<ao:img>

Renders an <img> tag.

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. Contents of tag body, trimmed.

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. 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.

Tag Information

Tag Class: com.aoindustries.taglib.ImgTag
TagExtraInfo Class: None
Body Content: scriptless
Display Name: None
Dynamic Attributes: true

Attributes

Name Required Evaluation Type Description
id No Runtime Object

The id of the element. A nested <ao:id> tag will override this value.

src No Runtime String

The src for the image. The src is modified in several ways to make things much easier to work with.

A nested <ao:src> tag will override this value.

In order to make relative paths predictable, relative paths are interpreted from the current JSP page, as long as all includes have been done via <ao:include> and any forward via <ao:forward>.

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 src is always written starting with '/'. This avoids any need to include any <ao:base> tags.

URL rewriting is performed as needed via HttpServletResponse.encodeURL.

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 directly nested <ao:param> or <ao:params> tag will add parameters to the src.

absolute No Runtime boolean

When true, generates an absolute URL for the src for the image. Defaults to false.

canonical No Runtime boolean

When true, will generate a Canonical URL. Canonical URLs should be used where per-user response URL rewriting (such as information added when cookies are disabled) should be avoided. Defaults to false.

addLastModified No Runtime String

If the src represents a local resource, a parameter of "lastModified=#####" may be automatically added with the timestamp of the local resource to the nearest second. May be one of true, false, or auto. Defaults to auto.

In auto mode, last modified stamping may be disabled by the client with the X-com-aoindustries-servlet-http-LastModifiedServlet-lastModified: false header.

In auto mode, last modified stamping is not performed on Canonical URLs.

width No Runtime Object

The optional width for the image. A nested <ao:width> tag will override this value.

height No Runtime Object

The optional height for the image. A nested <ao:height> tag will override this value.

alt No Runtime Object

The alt text for the image. A nested <ao:alt> tag will override this value.

title No Runtime Object

The title text for the element. A nested <ao:title> tag will override this value.

class No Runtime Object

The CSS class for the element. A nested <ao:class> tag will override this value.

style No Runtime Object

The CSS style for the element. A nested <ao:style> tag will override this value.

usemap No Runtime String

Specifies an image as a client-side image-map.

The # prefix is optional. If not provided, the # will be automatically added.

This is expected to be used along with a <ao:map> tag.

ismap No Runtime boolean

Specifies an image as a server-side image-map.

Variables

No Variables Defined.