>
<body>
<taglib>
<tlibversion>1.0</tlibversion>
<jspversion>1.1</jspversion>
<shortname>logic</shortname>
<display-name>Struts Logic Tags</display-name>
<uri>http://jakarta.apache.org/struts/tags-logic</uri>
<info>
<p>This tag library contains tags that are useful in managing conditional
generation of output text, looping over object collections for
repetitive generation of output text, and application flow management.</p>
<p>For tags that do value comparisons (<code>equal</code>,
<code>greaterEqual</code>, <code>greaterThan</code>, <code>lessEqual</code>,
<code>lessThan</code>, <code>notEqual</code>), the following rules apply:</p>
<ul>
<li>The specified value is examined. If it can be converted successfully
to a <code>double</code> or a <code>long</code>, it is assumed that the
ultimate comparison will be numeric (either floating point or integer).
Otherwise, a String comparison will be performed.</li>
<li>The variable to be compared to is retrieved, based on the selector
attribute(s) (<code>cookie</code>, <code>header</code>,
<code>name</code>, <code>parameter</code>, <code>property</code>)
present on this tag. It will be converted to the appropriate type
for the comparison, as determined above.</li>
<li>If the specified variable or property returns null, it will be
coerced to a zero-length string before the comparison occurs.</li>
<li>The specific comparison for this tag will be performed, and the nested
body content of this tag will be evaluated if the comparison returns
a <code>true</code> result.</li>
</ul>
<p>For tags that do substring matching (<code>match</code>,
<code>notMatch</code>), the following rules apply:</p>
<ul>
<li>The specified variable is retrieved, based on the selector attribute(s)
(<code>cookie</code>, <code>header</code>, <code>name</code>,
<code>parameter</code>, <code>property</code>) present on this tag.
The variable is converted to a String, if necessary.</li>
<li>A request time exception will be thrown if the specified variable
cannot be retrieved, or has a null value.</li>
<li>The specified value is checked for existence as a substring of the
variable, in the position specified by the <code>location</code>
attribute, as follows: at the beginning (if location is set to
<code>start</code>), at the end (if location is set to
<code>end</code>), or anywhere (if location is not specified).</li>
</ul>
<p>Many of the tags in this tag library will throw a
<code>JspException</code> at runtime when they are utilized incorrectly
(such as when you specify an invalid combination of tag attributes). JSP
allows you to declare an "error page" in the <code>&lt;%@ page %&gt;</code>
directive. If you wish to process the actual exception that caused the
problem, it is passed to the error page as a request attribute under key
<code>org.apache.struts.action.EXCEPTION</code>.</p>
</info>
<tag>
<name>empty</name>
<summary>
Evaluate the nested body content of this tag if the requested variable is
either <code>null</code> or an empty string.
</summary>
<tagclass>org.apache.struts.taglib.logic.EmptyTag</tagclass>
<bodycontent>JSP</bodycontent>
<since>Struts 1.1</since>
<info>
<p>This tag evaluates its nested body content only if the specified value
is either absent (i.e. <code>null</code>), an empty string (i.e. a
<code>java.lang.String</code> with a length of zero), or an empty
<code>java.util.Collection</code> or <code>java.util.Map</code> (tested by
the .isEmpty() method on the respective interface).</p>
<p>
<strong>JSTL</strong>: The equivalent JSTL tag is &lt;c:if&gt; using the
<code>empty</code> operator. For example,
<br/>
<code>
&lt;c:if test="${empty sessionScope.myBean.myProperty}"&gt;
do something
&lt;/c:if&gt;
</code>
</p>
</info>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the JSP bean specified by this
attribute, if <code>property</code> is not specified, or the value
of the specified property of this bean, if <code>property</code>
is specified.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the property (of the bean specified
by the <code>name</code> attribute) specified by this attribute.
The property reference can be simple, nested, and/or indexed.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
</tag>
<tag>
<name>equal</name>
<summary>
Evaluate the nested body content of this tag if the requested
variable is equal to the specified value.
