creativeprogramming.it

creativeprogramming.it new blog

2009-11-24T16:52:00.001-08:00

http://www.creativeprogramming.it/blogs/wp/

Joomla SAML2 Auth Extension

2009-09-25T02:55:00.000-07:00

I'm glad to annunce the opening of my first owned open source project:

SAML2 authentication for Joomla! A Joomla extension to support saml2 based SSO systems integrating simpleSAMLphp in joomla.

For use it in production you need only to install a component ad a plugin, and configure it with a web ui.

You can download it at: http://dev.garr.it/idemauth/

Videotutorial - How to install a SAML2 SP 15 minutes : http://dev.garr.it/idemauth/SPin15mins/15mins.html

You can aslo join the open source project on Kenai (i'm open to anyone): http://kenai.com/projects/idemauth

Stefano Gargiulo.

VideoTutorial -- How to get your first java application on GoogleAppEngine (with persistence!)

2009-09-01T14:33:00.001-07:00

This video tutorial is a straightforward way to getting started with google app engine java development.

It's an "hello world" application with a java persiscence (OR/M) demo.

"terrific"!

2.0 developer life it's easy..
enjoy again!

2.0 Amazing tools: Creating facebook applications with Zembly and integrating them in external java webapps with ZCL gateway

2009-08-30T14:39:00.000-07:00

Developers 2.0 have an easy life, open source communities are revolutionating the way of writing code: incapusulation of complexity is the key, sharing knowledge is the engine!

Then how to write an amazing Facebook extension for your java web-application and get more people to your 2.0 app?
it's Simple, incapsulate Facebook Apps complexity in Zembly, then incapsulate Zembly complexity in ZCL, then use ZCL in your app!

But what's Zembly? Zembly is a wonderfull idea: an all-in-browser social development environment in wich you can create applications for social networks using a set of APIs, code-editors, and re-using and customizing community developed widgets (that's the magic: in Zembly open source is mandatory!!!)

Zembly features:

Bring your creativity, bring your skills, bring your friends

* Browser-based: Do everything in your browser. No downloads or installs.
* Social programming: Create apps socially with other users, and reuse pieces and parts that they create. You choose the level of collaboration, from keeping everything private to making your app public and open source. We call it social programming.
* Social networking: Connect with other zembly developers, watch their activity feeds, and send them messages. Be an expert, or get to know one, while working side-by-side with people in your social graph.
* Templates: Community-provided templates let you create a useful application with a click. Even after you've created your application, it remains a template that you can easily customize with its graphical customization page. When you're ready, you can choose to customize every aspect of your application with zembly's IDE-class editor.
* Cloning: Find an application or widget you like in zembly and clone it to make it your own, subject to the original author's permission of course.
* IDE-class editor: When you want absolute control, use zembly's exclusive IDE-class editor to tweak any aspect of your app. Features like full syntax highlighting, error annotations, code completion, and automatic formatting and full language support for HTML, CSS, JavaScript, FBML, and FBJS give you all the power you need to make advanced changes your application.
* Programming model: zembly makes consuming popular web APIs like Yahoo, Google, Flickr, Amazon, Twitter, YouTube, Dapper, and more trivially easy, with a single line of code. zembly's philosophy is that the web is your library.
* BYOAPI: Have your own server or API? Describe it to zembly and then call it from your app. Or, publish your API to other zembly users and let them call it from their apps. zembly can make just about any RESTful API easy callable from your app with a single line of code. You can call APIs outside of zembly from your Java or JavaFx application.
* Built-in hosting: Not only is zembly the fastest and easiest way to create your application, it's the fastest and easiest way to deploy it. Click the publish button and your app just runs. Best of all, zembly apps elastically scale on Sun's cloud infrastructure so you don't need to worry about creating or maxing our your own datacenter.

yes, you've read correct: Zembly is aslo a free hosting service for Facebook apps (and not only Facebook apps..)

Oh i'm loving my work, and i'm loving my Era: open source is the new kind of freedom!!!

