SEKE 2012 Proceedings - Knowledge Systems Institute

Interaction State
Set
Structure
Data Item
CD title
…CD (title, artist name, year, price,
availability, álbum cover, country,
type of music, record company)
1..N (add to the
shopping basket)
Figure 1. UID Example [6]
User Entry
Interaction State Transition
Element Selection
System Output
Option Selection
III. JAVA SERVER FACES (JSF)
Java Server Faces (JSF) is a framework for developing web
applications using the Java t echnology. It follows the design
pattern MVC (Model-View-Control) and its m ost important
differential is the separation between the business model and
the visualization [5].
The FacesServelt class is the JSF controller and every
request submitted to the system must to be sent to it. For each
HTML page instantiated, its com ponents are stored in a tree
called View ID. Theses trees, in their turn, are stored in a
FacesContext object, which m aintains all the inform ation the
framework needs in order to manage the components of a page.
Each JSF page usually contains a Java object representing
its state that is called Managed Bean. The Managed Bean stores
the values of each page field and is responsible for binding the
model to the view.
As each JSF visual component has a direct representation in
a HTML component, the fram ework supports the direct
rendering of HTM L pages from JSF components. M oreover,
the framework also supports th e implementation of renderers
that create interfaces in other languages, increasing even more
the flexibility of the application.
The JSF components relevant to this work are:
• form: represents a form for sending data through the
JSF servlet;
• panelGrid: produces a table to provide an organized
arrangement of the elements grouped in it;
• panelGroup: groups a set of JSF elements. W hen it is
converted to HTML it is mapped to a SPAN or a DIV
element;
• column: represents a column of a table;
• dataTable: shows a collection of objects organized as a
table;
• outputText: represents a simple text returned by the
system;
• outputLabel: represents a label corresponding to a field
of a user input;
• inputText: represents a field of a text entry;
• outputLink: produces a hyperlink that takes the user to
another page, or another part of the current page,
without producing an action event;
• commandLink: it also produces a hyperlink, however
it produces an action event and/or the calling of a
method of the ManagedBean object;
• commandButton: has the same functionality as the
commandLink, but it has the appearance of a button;
• selectManyCheckbox: represents a set of checkboxes
from which the user can select a subset;
• selectOneRadio: represents a set of radio buttons from
which the user can select only one.
Other components defined in the JSF HTM L Tablib (such
as outputFormat, message, messages, graficImage,
inputTextArea inputSecret, i nputHidden, selectManyMenu,
selectBooleanCheckbox, selectManyListbox, selectOneMenu,
and selectOneListbox) were not utilized here either because
they have similar functionality to the previous com ponents or
because they do not have a direct relation to UID elements.
IV. MAPPING RULES
During the definition of rules for m apping UID elements to
JSF components, our initial idea was to divide the process in
two steps: first m ap the U ID elements to abstract w idgets, as
defined in [7], and then to map abstract widgets to JSF
components. The abstract widgets that would be used in this
mapping belong to the Abstract Widget Ontology defined in
[8]. This ontology is used to specify abstract interfaces that
show the inform ation exchange between the user and system,
with no reference to technologies neither to the appearance of
navigational objects. However, we r ealized that a l ot of the
relevant information available in UIDs had been lost after
mapping UID elements to abst ract widgets. Such loss of
information compromised the autom atic mapping of U ID
elements to JSF components ma inly because a particular
abstract widget could end up being represented by different JSF
components.
We realized w e needed to define rules that m ap UID
elements directly to JSF components. These rules are presented
in Table 1. They were based on the mapping of UIDs elements
to abstract widgets, the possi ble representations of JSF
components as abstract widgets, and the relevant information
available in UIDs.
TABLE I.
text
UID Elements
data item (system
output)
Structure (system
output)
MAPPING FROM UIDS ELEMENTS TO JSF COMPONENTS
JSF Components
outputText;
if the data item is the source of any
transition, it is m apped to a
commandLink;
otherwise, it is mapped to an
outputText;
if the structure is not the source of any
transition and does not contain
elements, it is mapped to an outputText;
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