Web Dynpro FileDownload API – IWDFileDownload (SAP Library

Web Dynpro FileDownload API – IWDFileDownload

Definition

You can use the FileDownload UI element to load files from the server to the client. The data property determines the data source in the view context. The target property determines the ID of the target window in the browser. For more information about this UI element, see the Binding section below.

Description of the UI Element Properties

· data
Determines the data source of the files to be downloaded in the context.

· target
Determines the ID of the target window in the browser, if the link is activated. Either the users can specify the ID themselves or it has the value _blank, which opens an external, unnamed window.

· type
Describes the graphical representation of the FileDownload UI element. The type property can be filled with the following values and is represented by the enumeration type WDLinkType.

function		The UI element appears in the standard design and underlined.
navigation		The UI element appears underlined and in the color used for links that the user has already visited.
reporting		The UI element appears in the standard design and not underlined.
result		The UI element appears not underlined.

Overview of Inherited and Additional Properties

Name	Interface	Type	Initial Value	bindable	Value Required
data	IWDFileDownload	Object		bindable_mandatory	No
enabled	IWDUIElement	boolean	true	bindable	No
imageAlt	IWDAbstractCaption	String (TranslatableText)		bindable	No
imageFirst	IWDAbstractCaption	boolean	true	bindable	No
imageHeight	IWDLink	String		bindable	No
imageSource	IWDAbstractCaption	String		bindable	No
imageWidth	IWDLink	String		bindable	No
size	IWDLink	WDLinkSize	standard	bindable	No
target	IWDFileDownload	String	_BLANK	bindable	No
text	IWDLink	String (TranslatableText)		bindable	No
tooltip	IWDUIElement	String (TranslatableText)		bindable	No
type	IWDFileDownload	WDLinkType	navigation	bindable	No
visible	IWDUIElement	WDVisibility	visible	bindable	No
wrapping	IWDLink	boolean	false	bindable	No

Data Binding

At design time, you add the FileDownload UI element to an appropriate view. You then define a value attribute of type binary in the context of this view, also at design time; for the source text below the value attribute is called “FileDownload”.

The data property must be bound to this value attribute of data type binary, so that the file can be downloaded as a byte array. At runtime, the binary data type can be enhanced with data to allow the passing of related information when downloading a file. Using the IWDModifiableBinaryType data type, which represents an extension of the binary data type you can access the MIME type of the file, that is, either read or set the MIME type. To do this, you must implement the following source text in the wdDoInit method of the controller implementation, with which, on the one hand, the binary data type is enhanced at runtime and on the other hand, the file extension is passed on during download:

public void wdDoInit()

{

//@@begin wdDoInit()

// The FileDownload UI element requires:

IWDAttributeInfo attInfo = wdContext.nodeRoot().getNodeInfo().getAttribute("FileDownLoad");

binaryType = (IWDModifiableBinaryType) attInfo.getModifiableSimpleType();

// in addition the FileDownload UI element needs for defined resource types

binaryType.setFileName("Snow Trees.jpg");

binaryType.setMimeType(WDWebResourceType.JPG_IMAGE);

//The FileDownload UI element needs for undefined resource types

binaryType.setFileName("Snow Trees.xcc");

binaryType.setMimeType(new WDWebResourceType("xcc", "", true));

//@@end

}

Note

Note that during the download, the MIME type of the file must be set in the controller implementation. Furthermore, you must pass on additional parameters to the setMimeType method, if the data type is not available in the Java Dictionary.

Methods in the Web Dynpro IWDFileDownload API

Method Name	Parameter	Return Value	Short Description
bindData	(String path)		Binds the value of the data property to the content element specified by the path.
bindingOfData		String	Returns the path of the content element to which the data property is bound. Returns NULL if no binding exists.
bindingOfTarget		String	Returns the path of the context element to which the target property is bound. Returns NULL if no binding exists.
bindingOfType		String	Returns the path of the context element to which the type property is bound. Returns NULL if no binding exists.
bindTarget	(String path)		Binds the target property to the context node specified by a path.
bindType	(String path)		Binds the type property to the context node specified by a path.
getData		Object	Returns the value of the data property.
getTarget		String	Returns the value of the target property.
getType		WDLinkType	Returns the value of the type property.
setData	(Object data)		Sets the value of the data property.
setTarget	(String target)		Sets the value of the target property.
setType	(WDLinkType type)		Sets the value of the type property.

Additional methods described in the following APIs are available using inheritance:

IWDLink, IWDAbstractCaption, IWDUIElement, IWDViewElement.

Note

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