But stop phyloshopying, let's get concrete:

here there are the Zembly-Facebook how-tos (videotutorials)

and here there is the ZCL (Zembly Client Libary) - Java how-to:

http://kenai.com/projects/zcl/pages/GettingStartedGuide
http://kenai.com/projects/zcl/pages/Home

then what other i can say??

Eeeenjoooy!

PostgreSQL serial vs. MySQL auto_increment vs. Oracle sequence

2009-08-21T15:04:00.000-07:00

In PostgreSQL integer counters are more advanced than the MySQL auto_increments:

Them are sequences (like in Oracle) this mean that them can be used like "shared counters in the db" (very usefull in my opinion to implement a global object id between tables and can be usefull aslo in class table inheritance implementations)

This powerfull strument is a little boring to implement in Oracle:

you need to create the sequence:


create table mytable (id number,txt varchar(255));

create sequence mytable_seq
start with 1
increment by 1
nomaxvalue;

and to associate it to the column inserts with a trigger:


create trigger mytable_seq_trigger
before insert on test
for each row
begin
select mytable_seq.nextval into :new.id from dual;
end;

or instead of the trigger you can simply hardcode sequence next value call into insert statments:


insert into mytable values(mytable_seq.nextval, 'yes but who does 
hardcoded inserts today?');

but i think the best way to do this in Oracle is the following:


create table mytable (id number default mytable_seq.nextval,
 txt varchar(255));

in this way you emulate the mysql way, that's usefull too: infact in this way if you want, you can specify the id value in an insert query or get the magic just not providing any value for the id in the insert query.

this method is also the PostgreSQL's one, infact postgre combine the simplicty and comfort of MySQL auto_increments with the power of Oracle sequences:

how to declare auto_increment in postgre:


create table mytable (id serial, name chararter varying(255));

that's all!

but "serial" is just a shortcut-keyword: this is the real auto generated sql code :


CREATE SEQUENCE inscritto_column_seq
  INCREMENT 1
  MINVALUE 1
  MAXVALUE 9223372036854775807
  START 1
  CACHE 1;
ALTER TABLE inscritto_column_seq OWNER TO rdbapp;

and


ALTER TABLE mytable ALTER COLUMN id
        SET DEFAULT nextval('mytable_column_seq'::regclass);

(i think in MySQL too happen a thing of this type, but the difference is that in PostgreSQL you can create and manage manually sequences like in Oracle, and take advantage of them power... for instance think at how easy and secure can be getting the last_insert_id of a table: select currval('ente_column_seq'::regclass); )

but attention, in Postgre you got an error when try to change an integer column to serial:


create table mytable (id integer, name chararter varying(255));


alter table mytable alter column id type serial; 
(ERROR: Type serial does not exist)

this can be an issue?

uhm.. no! that's how to alter integer to sequences in postgre:


CREATE SEQUENCE mytable_id_seq
        INCREMENT 1 MINVALUE 1 MAXVALUE 9223372036854775807 START 1 CACHE 1;
    ALTER TABLE test_table ALTER COLUMN test_column
        SET DEFAULT nextval('mytable_id_seq'::regclass);

Note: if you have data in the table, instead of

MINVALUE 1

use the value returned form this query:

select max(id) from mytable;

GWT-Ext -- How to programmatically swap themes

2009-08-19T14:24:00.000-07:00

This is the source code of the nice combobox used for live changing the css theme in the gwtext demo showcase (http://www.gwt-ext.com/demo/)


public class ThemeChanger extends ComboBox {

public ThemeChanger() {

 final Store store = new SimpleStore(new String[]{"theme", "label"}, new Object[][]{
           new Object[]{"themes/green/css/xtheme-green.css", "Green"},
           new Object[]{"themes/slate/css/xtheme-slate.css", "Slate"},
       new Object[]{"js/ext/resources/css/xtheme-gray.css", "Gray"},
       new Object[]{"xtheme-default.css", "Aero Glass"},
       new Object[]{"themes/indigo/css/xtheme-indigo.css", "Indigo"},
       new Object[]{"themes/silverCherry/css/xtheme-silverCherry.css", "Silver Cherry"}
 });

