index.wml

<PAGE AUTHOR="David Schweikert <dws@ee.ethz.ch>" PAGE="about">

<H1>About Gedafe</H1>

<H2*>Gedafe 1.4.0 is released!
<A href="http://isg.ee.ethz.ch/tools/gedafe/pub/NEWS">Read more...</a></H2*>

<H2>What is Gedafe?</H2>

<p>Gedafe is a Generic, Web-based, PostgreSQL Database Front-end written in
Perl. It pulls all information it needs right from the underlying database.
No database specific configuration is required in the front-end itself.
Gedafe is nevertheless End-User-Friendly. This means that it provides a full
featured Database Application Web-interface ready to be used by normal
people.</p>

<P>The main idea behind Gedafe is to put all the application logic into the
database along with meta-information on how to present the data. This allows
to use a generic front-end which gathers that information and then builds
the user interface accordingly.</P>

<H2>Application in the Database</H2>

<P>Modern databases such as PostgreSQL allow to setup rules defining what
sort of data is permitted in each field of a table. It is even possible to
store little programs (stored procedures) which get executed whenever a
value in a table is inserted/changed/deleted. The program can then take
additional action, run elaborate tests, and in the end even refuse the
modification.</P>

<P>Implementing the application in the database is good practice, as it is
highly effective in ensuring data integrity. Whatever means are used to
access the database, data-integrity rules will be enforced. Also, writing
database applications at the database level is easier, since the built-in
programming facilities of the database are tailored to this very
purpose.</p>

<p>Such Databases Applications can be implemented in a wide variety of ways.
For Gedafe to be able to to generate a web-interface for your database it
relies on a number of conventions. Check the <A
href="doc/gedafe-sql.en.html">Database Guide</a> for details.</p>

<H2>Other Gedafe Features</H2>

<UL> 

<LI> User <EM>authentication</EM> is done only at the database-level, it is
     transparent to the requested URL (after a login you get the page you
     requested initially).  Authentication is based on cookies that expire
     server-side. </LI>

<LI> Templates allow to customize the Gedafe generated Web interface</LI>

<LI> POST is used only for data that modifies the database. Every view is
     encoded in the URL. This means that you can set <em>bookmarks</em> to
     screens inside Gedafe.</li>

<LI> <EM>Double Submit Protection</EM>. It is not possible to submit the
     same form twice. This ensures that data is only entered once even when
     Gedafe is used under non standard conditions. </LI>

<LI> Gedafe can read additional setup information from special META tables
     stored alongside the production data in the database. This allows to
     enable additional Gedafe features or to override settings which Gedafe
     derived from looking at the table structure and naming scheme.</LI>

<LI> Built-in support for external reporting modules allow to easily generate
     complex reports using external Perl modules.</LI>

<LI> Every table Gedafe displays can be downloaded with a single click in
     comma separated format ready for import into a spreadsheet.</LI>

</UL>