wiki/trunk/index.mdwn

<img id="estronlogo" src="estron2-64.png">

## About Estron

Estron (formerly known as DWI) is an experimental platform for exploring ways 
of making application development simpler.

It is still hard to write large, complex, multi-user, data-driven (SQL-backed) 
applications. It doesn't matter if your development platform is the web and 
Enterprise Java Beans, C# and .net or Mono, or whether its the Gnome/GTK or KDE 
widget set and the Linux desktop; its still just plain hard. DWI is an effort 
to change this situation. Estron currently offers a simple way of developing 
data-driven (that is, SQL-backed) Gnome applications (designed with the Glade 
GUI designer). It does this by avoiding "programming" (or at least, 
"traditional programming" in C. C#, perl, python or any other "traditional" 
language), substituting instead a configuration-file like format that defines 
how various GUI elements should be hooked up to various(such as GLib 
GObjects) or SQL fields and tables. The current primary effort with DWI is to 
provide a number of well-documented, easy-to-understand, working examples that 
show how to use Estron. These examples [componenti elettronici](http://www.accessori-elettronica.it) currently include a stand-alone 
bug-tracker-like application, examples of integrating with existing GTK 
[trading videos](http://www.video-trading.com), and an example of hooking up a Glade-designed interface to a GLib 
GObject with almost no C for  at all (assuming you have a GLib GObject 
already handy :-). WhyEstron explains the motivation for estron at length; it 
includes comparisons to other similar technologies available today.

## The estron name

*estron* is a Welsh word meaning <i>foreign</i> or <i>alien</i> and is used 
here to refer to the management of foreign or alien data formats to provide a 
simple query interface and import/export mechanism. 

## Estron in its Current Form

Estron is a fairly simple and similar to that for quickly creating data-driven 
applications, that is, graphical applications that manipulate and show info 
from a database. This environment differs from others in that it is focused on 
native GTK/Gnome support through the Glade GUI designer, and thus allows you to 
build user interfaces as elegant as you can make them in Glade.

At this point, this system has enough features to be adequate for creating 
form-editing and reporting applications. Multiple SQL database vendors are 
supported through ODBC (http://www.iodbc.org) or libdbi 
(http://libdbi.sourceforge.net) drivers. There is a simple db-driver 
infrastructure so its easy to support for additional SQL API's. The system 
supports all of the basic Gtk widgets, and an additional half-dozen Gnome I/O 
widgets, such as GnomeDateEntry. 

Estron is powered by an 'engine' (libestron0) that has some fairly generic 
procedures for mapping 'fields', such as SQL table columns or widget, 
between each other, and also between other things, such as objects, hash tables 
and etc. In a certain sense, the engine can be thought of as an 
Object-to-Relational Mapping (ORM), mapping SQL to several object, 
including Glib GObjects and QOF. This engine has been designed so that it 
becomes easy to add support for all kinds of new object systems: i.e. for the 
engine to be a generic re-mapper between not just SQL and GTK but between many 
different types of object systems and data sources/sinks.

Built on top of this engine is the estron application that parses an XML-based 
file, the "estron file", that describes the connections between glade widgets 
(or objects in general) and database tables. Currently, the only way to create 
estron files is by hand. Unfortunately, this can be a fairly long and laborious 
process itself, especially when creating something a bit more sophisticated. In 
the future, we hope to have an extension to Glade, or possibly an extension to 
a database-browsing tool that will allow you to graphically make such 
connections. (Work has begun on such a tool, written in estron itself). 
QuickList is likely to become a user interface for creating estron files once it 
migrates to alioth from Sourceforge.

The grim reality is that estron won't ever become popular without a graphical 
designer. Although fairly complex apps can be readily created using estron, it 
does have a non-trivial learning curve. When we say "can be created quickly", 
we mean "days" or "weeks", as opposed to "months" for traditional database 
application development cycles. Graphical RAD tools have a way of being 
brainlessly pleasant to use, and give the impression of an even faster 
development cycle, even though the learning curve is identical.