 store.load();

 setFieldLabel("Select Theme");
 setEditable(false);
 setStore(store);
 setDisplayField("label");
 setForceSelection(true);
 setTriggerAction(ComboBox.ALL);
 setValue("Green");
 setFieldLabel("Switch theme");
 addListener(new ComboBoxListenerAdapter() {
    public void onSelect(ComboBox comboBox, Record record, int index) {
       String theme = record.getAsString("theme");
            CSS.swapStyleSheet("theme", theme);
    }
 });
 setWidth(100);
}
}

don't forget to add the related css includes in the GWT.xml file:

 
js/ext/resources/css/form.css
js/ext/resources/css/ext-all.css
js/ext/resources/css/xtheme-gray.css
js/ext/resources/css/xtheme-xxx ecc...

Google Chart API - the easy way to chart it!

2009-08-18T01:43:00.000-07:00

My fall in love with google is getting concrete:

I found Google Chart API: the easy way to generate charts in a web-application (less developing time, less computational cost, less loading time)

The Google Chart API is a sort of "png-webservice" that generates for you png charts on demand (on http request)..

Is very performant, and the only system dependence to get this "chart libary" working is an internet network connection on the client browser ( is not good for intranet-only webapps)

for instance if I wanna draw into blogger my own chart:

Sample 1 - Virtual machines load

I need just to call the following url:

http://chart.apis.google.com/chart?cht=bvs&chco=4D89F9,C6D9FD&chd=t:80,50,30|50,90,60&chds=0,160&chs=100x100&chl=vm1|vm2|vm3

and embed it in as src in an html img tag.

With Google Chart API you can draw millions of bar, pie, xy, area and other types of charts a day without having a draw engine running eating cpu on your server (think at critical cpu environvents, embedded systems, ecc.) aslo your server bandwith is saved in this, because the png file transfer is beetween Google and the client browser.

Sample 2 - My Ajax Framework Utilization

Table 1 - Comparsion of Charting Solutions

	Google Chart API	Server Side Chart Library	Javascript Chart Library
Server CPU Saving	yes	no	yes
Client CPU Saving	yes	yes	no
Server Bandwith Saving	yes	no	yes
Client Bandwith Saving	no	no	yes
Server-Language Agnostic (Cross Platform)	yes	no	yes
Cross Browser Compatibilty	yes	yes	non-full
Live Ajax Charts	no	no	yes
Mouseover and OnClick on chart elements	no	no	yes

Panning and Zooming	no	no	yes

As reported in the table, if you need advanced features like mouse events on chart elements, panning, live updates etc. Google Chart API is not enough: you need a javascript chart library (i suggest dojo chart that's the more stable and complete in my opinion http://dojocampus.org/explorer/#Dojox_Charting_2D_Updating ) but pay attention if you need stability: javascript charting is a cutting-edge technology!

Obviously you can simulate live updates for fun: :D (do not try this in production!)

Sample 3 - Real Time Quotations

a little java performance highlighted quote...

2009-08-14T03:25:00.000-07:00

Why use Java instead of some other language like C or C++?

Java is a very portable language that allows for quick development of robust applications that work on a wide array of platforms without recompilation. Java has special support for networking and concurrent processing, which has been particularly improved in recent versions. Its exception handling capabilities make it possible to create very robust and stable applications, and it can provide a wealth of debugging information when a problem does occur so that its cause can be quickly identified.
OpenDS is based on Java SE 5, which provides excellent performance. Java bytecode is natively compiled at runtime, which benefits from inspecting the running code and can result in performance that exceeds that of C and C++ applications. Further, there are a number of profiling and other performance analysis tools* for Java that can help identify potential hotspots and areas of contention. Finally, Java applications can benefit from performance improvements in the JVM, which is an area that is frequently being improved.

from: https://www.opends.org/wiki/page/ProjectDefinition

*Some Java profilers are open source: try netbeans 6.7 and his magnific profiler!

