The body is trimmed while written.

If the body is empty after being trimmed, then href itself will be written as the body, decoded into in a human-readable (but possibly ambiguous) format. If the href has a scheme of mailto:, telnet:, or tel:, the scheme is stripped and the remainder of the href is displayed.

Any attribute that has no namespace and begins with param. is added to the href as a URL parameter. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes.

The body is invoked to support nested tags, but with any output discarded.

Any attribute that has no namespace and begins with param. is added to the href as a URL parameter. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes.

After forward (or forward fall-back from redirect), relative paths might not resolve relative to the current JSP page. This will be most evident when forwarding between different directories.

To keep paths relative to the page after a forward, a <base> tag is written when the path of the current JSP page does not equal the path of the original request.

A <base> tag will affect any anchor links on a page. For this reason, this <base> tag primarily exists for when a redirect has to fall-back to a forward to a resource in another path. Properly displaying the main contents in this case is considered more important than correctly behaving anchors.

Any attribute that has no namespace and begins with param. is added as a hidden form element. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes.

Forwards to another resource. Stops processing of the containing JSP page. This has three advantages over the standard <jsp:forward> tag:

1. You may clear parameters such that only those specifically added will be passed on to the next page
2. You may have other nested tags used to select and build the set of parameters
3. You may pass argument objects instead of only String parameters (see below)

Does not forward when the response has already been committed, but also does not throw any exception; logs FINE-level notice instead.

Any attribute that has no namespace and begins with param. is added to the parameters. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes. If parameters are not cleared, nested parameters are added before request parameters.

Argument objects are passed to the forwarded page via request-scope arg Map. Any arguments to the current JSP page are not automatically passed-on to the forwarded page (this differs from parameters in this way).

Any attribute that has no namespace and begins with arg. is added as an argument. The argument name is the part of the attribute name following arg.. Because this argument becomes an element in the Map named arg in the forwarded page, the attribute name and JSP Expression Language name will match precisely.

Nested <ao:arg> tags may also be used to pass arguments.

It is an error for the same argument name to be used twice (including when set as null).

The content type of this tag is text/plain.

Any attribute that has no namespace and begins with param. is added to the src as a URL parameter. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes.

The src may be provided in one of three ways, in precedence order:

1. Direct child <ao:src> tag.
2. As the src attribute
3. The body of this tag, after trimming, is valid RFC 3986 URI or RFC 3987 IRI.

Also, when usemap is not set, the alt value is required either as an attribute or a nested <ao:alt> tag.

Any attribute that has no namespace and begins with param. is added to the src as a URL parameter. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes.

Includes another resource and then continues processing of the current JSP page. This has several advantages over the standard <jsp:include> tag:

1. You may clear parameters such that only those specifically added will be passed on to the included page
2. You may have other nested tags used to select and build the set of parameters
3. You may pass argument objects instead of only String parameters (see below)
4. You may send redirects from within the included page.
5. You may send errors from within the included page.

Any attribute that has no namespace and begins with param. is added to the parameters. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes. If parameters are not cleared, nested parameters are added before request parameters.

Argument objects are passed to the included page via request-scope arg Map. Any arguments to the current JSP page are not automatically passed-on to the included page (this differs from parameters in this way). The current JSP page arguments are restored when the include completes.

Any attribute that has no namespace and begins with arg. is added as an argument. The argument name is the part of the attribute name following arg.. Because this argument becomes an element in the Map named arg in the included page, the attribute name and JSP Expression Language name will match precisely.

Nested <ao:arg> tags may also be used to pass arguments.

It is an error for the same argument name to be used twice (including when set as null).

The value may be provided in one of three ways, in precedence order:

1. Direct child <ao:value> tag.
2. As the value attribute
3. Contents of tag body, trimmed.

For type="image", the src may be provided in one of two ways, in precedence order:

1. Direct child <ao:src> tag.
2. As the src attribute

Any attribute that has no namespace and begins with param. is added to the src as a URL parameter. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes.