</summary>
<tagclass>org.apache.struts.taglib.logic.EqualTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Compares the variable specified by one of the selector attributes
against the specified constant value. The nested body content of this
tag is evaluated if the variable and value are <strong>equal</strong>.
</p>
</info>
<attribute>
<name>cookie</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the cookie whose
name is specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>header</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the header whose
name is specified by this attribute. The name match is performed
in a case insensitive manner.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the JSP bean specified by this
attribute, if <code>property</code> is not specified, or the value
of the specified property of this bean, if <code>property</code>
is specified.</p>
</info>
</attribute>
<attribute>
<name>parameter</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the first, or only, value of the
request parameter specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the property (of the bean specified
by the <code>name</code> attribute) specified by this attribute.
The property reference can be simple, nested, and/or indexed.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>value</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The constant value to which the variable, specified by other
attribute(s) of this tag, will be compared.</p>
</info>
</attribute>
</tag>
<tag>
<name>forward</name>
<summary>
Forward control to the page specified by the specified ActionForward
entry.
</summary>
<tagclass>org.apache.struts.taglib.logic.ForwardTag</tagclass>
<bodycontent>empty</bodycontent>
<info>
<p>Performs a <code>PageContext.forward()</code> or
<code>HttpServletResponse.sendRedirect()</code> call for the global
<code>ActionForward</code> entry for the specified name. URL
rewriting will occur automatically if a redirect is performed.</p>
</info>
<attribute>
<name>name</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>
The logical name of the global <code>ActionForward</code> entry
that identifies the destination, and forwarding approach, to be used.
<strong>Note</strong>: forwarding to Tiles definitions is not supported
from this tag. You should forward to them from an Action subclass.
</p>
</info>
</attribute>
</tag>
<tag>
<name>greaterEqual</name>
<summary>
Evaluate the nested body content of this tag if the requested
variable is greater than or equal to the specified value.
</summary>
<tagclass>org.apache.struts.taglib.logic.GreaterEqualTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Compares the variable specified by one of the selector attributes
against the specified constant value. The nested body content of this
tag is evaluated if the variable is <strong>greater than or equal</strong>
to the value.</p>
</info>
<attribute>
<name>cookie</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the cookie whose
name is specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>header</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the header whose
name is specified by this attribute. The name match is performed
in a case insensitive manner.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the JSP bean specified by this
attribute, if <code>property</code> is not specified, or the value
of the specified property of this bean, if <code>property</code>
is specified.</p>
</info>
</attribute>
<attribute>
<name>parameter</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the first, or only, value of the
request parameter specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the property (of the bean specified
by the <code>name</code> attribute) specified by this attribute.
The property reference can be simple, nested, and/or indexed.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>value</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The constant value to which the variable, specified by other
attribute(s) of this tag, will be compared.</p>
</info>
</attribute>
</tag>
<tag>
<name>greaterThan</name>
<summary>
Evaluate the nested body content of this tag if the requested
variable is greater than the specified value.
</summary>
<tagclass>org.apache.struts.taglib.logic.GreaterThanTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Compares the variable specified by one of the selector attributes
against the specified constant value. The nested body content of this
tag is evaluated if the variable is <strong>greater than</strong>
the value.</p>
</info>
<attribute>
<name>cookie</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the cookie whose
name is specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>header</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the header whose
name is specified by this attribute. The name match is performed
in a case insensitive manner.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the JSP bean specified by this
attribute, if <code>property</code> is not specified, or the value
of the specified property of this bean, if <code>property</code>
is specified.</p>
</info>
</attribute>
<attribute>
<name>parameter</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the first, or only, value of the
request parameter specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the property (of the bean specified
by the <code>name</code> attribute) specified by this attribute.
The property reference can be simple, nested, or indexed.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>value</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The constant value to which the variable, specified by other
attribute(s) of this tag, will be compared.</p>
</info>
</attribute>
</tag>
<tag>
<name>iterate</name>
<summary>
Repeat the nested body content of this tag over a specified collection.