DWR 3.0 And Bespin are Coming

2009-07-30T09:31:00.000-07:00

I found this interesting experiment by mozilla labs (it is a good promise: in guarantee of this the fact that in it is involved the DWR father: Joe Walker)

https://bespin.mozilla.com/

and what about DWR? DWR is an amazing open source AJAX Framework for Java, with an awesome reverse ajax support and a lot of lovely features like compleate java-to-javascript object serialization (anything, including file input to java byte stream for easy uploading a file via ajax) hibernate integration, the best anti-hajacking security system, and in the upcoming 3.0 release with a fantastic server-side dojo datastore integration (you'll forgot json files and can start to write java methods that populates dijit widgets).

Stay tuned on this blog:

http://www.butterdev.com/category/dwr/

Google App Engine - Amazing free hosting service for your java and phyton webapps

2009-07-28T10:10:00.001-07:00

Someone said you: "bla bla bla... PHP is better, PHP is faster and the proof of this is that you can't find a free hosting service for java" ?

PFIU!

now you can get free java webapplication hosting on the google's scalable and powerfull computing cloud (supporting over 5.000.000 access/day):

http://googleappengine.blogspot.com/2009/04/seriously-this-time-new-language-on-app.html

http://appengine.google.com/

:D i'm starting to love google.

P.S.

To the said people: this Google choice is the proof that PHP is good and faster for developing simple webpages but when you get large, when you grow and deal with webapplications, java is faster in developing and also in running phase.

Note: PHP is faster for simple webpages just in terms of developing time, but the runtime speed is worse than the jsp (servlet) one, this because PHP is interpreted line to line (is a scripting language) contrariwise Java is compiled in bytecode, for understanding and believing in the advantage of this you can constate that most famous and official PHP accellerators, like the Zend Optimizer (that boosts PHP speed up to 6X), works compiling PHP code into bytecode and chaching it: mumble... mumble.. this is a java servlet container emulation!

At this point the "Someone" will say to you another commonplace: "yes, but Zend Optimizer speeds up PHP 6x because is written in C, but a java servlet container stands to be slower than classic PHP.." then you can open this page http://quercus.caucho.com/ and show to your lovely friend that there is a 100% Java implementation of PHP5, six times faster then the original one!

Yes, i think i'm going to write a serious "Java vs. PHP" post...

JSON Over SOAP: Easing webservices

2009-07-27T04:31:00.000-07:00

In last years XML (SOAP) affirmed itself as the standard in the "language-agnostic" webservice scenario. But there are theoretical and pratical disavantages using only XML for webservices:

XML is too verbose = a lot of network overhead to carry a few data

XML is heavy to parse (semantically strong) = CPU overhead in the encoding and the decoding process

Wide range of libraries for parsing XML but often them are too large and invasive = implicit problems of portability, time overhead for systems analysts to avoid conflicts with system libraries etc.

Too powerfull: There is not a standard way too encode objects*, lists and arrays = time overhead for developers to implement the serializer and deserializer (x2 if client and server are written in 2 different languages)

An example? Try to write an XML webservice that returns a nested associative array from a PHP application to a java one, you'll get:

a lot of code
perplexity in deciding the format for encoding and decoding the array (and the time involved to develop the code)
computational slowness

How to improve this?

An artifact idea might be to use the simplicity of JSON over the robustness of an XML webservice to encoding complex data structures in a string (return type = string = json):

in the wsdl keep a simple string return type:

< message name="getTestArrayWS" >
< part name="Result" type="xsd:string" >

JSON is a data exchange format conceptually similar to XML (language agnostic), but much more lightweight. Libraries for JSON encoding are embedded in PHP5 and much other languages, and is very easy to find a lightweight one for any programming language, the process of encoding and decoding is very simple, lightweight and standard (the JSON syntax is similar to that of JavaScript objects, this signifies that you can nest and encode array, maps, objects, lists and wathever you want, using less syntax then XML)

With json can easily encode nested arrays and objects, let see an example:

PHP server:

function getTestArrayWS()
{
$ste = new Person ();
$ste-> name = "Stefano";
$arr=array();
$arr["left"]=$ste;
$arr["right"]=array("three" => 3);
echo json_encode($arr);
}

json_output:

"left":{ "nome":"Stefano"},"right":{"three":"3"}

PHP client example:

$wsdl= "http://localhost:8080/testService/testService.WSDL" ; $
$proxy = new SoapClient($wsdl);
$json_output = $proxy->getTestArrayWS();  
$arr = json_decode($json_output);

java client example:

Service service = // ... here I get the stub from the wsdl of the webservice .. omissis... omissis ...for info see: http://java.sun.com/j2ee/1.4/docs/tutorial/doc/JAXRPC5.html
ProxyClass myStub = (ProxyClass) service.get();
String json_output = myStub.getTestArrayWS();

JSONObject arr = (JSONObject) parser.parse(json_output);
 for (Object key : arr.keySet()) {
//... is a Map containing the tagged items from WS! 
} 


References and links: 

 WSDL: http://www.w3.org/TR/wsdl 
 PHP Soap Client: http://it.php.net/soap 
 Java JSON Library used in the example: http://code.google.com/p/json-simple/ 
 JSON Examples: http://www.json.org/example.html
  Interesting discussion: http://www.oreillynet.com/xml/blog/2007/01/json_vs_soap_a_question_worth.html

Netbeans 6.7 Released!

2009-06-30T01:09:00.000-07:00

Netbeans is really becoming "the only IDE you need", with an amazing PHP support, try it:

http://www.netbeans.org/downloads/

Don't Eclipse the Sun: Netbeans is easier to use and powerfull.

Hibernate Joined Subclass Inheritance Mapping (Annotations) - HowTo

2009-06-26T07:06:00.000-07:00

Today's tutorial is on two arguments: Implementing Class Inheritance Mapping with Hibernate and applying Hibernate Search Indexing on it.

Prefaction:

The Class Inheritance Strategy selected is Joined Sublcass and the dbms used for the demo is mysql (yes, inheritance in mysql is possible thanks to hibernate obviously! :P)

1) Database Structure:

CREATE TABLE `NetworkAsset` (
`dbId` int NOT NULL AUTO_INCREMENT PRIMARY KEY,
`inventoryNo` varchar,
`macAddress` varchar,
`vendor` varchar,
`model` varchar
)

CREATE TABLE `PresonalComputer` (
`employee` varchar,
`operativeSystem` varchar,
`ipAddress` varchar
`dbId` int NOT NULL PRIMARY KEY
CONSTRAINT `PCInheritanceLaze` FOREIGN KEY (`dbId`) REFERENCES `NetworkAsset` (`dbId`)
(Note: this way is the best way to implement a joined-subclass constraint on a DBMS that
doesn't supports native inheritance)
)

CREATE TABLE `Switch` (
`portCount` int NOT NULL,
`managmentIpAddress` varchar NOT NULL,
`LanDescription` varchar NULL,
`dbId` int NOT NULL PRIMARY KEY,
CONSTRAINT `SWInheritanceLaze` FOREIGN KEY (`dbId`) REFERENCES `NetworkAsset` (`dbId`)
)

2) Hibernate CTI Mapping POJOs (with Annotations)

Note: the used annotations import is:
import javax.persistence.*

@Entity
@Table(name="NetworkAsset"
,catalog="CreativeProgrammingDemoDB"
)
@Inheritance(strategy=InheritanceType.JOINED)
public class NetworkAsset implements java.io.Serializable {
private int dbId;
private String inventoryNo
...other filelds...

@Id
@Column(name="db_id", unique=true, nullable=false)
@GeneratedValue
public int getDbId() {
return this.dbId;
}

public void setDbId(int dbId) {
this.dbId = dbId;
}
...other getter and setters...
}

@Entity
@Table(name="PersonalComputer"
,catalog="CreativeProgrammingDemoDB"
)
public class PersonalComputer extends NetworkAsset {
//private int dbId; Note: don't add the id field in subclass POJO: it's inherited!
private String ipAddress;
private String employee;
...other filelds...