Any attribute that has no namespace and begins with param. is added to the href as a URL parameter. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes.

This is expected to be used along with nested <ao:area> tags.

Any number of "arg###" attributes may be provided, where ### is the substitution parameter index, starting at zero. For example, there could be arg0="First" arg1="Second" for two arguments. They will be passed-on to the message format.

Additionally, message substitution arguments may be provided by nested <ao:messageArg> tags.

These additional arguments will first fill-in any gap in the numeric ranges provided by "arg###" attributes. Because the first argument is zero, if arg1="Second" arg2="Third", then the first nested <ao:messageArg> would be applied filling the spot of arg0.

Once all gaps are filled, these additional arguments will be added after all provided as "arg###" attritutes.

This tag must be nested inside a <ao:bundle> tag.

The content type depends on the value provided to the type attribute, and defaults to text/plain. The content is checked for well-formedness based on its type:

• css or text/css - must be well-formed CSS content. (Note: Currently only checks character values.)
• javascript, application/javascript, or text/javascript - no validation
• json or application/json - no validation
• ld_json or application/ld+json - no validation
• text or text/plain - no validation
• url or text/url - must be a valid URL
• xhtml or application/xhtml+xml - must be well-formed XHTML content. (Note: Currently only checks character values.)
• xhtml_attribute or application/xhtml+xml+attribute - must be a valid XHTML attribute.
• mysql or text/x+mysql - must be valid MySQL command "mysql" input
• psql or text/x+psql - must be valid PostgreSQL command "psql" input
• sh or text/x+sh - must be valid shell script

The content may be provided in one of three ways, in precedence order:

1. Direct child <ao:content> tag.
2. As the content attribute
3. Contents of tag body, trimmed.

In addition to the usual set of coercions expected for <c:out>, also supports writing XML nodes such as for HTML snippets.

The content type depends on the value provided to the type attribute, and defaults to text/plain. The content is checked for well-formedness based on its type:

• css or text/css - must be well-formed CSS content. (Note: Currently only checks character values.)
• javascript, application/javascript, or text/javascript - no validation
• json or application/json - no validation
• ld_json or application/ld+json - no validation
• text or text/plain - no validation
• url or text/url - must be a valid URL
• xhtml or application/xhtml+xml - must be well-formed XHTML content. (Note: Currently only checks character values.)
• xhtml_attribute or application/xhtml+xml+attribute - must be a valid XHTML attribute.
• mysql or text/x+mysql - must be valid MySQL command "mysql" input
• psql or text/x+psql - must be valid PostgreSQL command "psql" input
• sh or text/x+sh - must be valid shell script

This is compatible with <encoding:out>, with the addition of allowing nested <ao:value> and <ao:type> tags.

The body, after trimming, must contain either true, false, or be empty. If empty, the readonly attribute of the parent tag is not overridden.

Redirects the browser to another location. Stops processing of the containing JSP page.

Does not send redirect when the response has already been committed, but also does not throw any exception; logs FINE-level notice instead.

Important: Redirects inside of standard <jsp:include> tags will be silently lost. Use <ao:include> instead of <jsp:include> to support redirects inside of includes.

Any attribute that has no namespace and begins with param. is added to the href as a URL parameter. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes.

Due to browser and server URL length limitations for GET requests, it is recommended to not exceed about 2000 characters for URLs, including all parameters. See WWW FAQs: What is the maximum length of a URL?

When redirecting to a resource within the application, such as for a 303 redirect-after-post response, it is recommended to provide the "page" attribute to allow automatic fallback to forward instead of redirect. With this redirect/forward combination, users will have the benefits of redirect-after-post while the system gracefully falls back to request forwarding when the GET request length limit is exceeded.

The script should not be encoded as if in HTML/XML, it must have single "&" instead of "&amp;". The script may contain any characters valid in that language, including <, >, &, \u0000 (null), or any other values.