</summary>
<tagclass>org.apache.struts.taglib.logic.IterateTag</tagclass>
<teiclass>org.apache.struts.taglib.logic.IterateTei</teiclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Repeats the nested body content of this tag once for every element
of the specified collection, which must be an <code>Iterator</code>,
a <code>Collection</code>, a <code>Map</code> (whose values are to be
iterated over), or an array. The collection to be iterated over must be
specified in one of the following ways:</p>
<ul>
<li>As a runtime expression specified as the value of the
<code>collection</code> attribute.</li>
<li>As a JSP bean specified by the <code>name</code> attribute.</li>
<li>As the property, specified by the <code>property</code>, of the
JSP bean specified by the <code>name</code> attribute.</li>
</ul>
<p>The collection to be iterated over MUST conform to one of the following
requirements in order for iteration to be successful:</p>
<ul>
<li>An array of Java objects or primitives.</li>
<li>An implementation of <code>java.util.Collection</code>, including
<code>ArrayList</code> and <code>Vector</code>.</li>
<li>An implementation of <code>java.util.Enumeration</code>.</li>
<li>An implementation of <code>java.util.Iterator</code>.</li>
<li>An implementation of <code>java.util.Map</code>, including
<code>HashMap</code>, <code>Hashtable</code>, and
<code>TreeMap</code>. <strong>NOTE</strong> - See below for
additional information about accessing Maps.</li>
</ul>
<p>Normally, each object exposed by the iterate tag is an element
of the underlying collection you are iterating over. However, if you
iterate over a <code>Map</code>, the exposed object is of type
<code>Map.Entry</code> that has two properties:</p>
<ul>
<li><code>key</code> - The key under which this item is stored in the
underlying Map.</li>
<li><code>value</code> - The value that corresponds to this key.</li>
</ul>
<p>So, if you wish to iterate over the values of a Hashtable, you would
implement code like the following:</p>
<code>
&lt;logic:iterate id="element" name="myhashtable"&gt;<br/>
Next element is &lt;bean:write name="element" property="value"/&gt;<br/>
&lt;/logic:iterate&gt;
</code>
<p>If the collection you are iterating over can contain <code>null</code>
values, the loop will still be performed but no page scope attribute
(named by the <code>id</code> attribute) will be created for that loop
iteration. You can use the <code>&lt;logic:present&gt;</code> and
<code>&lt;logic:notPresent&gt;</code> tags to test for this case.</p>
</info>
<attribute>
<name>collection</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>A runtime expression that evaluates to a collection (conforming to
the requirements listed above) to be iterated over.</p>
</info>
</attribute>
<attribute>
<name>id</name>
<required>true</required>
<rtexprvalue>false</rtexprvalue>
<info>
<p>The name of a page scope JSP bean that will contain the current
element of the collection on each iteration, if it is not
<code>null</code>.</p>
</info>
</attribute>
<attribute>
<name>indexId</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<info>
<p>The name of a page scope JSP bean that will contain the current
index of the collection on each iteration.</p>
</info>
</attribute>
<attribute>
<name>length</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The maximum number of entries (from the underlying collection) to be
iterated through on this page. This can be either an integer that
directly expresses the desired value, or the name of a JSP bean (in
any scope) of type <code>java.lang.Integer</code> that defines the
desired value. If not present, there will be no limit on the number
of iterations performed.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The name of the JSP bean containing the collection to be iterated
(if <code>property</code> is not specified), or the JSP bean whose
property getter returns the collection to be iterated (if
<code>property</code> is specified).</p>
</info>
</attribute>
<attribute>
<name>offset</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The zero-relative index of the starting point at which entries from
the underlying collection will be iterated through. This can be either
an integer that directly expresses the desired value, or the name of a
JSP bean (in any scope) of type <code>java.lang.Integer</code> that
defines the desired value. If not present, zero is assumed (meaning
that the collection will be iterated from the beginning.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Name of the property, of the JSP bean specified by <code>name</code>,
whose getter returns the collection to be iterated.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>type</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Fully qualified Java class name of the element to be exposed through
the JSP bean named from the <code>id</code> attribute. If not present,
no type conversions will be performed. NOTE: The actual elements of
the collection must be assignment-compatible with this class, or a
request time ClassCastException will occur.</p>
</info>
</attribute>
</tag>
<tag>
<name>lessEqual</name>
<summary>
Evaluate the nested body content of this tag if the requested
variable is greater than or equal to the specified value.