@Id
@Column(name="employee", unique=true, nullable=false)
public int getEmployee() {
return this.dbId;
}

public void setEmployee(String employee) {
this.employee = employee;
}
...other getter and setters...
}

That's all for mapping joined sublass inheritance with annotations...

more info on the classic xml way and other CTI techniques:

http://docs.jboss.org/hibernate/stable/core/reference/en/html/inheritance.html

Java Browser API

2009-06-12T04:53:00.000-07:00

I found this interesting web browser entirely written in java:

http://lobobrowser.org/

it is GPL, supports HTML 4,CSS2, JavaFX and Javascript* (with AJAX support)

http://lobobrowser.org/browser/api-info.jsp

*Javascript support is limited, for instance some dojo and extjs apps doesn't works with the browser..

Redmine - project managment and bug tracking made simple

2009-06-10T03:10:00.000-07:00

Looking for an open source project managment tool?

Redmine is an evolved an easy to use multi-project managment environment

Looking for enterprise collaborative teaming tool with activity reports?

Redmine does it, and integrates LDAP for authentication.

Looking for an integrated svn or mercurial extention more simple and powerfull than trac?

Redimine manages repository in an awesome way, for instance the following svn commit:

svn commit -m "this patch closes #245"

closes the ticket and relates the diffs to the ticket history.

Your system support team has planned to kill you at your next request?

Redmine is entireley configurable by his web interface: no system support effort is required after installation.

Installation is a "next request" and you want to live enough see redmine working?

download the cross-platform bundled installer
(provided by bitnami.org - Open Soruce. Simplified. )

Issues with subversion repository LDAP authentication?

I'm going to write an how to on this. stay tuned!

javascript is evolving!

2009-06-03T12:22:00.000-07:00

Googlers introduces the ecmascript5 (aka javascript2) changes:

http://ajaxian.com/archives/ecmascript-5-changes-to-javascript

i can't still wait for it!!

Save the forest: don't destroy() dijit.Trees!

2008-10-16T04:28:00.000-07:00

Some messages in various ajax forums ask for a solution to reload the whole content of a dojo tree with a dynamic item store.

No one has proposed a good response:

Someone said: destroy the tree and re-make it! Sure.. but what will happen to my dojo connects on the tree nodes? and the dojo tree status (opened folders ecc.)? a bloodshed! no one of my connected widgets will survive after this brutal operation..

Some other said: use a ContentPane to embed the tree and reload its href: Fantastic.. ^_^ This is the same to destroy and recreate the tree but with an extra overhead due to the contentPane.

Some other other said: Use my customized reload() function.. good.! i'm just sorry to see that non one of these solutions works..

Some infidels said: This is not possible.

I say: you can save a dijit.Tree.. don't cut it: prune it! and it'll re-grow wonderfully

This is my reload function that works:

dojo.extend(dijit.Tree, {
refresh: function(){
var root=this._getRootOrFirstNode();
while((node=this._getNextNode(root))!=null){
var parent = node.getParent();
if(parent){
parent.removeChild(node);
}
node.destroyRecursive();
}
this._itemNodeMap={};
this.store._loadFinished = false;
this.store.fetch();
this._store2model();
this._load();
var parent = root.getParent();
if(parent){
parent.removeChild(root);
}
root.destroyRecursive();
},
refresh: function(store){
var root=this._getRootOrFirstNode();
while((node=this._getNextNode(root))!=null){
var parent = node.getParent();
if(parent){
parent.removeChild(node);
}
node.destroyRecursive();
}
this._itemNodeMap={};
this.store._loadFinished = false;
this.store=store;
this._store2model();
this._load();
var parent = root.getParent();
if(parent){
parent.removeChild(root);
}
root.destroyRecursive();

}
});

that you can simply use in this way:

dijit.byId('mytree').refresh();

or

newStore=new dojo.data.ItemFileReadStore({url: myURL });
dijit.byId('mytree').refresh(newStore);

good dojing to all!
Bye.

