Web Dynpro DropDownByKey API - IWDDropDownByKey 

Definition

A DropDownByKey UI element provides the user with a selection list from which the user can select no more than one entry. The UI element consists of a text field, a button, and a selection list. An already selected list entry is displayed in the text field. When selecting the button, a list with all possible values is displayed. The dropdown list box UI elements do not differ from each other when displayed on the screen. However, the data binding model for the DropDownByKey UI element has a completely different concept. See Data Binding Within Web Dynpro and Data Binding of a Dropdown List Box and Radio Button Group).

Display

Use

For further information about the use of the dropdown list box using key binding, refer to the description of the Web Dynpro AbstractDropDown APIand Data Binding of a Dropdown List Box and Radio Button Group.

When using a dropdown list box, always display this UI element alongside a Label UI element to ensure accessibility.

Description of the UI Element Properties

·        size
Specifies the display size of the list. The size property can be filled with the following values and is represented by the enumeration type WDDropDownListBoxSize.

small	The UI element is displayed in a small font.
standard	A default size is displayed.

Additional properties are defined in the corresponding superior classes. Refer to:
IWDAbstractDropDownByKey, IWDAbstractDropDown, IWDUIElement, IWDViewElement.

Overview of Inherited and Additional Properties

Name	Interface	Type	Initial Value	Bindable	Value Required
enabled	IWDUIElement	boolean	true	bindable	No
readOnly	IWDAbstractDropDown	boolean	false	bindable	No
selectedKey	IWDAbstractDropDownByKey	String		bindable_mandatory	Yes
size	IWDDropDownByKey	WDDropDownListBoxSize	standard	bindable	No
state	IWDAbstractDropDown	WDState	normal	bindable	No
tooltip	IWDUIElement	String (TranslatableText)		bindable	No
visible	IWDUIElement	WDVisibility	visible	bindable	No
width	IWDAbstractDropDown	String		bindable	No

 

Events

See Web Dynpro IWDAbstractDropDownByKey API.

Data Binding

See Web Dynpro IWDAbstractDropDownByKey API.

For further information, refer to Data Binding of a Dropdown List Box and Radio Button Group. For a code example, refer to Key Binding.

Mobile Characteristics

The UI element DropDownByKey supports the development of mobile applications for pocket PCs and BlackBerry wireless handhelds (see Mobile Web Dynpro).

For BlackBerry wireless handhelds, the dropdown list box is displayed as a WML tag <select>.

However, several properties supported in the desktop browser cannot be used. These include:

Variances of the properties

Properties	Pocket PC	BlackBerry wireless handheld
enabled	ignored	ignored
size	ignored	ignored
state	ignored	ignored
tooltip	ignored	ignored
width	ignored	ignored

Methods in the Web Dynpro IWDDropDownByKey API

Method Name	Parameter	Return Value	Short Description
bindingOfSize		String	Returns the path of the context element to which the size property is bound. Returns NULL if no binding exists.
bindSize	(String path)		Binds the size property to the context node specified by a path.
getSize		WDDropDownListBoxSize	Returns the value of the size property.
setSize	(WDDropDownListBoxSize value)		Sets the value of the size property.

Additional methods described in the following APIs are available using inheritance:
IWDAbstractDropDownByKey, IWDAbstractDropDown, IWDUIElement, IWDViewElement.

For detailed documentation of all inherited methods, see the documentation for the relevant APIs.