Note that the design of the XML format is sufficiently generic that it is not 
directly tied to Glade. It should be straightforward to adopt other ORM markups 
to inter-operate with the DWI engine. It is also envisioned that other GUI 
object systems, such as PHP, could be used with DWI, so as to create 
data-driven web pages. That is, Glade is currently the only GUI driver, but 
other drivers for other GUI's should be possible. 

## Documentation

An Estron GNOME Manual is in development to cover the creation of estron files.

The developer documentation for libestron - for developers of the estron
interpreter or applications linking against libestron directly. (Most estron users will not need
this section. The developer reference generated directly from the estron source code using
doxygen. 

## Screenshots

These screenshots show a very basic note-taking bug-tracking-like
application. The screenshots are not of DWI itself, but of a simple created with it. Actually, what is shown was created by 
Glade; you'll have to take my word that there's a database behind this.
Note that if you have good glade skills, you can create prettier 
interfaces than this. 

<img src="finder.png">
<img src="edit-rec.png">
<img src="results.png">
<img src="newentry.png">

## Tutorial

To create an estron application, you need to know SQL, and you need to be able 
to write XML files. You do not need to program in C or any other language. The 
estron interpreter will run the entire application based on the estron file. 
The testbasic.estron file describes the basic note-taking application whose 
screenshots are shown above. This example file works as a tutorial and it contains 
almost complete documentation of the file format systems.


A graphical editor, to automate the creation of these XML files, is being 
developed; its currently in the pre-pre-pre-alpha stage and will fill the gap 
in the quicklist functionality - in effect, the reports on quicklist data are 
expected to be estron .

## Support

Estron is fairly small and is able to use QOF so estron uses the QOF mailing 
list. Support should be obtained by subscribing to the QOF-devel mailing list: 
http://lists.alioth.debian.org/mailman/listinfo/qof-devel.

Archives are available at: http://lists.alioth.debian.org/pipermail/qof-devel/

Alternatively, use the ofw.Estron bug 
trackers provided by alioth.

## Source

estron source is available via Debian SVN.

svn co svn+ssh://username@svn.debian.org/svn/estron/ estron

svn co svn://svn.debian.org/svn/estron/ estron

More info about [Orthodox icons](http://www.oramaworld.com/orthodox_icons.html)

To just check out the debian source:

