♦ controlled access granted only to the authorised users;
♦ dynamic access to the database, in order to generate
ipertexts and/or graphic pages based on specific user
request.
The available data, extracted from a local GIS are:
• digital cartography (1:500 scale), representing buildings,
roads, street name and numbers;
• relational database associated to the graphic elements and
external archives related to buildings’ characteristics.
Softwares used
The present work has been carried on using different softwares
that can be divided in the following categories:
1. Software for data editing
• Modular GIS Environment (MGE) by Integraph
Corporation, software used to implement the GIS
project
• Access '97, a RDBMS, Relational Database
Management System, by Microsoft
2. Software for network data distribution
• Microsoft Peer Web services, in order to configure
the local host where all the data are loaded
• GeoMedia Web Map by Intergraph Corporation,
software suitable for maps definitions (GIS vector
elements) to be distributed by World Wide Web
• Front Page '98 by Microsoft, HTML editor useful
for the site design
Particular attention has to been paid to GeoMediaWeb Map. Set
up on a Web server in Windows NT environment, this software
is able to build (using GIS data in MGE format) vector maps in
ActiveCGM™ (Active Computer Graphics Metafile) format.
The above mentioned maps can be activated, that is the
possibility to incorporate hypertext links. These links retrieve
on the associated database all the information related to the
graphic elements. ActiveCGM files loaded in a Web site can be
displayed by a standard browser such Netscape Navigator™ o
Microsoft® Internet Explorer, using different plug-in (particular
small format applications able to improve the display browser
capability). These plug-in are available, free of charge, with
GeoMedia Web Map.
2. Methodology
The methodology for the Web site design can be summarised in
the following steps:
1. GIS editing, in order to re-organise digital cartography and
associated databases in order to publish them on the Web
itself.
This step essentially concerned the MGE project, using
the MGE bundle procedures for map editing, and Access
to edit the associated database.
Cartography
• Area editing.
• Theme creation (buildings divided by
height and use, municipal fees, etc.).
• Validation of the geometric elements and
their attributes links
Database
• Check of the duplicated records.
• Buildings characteristics ASCII tables and
geometric elements correlation (by means of a
unique ID represented by the street number).
• Editing of the database reports to publish (with an
automatic updating).
Figure 3 - Methodological steps
2. Determination of the publication vectors content using
GeoMedia Web Map. In this step all the maps displayable
by the client browser have been defined, taking particular
attention to the metric quality and the graphic aspect (line
type, colour and width). Some elements have been defines
as hot spot. The hot spot definition regards the element
animation when touched by the mouse and the automatic
database data retrieval when clicked.
3. Graphical User Interface (GUI) definition, that is the user
interface allowing a user to navigate the site (in other
words the navigation paths definition by means of bars,
buttons and menus). Being the information to be published
both graphic (ActiveCGM maps) and textual (reports
extracted from the associated database), is more convenient
to devote two different parts of the display for each
operation. This has been realised by the creation of frames
(fig. 4):
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Г«*>! ,-1 ko**,«**» *.*»* Glifi *J**BS**
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Report
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Figure 4 - Pages divided by frames