</summary>
<tagclass>org.apache.struts.taglib.logic.LessEqualTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Compares the variable specified by one of the selector attributes
against the specified constant value. The nested body content of this
tag is evaluated if the variable is <strong>less than or equal</strong>
to the value.</p>
</info>
<attribute>
<name>cookie</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the cookie whose
name is specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>header</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the header whose
name is specified by this attribute. The name match is performed
in a case insensitive manner.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the JSP bean specified by this
attribute, if <code>property</code> is not specified, or the value
of the specified property of this bean, if <code>property</code>
is specified.</p>
</info>
</attribute>
<attribute>
<name>parameter</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the first, or only, value of the
request parameter specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the property (of the bean specified
by the <code>name</code> attribute) specified by this attribute.
The property reference can be simple, nested, or indexed.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>value</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The constant value to which the variable, specified by other
attribute(s) of this tag, will be compared.</p>
</info>
</attribute>
</tag>
<tag>
<name>lessThan</name>
<summary>
Evaluate the nested body content of this tag if the requested
variable is less than the specified value.
</summary>
<tagclass>org.apache.struts.taglib.logic.LessThanTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Compares the variable specified by one of the selector attributes
against the specified constant value. The nested body content of this
tag is evaluated if the variable is <strong>less than</strong>
the value.</p>
</info>
<attribute>
<name>cookie</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the cookie whose
name is specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>header</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the header whose
name is specified by this attribute. The name match is performed
in a case insensitive manner.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the JSP bean specified by this
attribute, if <code>property</code> is not specified, or the value
of the specified property of this bean, if <code>property</code>
is specified.</p>
</info>
</attribute>
<attribute>
<name>parameter</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the first, or only, value of the
request parameter specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the property (of the bean specified
by the <code>name</code> attribute) specified by this attribute.
The property reference can be simple, nested, and/or indexed.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>value</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The constant value to which the variable, specified by other
attribute(s) of this tag, will be compared.</p>
</info>
</attribute>
</tag>
<tag>
<name>match</name>
<summary>
Evaluate the nested body content of this tag if the specified value
is an appropriate substring of the requested variable.
</summary>
<tagclass>org.apache.struts.taglib.logic.MatchTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Matches the variable specified by one of the selector attributes
(as a String) against the specified constant value. If the value is
a substring (appropriately limited by the <code>location</code>
attribute), the nested body content of this tag is evaluated.</p>
</info>
<attribute>
<name>cookie</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be matched is the value of the cookie whose
name is specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>header</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be matched is the value of the header whose
name is specified by this attribute. The name match is performed
in a case insensitive manner.</p>
</info>
</attribute>
<attribute>
<name>location</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>If not specified, a match between the variable and the value may
occur at any position within the variable string. If specified, the
match must occur at the specified location (either <code>start</code>
or <code>end</code>) of the variable string.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be matched is the JSP bean specified by this
attribute, if <code>property</code> is not specified, or the value
of the specified property of this bean, if <code>property</code>
is specified.</p>
</info>
</attribute>
<attribute>
<name>parameter</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be matched is the first, or only, value of the
request parameter specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be matched is the property (of the bean specified
by the <code>name</code> attribute) specified by this attribute.
The property reference can be simple, nested, and/or indexed.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>value</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The constant value which is checked for existence as a substring
of the specified variable.</p>
</info>
</attribute>
</tag>
<tag>
<name>messagesNotPresent</name>
<summary>
Generate the nested body content of this tag if the specified
message is not present in this request.
