database client component (3)

[Rick Parrish]

Howdy again,

Here's the description of the third and (I hope) final part
of my on going effort to turn mozilla into an effective stand-
alone database client.

The outliner widget is a very effective and relatively
efficient mechanism for displaying "computed" data. It also
lends itself very handily to displaying tabular data straight
from a database. All that is needed by the outliner widget is
to provide an implementation of the nsIOutlinerView interface.

I've done just that for the mySQL database engine. It's a
tiny DLL (53 kilobytes for the DEBUG version). I'm also
planning an ODBC version. I'll post the code (consider it
LGPL'd) for the mySQL version as an attachment momentarily.

Here's what a sample outliner XUL file looks like:

<?xml version="1.0"?>
<?xml-stylesheet href="chrome://navigator/skin/navigator.css"
   type="text/css"?>
<!DOCTYPE window>

<window xmlns:html="http://www.w3.org/1999/xhtml";
   xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
     align="vertical"
     onload="prep();"
     onclose="mySQL.close();">

<script language="JavaScript">
var mySQL = {};

function prep()
{
   mySQL = Components.classes["@mozilla.org/mySQL/Outliner;1"].createInstance();
   mySQL = mySQL.QueryInterface(Components.interfaces.mozIDataBase);
   if ( mySQL.open("test", "", "") )
   {
     alert("Set BP now!");
     var outliner = document.getElementById('ex-outliner');
     outliner.outlinerBoxObject.view = mySQL.getView("SELECT * FROM sample");
   }
}
</script>

<outliner id="ex-outliner" flex="1">
  <outlinercol id="id" label="ID" flex="1" crop="left"/>
  <outlinercol id="name" label="Name" flex="2" crop="left"/>
  <outlinercol id="address" label="Address" flex="2" crop="left"/>
  <outlinercol id="city" label="City" flex="2" crop="left"/>
  <outlinercol id="state" label="State" flex="1" crop="left"/>
  <outlinercol id="postal" label="Postal" flex="1" crop="left"/>

  <outlinerbody flex="1"/>
</outliner>

</window>

To make this work, I had to do the following:

1. have mySQL installed and running on my system
2. create a "sample" table in the test database on mySQL like so:

mySQL> use test;
mySQL> create table sample
mySQL>   (id integer not null,
mySQL>   name varchar(24),
mySQL>   address varchar(24),
mySQL>   city varchar(16),
mySQL>   state varchar(16),
mySQL>   postal varchar(10),
mySQL>   primary key(id) );
mySQL> insert into sample values(1, "Joe Cool",
mySQL>   "101 Main Street", "Houston", "Texas", "77002");
mySQL> insert into sample values(2, "Ben Stein",
mySQL>   "101 Lincoln Lane", "Houston", "Texas", "77025");
mySQL> insert into sample values(3, "Ali Gator",
mySQL>   "101 Swamp Road", "Houston", "Texas", "77005");

3. install the above XUL file as a chrome package in mozilla.
4. copy the XPCOM component files (DLL and XPT) to the
    dist/bin/components folder and register them.
5. run mozilla from a shell prompt using the chrome switch:
    > mozilla -chrome chrome://dboutliner/content

My ultimate goal is to produce a component that will serve
all three - provide RDF datasourcing for XUL templates,
handle populating a XUL dialog, and act as a view for an
outliner widget.

The penalty for using such a component shouldn't be more
that a dozen lines of JavaScript in your XUL chrome files.

A few caveats are in order: all contract IDs, interface IDs,
and interfaces are certain to change. Example: the badly
named "mozIDataBase" interface uses |char*| instead of
|PRUnichar*| for passing strings - I'll fix that at some
point. The makefile.in file is dubious at best as I haven't
even tried this on Linux yet.

Regards,
Rick Parrish
[EMAIL PROTECTED]

(code to follow)