Bug 149251 Inconsistent Handling of a Non-inheritable ROM Property
For a ROM property defined to be non-inheritable, an empty string property value should be consistently handled as an empty string, not as null. For example, an oda.dataSource extension defines a data source property with canInherit=false. When a oda-data-source handle get saved in a report design, it correctly includes the tag for such property, even when an empty string value is specified. <oda-data-source extensionID="my.oda.plugin" name="my Data Source" id="24"> ... <property name="ApplicationServer"></property> </oda-data-source> However, later when using the DE API to read its property value, a null is returned. Then when the report design is subsequently saved, the property tag is lost. Expects that an empty string value of a non-inhertiable property should be preserved.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
* named style. The derived class overrides the {@link #getStyle()}method to
 * return the style for use by the generic mechanisms.
 * <p>
 * An element that can have a style is called a <em>styled element</em>. The
 * style affects the styled elements in three distinct ways.
 * <ol>
 * <li>The element can include some or all of the properties defined for the
 * style element. The element defines only those that make sense for that
 * element. These <em>style properties</em> appear as if they are properties
 * of the element itself.</li>
 * <li>The element can name a shared style from which to get properties.</li>
 * <li>If element does provide the value for a style property, and the element
 * does not explicitly reference a shared style, then the application will use a
 * <em>property search</em> to find a style implicitly associated with this
 * element. This is a search upward in the containment hierarchy to find either
 * 1) a shared style referenced by a container, or 2) an predefined style
 * associated with the slot or element. For example, a label in a Container in a
 * List's Header slot will use the predefined "list-header" style unless another
 * style is defined on the style or Container.</li>
 * </ol>
 * <p>
 * Members and classes in the style system include:
 * <p>
 * <ul>
 * <li>The {@link #getStyle()}method returns the associated style, if any, for
 * this element as a generic DesignElement.</li>
 * </ul>
 * 
 * <h3>Inheritance</h3>
 *