</summary>
<tagclass>org.apache.struts.taglib.logic.MessagesNotPresentTag</tagclass>
<bodycontent>JSP</bodycontent>
<since>Struts 1.1</since>
<info>
<p>Evaluates the nested body content of this tag if
an <code>ActionMessages</code>
object, <code>ActionErrors</code> object, a String,
or a String array is not in request scope. If
such a bean is not found, nothing will be rendered.
</p>
</info>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The parameter key to retrieve the message from request scope.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Name of the property for which messages should be
retrieved. If not specified, all messages (regardless
of property) are retrieved.
</p>
</info>
</attribute>
<attribute>
<name>message</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>By default the tag will retrieve the request scope bean it will
iterate over from the <code>Globals.ERROR_KEY</code> constant string,
but if this attribute is set to 'true' the request scope bean
will be retrieved from the <code>Globals.MESSAGE_KEY</code>
constant string. Also if this is set to 'true', any value
assigned to the name attribute will be ignored.
</p>
</info>
</attribute>
</tag>
<tag>
<name>messagesPresent</name>
<summary>
Generate the nested body content of this tag if the specified
message is present in this request.
</summary>
<tagclass>org.apache.struts.taglib.logic.MessagesPresentTag</tagclass>
<bodycontent>JSP</bodycontent>
<since>Struts 1.1</since>
<info>
<p>Evaluates the nested body content of this tag if
an <code>ActionMessages</code>
object, <code>ActionErrors</code> object, a String,
or a String array is in request scope. If
such a bean is not found, nothing will be rendered.
</p>
</info>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The parameter key to retrieve the message from request scope.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Name of the property for which messages should be
retrieved. If not specified, all messages (regardless
of property) are retrieved.
</p>
</info>
</attribute>
<attribute>
<name>message</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>By default the tag will retrieve the request scope bean it will
iterate over from the <code>Globals.ERROR_KEY</code> constant string,
but if this attribute is set to 'true' the request scope bean
will be retrieved from the <code>Globals.MESSAGE_KEY</code>
constant string. Also if this is set to 'true', any value
assigned to the name attribute will be ignored.
</p>
</info>
</attribute>
</tag>
<tag>
<name>notEmpty</name>
<summary>
Evaluate the nested body content of this tag if the requested variable is
neither <code>null</code>, nor an empty string, nor an empty java.util.Collection
(tested by the .isEmpty() method on the java.util.Collection interface).
</summary>
<tagclass>org.apache.struts.taglib.logic.NotEmptyTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>This tag evaluates its nested body content only if the specified value
is present (i.e. not <code>null</code>) and is not an empty string (i.e. a
<code>java.lang.String</code> with a length of zero).</p>
<p>
<strong>JSTL</strong>: The equivalent JSTL tag is &lt;c:if&gt; using the
<code>! empty</code> operator. For example,
<br/>
<code>
&lt;c:if test="${ ! empty sessionScope.myBean.myProperty}"&gt;
do something
&lt;/c:if&gt;
</code>
</p>
</info>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the JSP bean specified by this
attribute, if <code>property</code> is not specified, or the value
of the specified property of this bean, if <code>property</code>
is specified.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the property (of the bean specified
by the <code>name</code> attribute) specified by this attribute.
The property reference can be simple, nested, and/or indexed.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
</tag>
<tag>
<name>notEqual</name>
<summary>
Evaluate the nested body content of this tag if the requested
variable is not equal to the specified value.
</summary>
<tagclass>org.apache.struts.taglib.logic.NotEqualTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Compares the variable specified by one of the selector attributes
against the specified constant value. The nested body content of this
tag is evaluated if the variable and value are <strong>not equal</strong>.