The script will be properly encoded for the content of this tag. Thus, you may have a script of arbitrary complexity containing arbitrary data within an XHTML onclick attribute, the tags will make sure everything is properly encoded.

The content type of this tag is equal to the type set in the type attribute.

Any attribute that has no namespace and begins with param. is added to the src as a URL parameter. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes.

For simpler scenarios, the following tags are simplier alternatives:

• <encoding:javascript>
• <encoding:json>
• <encoding:ldJson>

The body, after trimming, must contain either true, false, or be empty. If empty, the selected attribute of the parent tag is not overridden.

Does not send error when the response has already been committed, but also does not throw any exception; logs FINE-level notice instead.

Important: Errors sent inside of standard <jsp:include> tags will be silently lost. Use <ao:include> instead of <jsp:include> to support sendError inside of includes.

The body, after trimming, must contain an integer or be empty. If empty, the tabindex attribute of the parent tag is not overridden.

The value may be provided in one of three ways, in precedence order:

1. Direct child <ao:value> tag.
2. As the value attribute
3. Contents of tag body.

Before the first ? symbol, may contain characters in any language. This is more flexible than a strict URL format, these characters will be automatically encoded based on context.

After the first ?, however, the parameters must be properly URL encoded and contain only valid characters. It should not be escaped for (X)HTML, meaning that parameter separators should be "&" instead of "&amp;". The proper escaping/encoding will be performed based on the context of this tag.

In order to make relative paths predictable, relative paths are interpreted from the current JSP page.

In order to keep paths app-relative, if starts with a /, the context path will be prepended to the path.

In order to simplify things behind URL mapping schemes, the href is always written starting with '/'. This avoids any need to include any <ao:base> tags.

Depending on context, the URL will be passed through HttpServletResponse.encodeURL to add any URL-based session state. Session state will never be added to external links.

To support paths in different character sets, a Unicode to ASCII URI encoding is performed on every character that is not defined in RFC 3986: Reserved Characters. To avoid ambiguity, any dynamic parameters or anchors in the URL must have been correctly encoded by the caller.

Any attribute that has no namespace and begins with param. is added to the URL as a parameter. The parameter name is the part of the attribute name following param..

When a parameter value is null it is not added. When a parameter value is an Enum, the value is obtained via Enum.name(). If the value is an Iterable, Iterator, Enumeration, or array, then each non-null element is coerced to String as a separate parameter in iteration order. Otherwise, the value itself is coerced to String for the parameter value.

Nested <ao:param> or <ao:params> tags will add parameters after any provided as attributes.

When in a CSS context, such as nested within <ao:style>, the URL is surrounded by url("…") and fully encoded as a CSS URL.

The content type of this tag is text/url.

To establish a URL context less URL manipulation, see also <encoding:url>.

If the bean is null then nothing is displayed. This is generally for compatibility with Struts 1.X and predates JSTL and Expression Language. JSTL, Expression Language, and other tags should generally be preferred.

The method attribute provides the name of the method that will be used to get the display value. If not provided, it will default to toString. This method searches for the method of the given name with no parameters. It is an error if the method is not found.

The content type depends on the value provided to the type attribute, and defaults to text/plain. The content is checked for well-formedness based on its type:

• css or text/css - must be well-formed CSS content. (Note: Currently only checks character values.)
• javascript, application/javascript, or text/javascript - no validation
• json or application/json - no validation
• ld_json or application/ld+json - no validation
• text or text/plain - no validation
• url or text/url - must be a valid URL
• xhtml or application/xhtml+xml - must be well-formed XHTML content. (Note: Currently only checks character values.)
• xhtml_attribute or application/xhtml+xml+attribute - must be a valid XHTML attribute.
• mysql or text/x+mysql - must be valid MySQL command "mysql" input
• psql or text/x+psql - must be valid PostgreSQL command "psql" input
• sh or text/x+sh - must be valid shell script