svn co svn://svn.debian.org/svn/estron/trunk/debian estron

----

This wiki is powered by ikiwiki. Our hosting and technical support has been kindly provided by [London Removals Company](http://www.thelondonremovals.com)
----
Eric A. Meyer has been working with the Web since late 1993. He is currently employed as a Standards Evangelist with Netscape Communications while living in Cleveland, Ohio, which is a much nicer city than you've been led to believe. A graduate of and former Webmaster for Case Western Reserve University, Eric <a href="http://www.iphonelife.co.uk">iphone blog</a> coordinated the authoring and creation of the W3C's CSS Test Suite and has recently been pushing the limits of CSS-based design as hard as he can on his site css/edge  and acting as List Chaperone of the highly active css-discuss  mailing list. Author of Eric Meyer on CSS (New Riders), Cascading <a href="http://www.qualityjubail.com">Saudi Arabia</a> Style Sheets: The Definitive Guide (O'Reilly & Associates), and CSS2.0 Programmer's Reference (Osborne/McGraw-Hill) and the fairly well-known CSS <a href="http://www.fooddietandhealth.com">healthy diet</a> Browser Compatibility Charts, Eric speaks at a variety of conferences on the subject of standards, CSS use, and Web design. He <a href="http://www.aclickahead.co.uk">SEO Company</a> is also the host of "Your Father's Oldsmobile," a weekly Big Band-era radio show heard on WRUW 91.1-FM <a href="http://www.phoenixcorporategifts.com">Promotional Products</a> in Cleveland. When not otherwise busy, Eric is usually bothering his wife <a href="http://www.propa.net">Corporate Gifts</a> Kat in some fashion. 
1	<img id="estronlogo" src="estron2-64.png">
2
3	## About Estron
4
5	Estron (formerly known as DWI) is an experimental platform for exploring ways
6	of making application development simpler.
7
8	It is still hard to write large, complex, multi-user, data-driven (SQL-backed)
9	applications. It doesn't matter if your development platform is the web and
10	Enterprise Java Beans, C# and .net or Mono, or whether its the Gnome/GTK or KDE
11	widget set and the Linux desktop; its still just plain hard. DWI is an effort
12	to change this situation. Estron currently offers a simple way of developing
13	data-driven (that is, SQL-backed) Gnome applications (designed with the Glade
14	GUI designer). It does this by avoiding "programming" (or at least,
15	"traditional programming" in C. C#, perl, python or any other "traditional"
16	language), substituting instead a configuration-file like format that defines
17	how various GUI elements should be hooked up to various(such as GLib
18	GObjects) or SQL fields and tables. The current primary effort with DWI is to
19	provide a number of well-documented, easy-to-understand, working examples that
20	show how to use Estron. These examples [componenti elettronici](http://www.accessori-elettronica.it) currently include a stand-alone
21	bug-tracker-like application, examples of integrating with existing GTK
22	[trading videos](http://www.video-trading.com), and an example of hooking up a Glade-designed interface to a GLib
23	GObject with almost no C for at all (assuming you have a GLib GObject
24	already handy :-). WhyEstron explains the motivation for estron at length; it
25	includes comparisons to other similar technologies available today.
26
27	## The estron name
28
29	estron is a Welsh word meaning <i>foreign</i> or <i>alien</i> and is used
30	here to refer to the management of foreign or alien data formats to provide a
31	simple query interface and import/export mechanism.
32
33	## Estron in its Current Form
34
35	Estron is a fairly simple and similar to that for quickly creating data-driven
36	applications, that is, graphical applications that manipulate and show info
37	from a database. This environment differs from others in that it is focused on
38	native GTK/Gnome support through the Glade GUI designer, and thus allows you to
39	build user interfaces as elegant as you can make them in Glade.
40
41	At this point, this system has enough features to be adequate for creating
42	form-editing and reporting applications. Multiple SQL database vendors are
43	supported through ODBC (http://www.iodbc.org) or libdbi
44	(http://libdbi.sourceforge.net) drivers. There is a simple db-driver
45	infrastructure so its easy to support for additional SQL API's. The system
46	supports all of the basic Gtk widgets, and an additional half-dozen Gnome I/O
47	widgets, such as GnomeDateEntry.
48
49	Estron is powered by an 'engine' (libestron0) that has some fairly generic
50	procedures for mapping 'fields', such as SQL table columns or widget,
51	between each other, and also between other things, such as objects, hash tables
52	and etc. In a certain sense, the engine can be thought of as an
53	Object-to-Relational Mapping (ORM), mapping SQL to several object,
54	including Glib GObjects and QOF. This engine has been designed so that it
55	becomes easy to add support for all kinds of new object systems: i.e. for the
56	engine to be a generic re-mapper between not just SQL and GTK but between many
57	different types of object systems and data sources/sinks.
58
59	Built on top of this engine is the estron application that parses an XML-based
60	file, the "estron file", that describes the connections between glade widgets
61	(or objects in general) and database tables. Currently, the only way to create
62	estron files is by hand. Unfortunately, this can be a fairly long and laborious