</p>
</info>
<attribute>
<name>cookie</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the cookie whose
name is specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>header</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the value of the header whose
name is specified by this attribute. The name match is performed
in a case insensitive manner.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the JSP bean specified by this
attribute, if <code>property</code> is not specified, or the value
of the specified property of this bean, if <code>property</code>
is specified.</p>
</info>
</attribute>
<attribute>
<name>parameter</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the first, or only, value of the
request parameter specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be compared is the property (of the bean specified
by the <code>name</code> attribute) specified by this attribute.
The property reference can be simple, nested, and/or indexed.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>value</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The constant value to which the variable, specified by other
attribute(s) of this tag, will be compared.</p>
</info>
</attribute>
</tag>
<tag>
<name>notMatch</name>
<summary>
Evaluate the nested body content of this tag if the specified value
is not an appropriate substring of the requested variable.
</summary>
<tagclass>org.apache.struts.taglib.logic.NotMatchTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Matches the variable specified by one of the selector attributes
(as a String) against the specified constant value. If the value is
not a substring (appropriately limited by the <code>location</code>
attribute), the nested body content of this tag is evaluated.</p>
</info>
<attribute>
<name>cookie</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be matched is the value of the cookie whose
name is specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>header</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be matched is the value of the header whose
name is specified by this attribute. The name match is performed
in a case insensitive manner.</p>
</info>
</attribute>
<attribute>
<name>location</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>If not specified, a match between the variable and the value may
occur at any position within the variable string. If specified, the
match must occur at the specified location (either <code>start</code>
or <code>end</code>) of the variable string.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be matched is the JSP bean specified by this
attribute, if <code>property</code> is not specified, or the value
of the specified property of this bean, if <code>property</code>
is specified.</p>
</info>
</attribute>
<attribute>
<name>parameter</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be matched is the first, or only, value of the
request parameter specified by this attribute.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The variable to be matched is the property (of the bean specified
by the <code>name</code> attribute) specified by this attribute.
The property reference can be simple, nested, and/or indexed.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>value</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The constant value which is checked for existence as a substring
of the specified variable.</p>
</info>
</attribute>
</tag>
<tag>
<name>notPresent</name>
<summary>
Generate the nested body content of this tag if the specified
value is not present in this request.
</summary>
<tagclass>org.apache.struts.taglib.logic.NotPresentTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Depending on which attribute is specified, this tag checks the
current request, and evaluates the nested body content of this tag
only if the specified value <strong>is not</strong> present. Only one
of the attributes may be used in one occurrence of this tag, unless
you use the <code>property</code> attribute, in which case the
<code>name</code> attribute is also required.</p>
</info>
<attribute>
<name>cookie</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks for the existence of a cookie with the specified name.</p>
</info>
</attribute>
<attribute>
<name>header</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks for the existence of an HTTP header with the specified
name. The name match is performed in a case insensitive manner.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks for the existence of a JSP bean, in any scope, with the
specified name. If <code>property</code> is also specified, checks
for a non-null property value for the specified property.</p>
</info>
</attribute>
<attribute>
<name>parameter</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks for the existence of at least one occurrence of the
specified request parameter on this request, even if the parameter
value is a zero-length string.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks for the existence of a non-null property value, returned
by a property getter method on the JSP bean (in any scope) that is
specified by the <code>name</code> attribute. Property references
can be simple, nested, and/or indexed.</p>
</info>
</attribute>
<attribute>
<name>role</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks whether the currently authenticated user (if any) has been
associated with the specified security role.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>user</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks whether the currently authenticated user principal has the
specified name.</p>
</info>
</attribute>
</tag>
<tag>
<name>present</name>
<summary>
Generate the nested body content of this tag if the specified
value is present in this request.
