# <ph:placeholder> Tag

The <ph:placeholder> tag implements a placeholder, which describes the behavior for a location on a JSP page. You use the placeholder designer to define a placeholder.

Multiple placeholder tags can refer to the same placeholder. Each instance of a placeholder tag invokes its placeholder definition separately. If the placeholder definition specifies multiple queries, each placeholder tag instance can display different ads, even though each instance shares the same definition.

When WebLogic Portal receives a request for a JSP that contains an ad placeholder, the placeholder tag contacts the Ad Service, a session EJB that invokes business logic to determine which ad to display.

## Syntax

<tagName attribute="value" />

## Attributes

name

Required (String) - A string that refers to a placeholder definition.

height

Optional (int) - Specifies the height (in pixels) that the placeholder uses when generating the HTML that the browser requires to display a document. The placeholder uses this value only for content types to which display dimensions apply and only if other attributes have not already defined dimensions for a given document. If you do not specify this value and other attributes have not already been defined, the browser behavior determines the height of the document.

width

Optional (int) - Specifies the width (in pixels) that the placeholder uses when generating the HTML that the browser requires to display a document. The placeholder uses this value only for content types to which display dimensions apply and only if other attributes have not already defined dimensions for a given document. If you do not specify this value and other attributes have not already been defined, the browser behavior determines the height of the document.

## Example

This example displays the ad specified in the MainPageBanner placeholder.

    <ph:placeholder name="/placeholders/MainPageBanner.pla"/>

Related Topics

Creating Placeholders

Creating Campaigns

<ad:adTarget> Tag