The <descriptorSwitch> Element

Definition and Usage

The <descriptorSwitch> element contains a set of alternative descriptors to be associated with an object. The choice is made during presentation time.

Test rules used to choose the <descriptor> element are defined by <rule> and <compositeRule> elements; <bindRule> child elements associate these rules to child <descriptor> elements of the <descriptorSwitch> element.

The rules are evaluated in the order they are defined. The first rule evaluated as true determines the chosen <descriptor> element. If all rules are evaluated as false, a default <descriptor> element, defined by the <defaultDescriptor> element,is chosen; if the <defaultDescriptor> element is not defined no descriptor is selected and the NCL player behaves as if the element does not exist.


Element Attributes Content Parent
<descriptorSwitch> id (<defaultDescriptor>?, (<bindRule> | <descriptor>)*) <descriptorBase>


Name Value Description
id It may receive any string value that begins with a letter or an underscore and that only contains letters, digits, “.”, and “_”. The id attribute uniquely identifies the element within a document.
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