</summary>
<tagclass>org.apache.struts.taglib.logic.PresentTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>
<p>Depending on which attribute is specified, this tag checks the
current request, and evaluates the nested body content of this tag
only if the specified value <strong>is</strong> present. Only one
of the attributes may be used in one occurrence of this tag, unless
you use the <code>property</code> attribute, in which case the
<code>name</code> attribute is also required.</p>
</info>
<attribute>
<name>cookie</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks for the existence of a cookie with the specified name.</p>
</info>
</attribute>
<attribute>
<name>header</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks for the existence of an HTTP header with the specified
name. The name match is performed in a case insensitive manner.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks for the existence of a JSP bean, in any scope, with the
specified name. If <code>property</code> is also specified, checks
for a non-null property value for the specified property.</p>
</info>
</attribute>
<attribute>
<name>parameter</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks for the existence of at least one occurrence of the
specified request parameter on this request, even if the parameter
value is a zero-length string.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks for the existence of a non-null property value, returned
by a property getter method on the JSP bean (in any scope) that is
specified by the <code>name</code> attribute. Property references
can be simple, nested, and/or indexed.</p>
</info>
</attribute>
<attribute>
<name>role</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks whether the currently authenticated user (if any) has been
associated with any of the specified security roles. Use a comma-delimited
list to check for multiple roles. Example:
<code>&lt;logic:present role="role1,role2,role3"&gt;
code.....
&lt;/logic:present&gt;</code></p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The bean scope within which to search for the bean named by the
<code>name</code> property, or "any scope" if not specified.</p>
</info>
</attribute>
<attribute>
<name>user</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Checks whether the currently authenticated user principal has the
specified name.</p>
</info>
</attribute>
</tag>
<tag>
<name>redirect</name>
<summary>Render an HTTP Redirect</summary>
<tagclass>org.apache.struts.taglib.logic.RedirectTag</tagclass>
<body-content>empty</body-content>
<info>
<p>Performs an <code>HttpServletResponse.sendRedirect()</code>
call to the hyperlink specified by the attributes to this
tag. URL rewriting will be applied automatically, to
maintain session state in the absence of cookies.</p>
<p>The base URL for this redirect is calculated based on
which of the following attributes you specify (you must
specify exactly one of them):</p>
<ul>
<li><em>forward</em> - Use the value of this attribute as the
name of a global <code>ActionForward</code> to be looked
up, and use the application-relative or context-relative
URI found there.</li>
<li><em>href</em> - Use the value of this attribute unchanged.
</li>
<li><em>page</em> - Use the value of this attribute as an
application-relative URI, and generate a server-relative
URI by including the context path.</li>
</ul>
<p>Normally, the redirect you specify with one of the
attributes described in the previous paragraph will be left
unchanged (other than URL rewriting if necessary). However,
there are two ways you can append one or more dynamically
defined query parameters to the hyperlink -- specify a single
parameter with the <code>paramId</code> attribute (and its
associated attributes to select the value), or specify the
<code>name</code> (and optional <code>property</code>)
attributes to select a <code>java.util.Map</code> bean that
contains one or more parameter ids and corresponding values.
</p>
<p>To specify a single parameter, use the <code>paramId</code>
attribute to define the name of the request parameter to be
submitted. To specify the corresponding value, use one of the
following approaches:</p>
<ul>
<li><em>Specify only the <code>paramName</code> attribute</em>
- The named JSP bean (optionally scoped by the value of the
<code>paramScope</code> attribute) must identify a value
that can be converted to a String.</li>
<li><em>Specify both the <code>paramName</code> and
<code>paramProperty</code> attributes</em> - The specified
property getter method will be called on the JSP bean
identified by the <code>paramName</code> (and optional
<code>paramScope</code>) attributes, in order to select
a value that can be converted to a String.</li>
</ul>
<p>If you prefer to specify a <code>java.util.Map</code> that
contains all of the request parameters to be added to the
hyperlink, use one of the following techniques:</p>
<ul>
<li><em>Specify only the <code>name</code> attribute</em> -
The named JSP bean (optionally scoped by the value of
the <code>scope</code> attribute) must identify a
<code>java.util.Map</code> containing the parameters.</li>
<li><em>Specify both <code>name</code> and
<code>property</code> attributes</em> - The specified
property getter method will be called on the bean
identified by the <code>name</code> (and optional
<code>scope</code>) attributes, in order to return the
<code>java.util.Map</code> containing the parameters.</li>
</ul>
<p>As the <code>Map</code> is processed, the keys are assumed
to be the names of query parameters to be appended to the
hyperlink. The value associated with each key must be either
a String or a String array representing the parameter value(s).