63	process itself, especially when creating something a bit more sophisticated. In
64	the future, we hope to have an extension to Glade, or possibly an extension to
65	a database-browsing tool that will allow you to graphically make such
66	connections. (Work has begun on such a tool, written in estron itself).
67	QuickList is likely to become a user interface for creating estron files once it
68	migrates to alioth from Sourceforge.
69
70	The grim reality is that estron won't ever become popular without a graphical
71	designer. Although fairly complex apps can be readily created using estron, it
72	does have a non-trivial learning curve. When we say "can be created quickly",
73	we mean "days" or "weeks", as opposed to "months" for traditional database
74	application development cycles. Graphical RAD tools have a way of being
75	brainlessly pleasant to use, and give the impression of an even faster
76	development cycle, even though the learning curve is identical.
77
78	Note that the design of the XML format is sufficiently generic that it is not
79	directly tied to Glade. It should be straightforward to adopt other ORM markups
80	to inter-operate with the DWI engine. It is also envisioned that other GUI
81	object systems, such as PHP, could be used with DWI, so as to create
82	data-driven web pages. That is, Glade is currently the only GUI driver, but
83	other drivers for other GUI's should be possible.
84
85	## Documentation
86
87	An Estron GNOME Manual is in development to cover the creation of estron files.
88
89	The developer documentation for libestron - for developers of the estron
90	interpreter or applications linking against libestron directly. (Most estron users will not need
91	this section. The developer reference generated directly from the estron source code using
92	doxygen.
93
94	## Screenshots
95
96	These screenshots show a very basic note-taking bug-tracking-like
97	application. The screenshots are not of DWI itself, but of a simple created with it. Actually, what is shown was created by
98	Glade; you'll have to take my word that there's a database behind this.
99	Note that if you have good glade skills, you can create prettier
100	interfaces than this.
101
102	<img src="finder.png">
103	<img src="edit-rec.png">
104	<img src="results.png">
105	<img src="newentry.png">
106
107	## Tutorial
108
109	To create an estron application, you need to know SQL, and you need to be able
110	to write XML files. You do not need to program in C or any other language. The
111	estron interpreter will run the entire application based on the estron file.
112	The testbasic.estron file describes the basic note-taking application whose
113	screenshots are shown above. This example file works as a tutorial and it contains
114	almost complete documentation of the file format systems.
115
116
117	A graphical editor, to automate the creation of these XML files, is being
118	developed; its currently in the pre-pre-pre-alpha stage and will fill the gap
119	in the quicklist functionality - in effect, the reports on quicklist data are
120	expected to be estron .
121
122	## Support
123
124	Estron is fairly small and is able to use QOF so estron uses the QOF mailing
125	list. Support should be obtained by subscribing to the QOF-devel mailing list:
126	http://lists.alioth.debian.org/mailman/listinfo/qof-devel.
127
128	Archives are available at: http://lists.alioth.debian.org/pipermail/qof-devel/
129
130	Alternatively, use the ofw.Estron bug
131	trackers provided by alioth.
132
133	## Source
134
135	estron source is available via Debian SVN.
136
137	svn co svn+ssh://username@svn.debian.org/svn/estron/ estron
138
139	svn co svn://svn.debian.org/svn/estron/ estron
140
141	More info about [Orthodox icons](http://www.oramaworld.com/orthodox_icons.html)
142
143	To just check out the debian source:
144
145	svn co svn://svn.debian.org/svn/estron/trunk/debian estron
146
147	----
148
149	This wiki is powered by ikiwiki. Our hosting and technical support has been kindly provided by [London Removals Company](http://www.thelondonremovals.com)
150	----
151	Eric A. Meyer has been working with the Web since late 1993. He is currently employed as a Standards Evangelist with Netscape Communications while living in Cleveland, Ohio, which is a much nicer city than you've been led to believe. A graduate of and former Webmaster for Case Western Reserve University, Eric <a href="http://www.iphonelife.co.uk">iphone blog</a> coordinated the authoring and creation of the W3C's CSS Test Suite and has recently been pushing the limits of CSS-based design as hard as he can on his site css/edge and acting as List Chaperone of the highly active css-discuss mailing list. Author of Eric Meyer on CSS (New Riders), Cascading <a href="http://www.qualityjubail.com">Saudi Arabia</a> Style Sheets: The Definitive Guide (O'Reilly & Associates), and CSS2.0 Programmer's Reference (Osborne/McGraw-Hill) and the fairly well-known CSS <a href="http://www.fooddietandhealth.com">healthy diet</a> Browser Compatibility Charts, Eric speaks at a variety of conferences on the subject of standards, CSS use, and Web design. He <a href="http://www.aclickahead.co.uk">SEO Company</a> is also the host of "Your Father's Oldsmobile," a weekly Big Band-era radio show heard on WRUW 91.1-FM <a href="http://www.phoenixcorporategifts.com">Promotional Products</a> in Cleveland. When not otherwise busy, Eric is usually bothering his wife <a href="http://www.propa.net">Corporate Gifts</a> Kat in some fashion.