Bug 121352 The data set binding property cannot be retrieved in report preview layout
In report preview page, the datasource/dataset property binding lists cannot be retrieved. The dataset binding can not work correctly in layout preview because it's value cannot get from the binding list. But in the data set edit page, the binding value can be got. You can refer to the attachment.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
* See the {@link ElementDefn}class for more information on metadata, including
 * the use of the metadata definition file.
 * <p>
 * Members and classes in the meta-data system include:
 * <p>
 * <ul>
 * <li>The {@link #getDefn}method gets the element meta-data.</li>
 * <li>The {@link #getPropertyDefn}method gets the meta-data for a system- or
 * user-defined property.</li>
 * <li>The {@link #validatePropertyValue}method validates a property value
 * using the rules defined in the meta-data for the * property.</li>
 * <li>The {@link ElementDefn}class provides the meta-data for an element
 * type.</li>
 * <li>The {@link ElementPropertyDefn}class provides meta-data for a property.
 * It has two subclasses:
 * {@link org.eclipse.birt.report.model.metadata.SystemPropertyDefn}for
 * built-in properties defined in the meta-data file, and
 * {@link UserPropertyDefn}for user-defined properties.</li>
 * <li>The {@link org.eclipse.birt.report.model.metadata.MetaDataDictionary}
 * singleton class provides information to the meta-data for all elements.</li>
 * </ul>
 * 
 * <h3>Styles</h3>
 * 
 * Many elements have an associated style. Style influence the set of system-
 * defined properties, as described below. They also affect the notification
 * system as described below.
 * <p>
 * This abstract base class provides style support in the handling of property
 * values, notifications and the like. Derived classes add logic to define a