If a String array is specified, more than one value for the
same query parameter name will be created.</p>
</info>
<attribute>
<name>anchor</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Optional anchor tag ("#xxx") to be added to the generated
hyperlink. Specify this value <strong>without</strong> any
"#" character.</p>
</info>
</attribute>
<attribute>
<name>forward</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Logical name of a global <code>ActionForward</code> that
contains the actual content-relative URI of the destination
of this redirect. This URI may be dynamically
modified by the inclusion of query parameters, as described
in the tag description. You <strong>must</strong> specify
exactly one of the <code>forward</code> attribute, the
<code>href</code> attribute, the <code>linkName</code>
attribute, or the <code>page</code> attribute.</p>
</info>
</attribute>
<attribute>
<name>href</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The URL to which this redirect will transfer control.
This URL may be dynamically modified
by the inclusion of query parameters, as described in the
tag description. You <strong>must</strong> specify
exactly one of the <code>forward</code> attribute, the
<code>href</code> attribute, the <code>linkName</code>
attribute, or the <code>page</code> attribute.</p>
</info>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The name of a JSP bean that contains a <code>Map</code>
representing the query parameters (if <code>property</code>
is not specified), or a JSP bean whose property getter is
called to return a <code>Map</code> (if <code>property</code>
is specified).</p>
</info>
</attribute>
<attribute>
<name>page</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The context-relative path (beginning with a "/"
character) to which this hyperlink will transfer control
if activated. This hyperlink may be dynamically modified
by the inclusion of query parameters, as described in the
tag description. You <strong>must</strong> specify exactly
one of the <code>forward</code> attribute, the
<code>href</code> attribute, the <code>linkName</code>
attribute, or the <code>page</code> attribute.</p>
</info>
</attribute>
<attribute>
<name>paramId</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The name of the request parameter that will be dynamically
added to the generated hyperlink. The corresponding value is
defined by the <code>paramName</code> and (optional)
<code>paramProperty</code> attributes, optionally scoped by
the <code>paramScope</code> attribute</p>
</info>
</attribute>
<attribute>
<name>paramName</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The name of a JSP bean that is a String containing the
value for the request parameter named by <code>paramId</code>
(if <code>paramProperty</code> is not specified), or a JSP
bean whose property getter is called to return a String
(if <code>paramProperty</code> is specified). The JSP bean
is constrained to the bean scope specified by the
<code>paramScope</code> property, if it is specified.</p>
</info>
</attribute>
<attribute>
<name>paramProperty</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The name of a property of the bean specified by the
<code>paramName</code> attribute, whose return value must
be a String containing the value of the request parameter
(named by the <code>paramId</code> attribute) that will be
dynamically added to this hyperlink.</p>
</info>
</attribute>
<attribute>
<name>paramScope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The scope within which to search for the bean specified
by the <code>paramName</code> attribute. If not specified,
all scopes are searched.</p>
</info>
</attribute>
<attribute>
<name>property</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The name of a property of the bean specified by the
<code>name</code> attribute, whose return value must be
a <code>java.util.Map</code> containing the query parameters
to be added to the hyperlink. You <strong>must</strong>
specify the <code>name</code> attribute if you specify
this attribute.</p>
</info>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>The scope within which to search for the bean specified
by the <code>name</code> attribute. If not specified, all
scopes are searched.</p>
</info>
</attribute>
<attribute>
<name>transaction</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<info>
<p>Set to <code>true</code> if you want the current
transaction control token included in the generated
URL for this redirect.</p>
</info>
</attribute>
</tag>
</taglib>
</body>
</document>