How to lookup SNMP Textual-Conventions in Perl (Net-SNMP)

2008-08-21T08:59:00.001-07:00

For the series: Demystifing SNMP

if you need to programmatically convert a value of a varbind that is defined in the mib file with a textual-convention here you can find a perl code that works:


     use SNMP; #pay attention this isn't Net::SNMP!!

     &SNMP::addMibDirs("/yourpathtomibfiles/mibs");
     $SNMP::save_descriptions=1;
     &SNMP::initMib();
     &SNMP::loadModules('ALL');
      ...
      ...
      my $obj = $SNMP::MIB{$the_varbind_oid};
      $TextConvention_To_IntegerValue_HashTable = $obj->{enum}; 
      #now enjoy with this hash table and your integer value

For example ifAdminStatus is an INTEGER, but this integer means:
(1)->up
(2)->down

whit TextConvention_To_IntegerValue_HashTable hash table you can lookup numbers to associated string values..
but attention: you need to invert keys and values in the hash table.

here is it one example that shows how hard is to manually parse mib files:


jnxCmCfgChgEventSource OBJECT-TYPE
   SYNTAX     JnxCmCfChgSource
   MAX-ACCESS read-only
   STATUS     current
   DESCRIPTION
   "The source of the configuration event."
::= { jnxCmCfgChgEventEntry 4 }


JnxCmCfChgSource ::= TEXTUAL-CONVENTION
       STATUS       current
       DESCRIPTION  "Identifies the source of config event."
       SYNTAX       INTEGER {
                        other       (1),
                        cli         (2),
                        junoscript  (3),
                        synchronize (4),
                        snmp        (5),
                        button      (6),
                        autoinstall (7),
                        unknown     (8)
                    }

Net-SNMP rocks!

Companion js: il firebug per internet explorer

2007-12-25T11:00:00.000-08:00

Ecco un tool che funzionalmente è molto simile a Firebug: Companion JS offre una comoda console per il debbugger javascript di internet explorer molto simile a quella di firebug (Non è un debbugger vero e proprio ma solamente un interfaccia grafica verso Microsoft Script Debugger)

Download it!

IE Tab, il browser 2 in 1

2007-12-20T09:02:00.000-08:00

La vita dello sviluppatore del 2.0 a volte è dura, soprattutto quando si tratta di rendere compatibile un applicazione ajax con piu browser, ci si ritrova a rimbalzare tra IE e Firefox passando il tempo ad tra un crash e l'altro di winzozz troppo impegnato a caricare le finestre delle suddette applicazioni..

con questo strumento invece potete avere IE incluso in firefox e con un semplice click osservare come si comporta la vostra applicazione nell'altro browser:

https://addons.mozilla.org/it/firefox/addon/1419

sparklines

2007-12-20T09:00:00.000-08:00

Ecco un altro bel prodotto della mente di John Resig, autore di jQuery e ragazzo prodigio del javascript della mozilla foundation.

Un bel tocco di classe lightweight per le vostre web application che vi renderà facile come non mai mostrare dei piccoli grafici cartesiani nelle pagine html:

http://ejohn.org/projects/jspark/

provatelo! è davvero semplice e leggero.

enjoy yourself!

Offerta di Lavoro

2007-12-18T09:47:00.000-08:00

jdk s.r.l azienda leader nello sviluppo di applicazioni java offre 6 posti di lavoro a:

Programmatori Java

www.jdk.it

Location: Roma
N° posti: 6
Retribuzione: 1000 € netti al mese
Contratto: 1 anno rinnovabile
Tipo attività: sviluppo di software in team
Inizio lavori: 2 gennaio 2008
Capacità richieste: 2 mesi di esperienza con java (non necessariamente lavorativa, anche i corsi e gli esami universitari fanno testo)
Per informazioni 380.3406681

Curriculum at stefano.gargiulo@roma1.infn.it

I cv piu interessanti verrano selezionati e smistati verso:

l'Esperesso (Zona C.Colombo, Roma)
Banca di Roma (Roma)
ACI (Roma)

cerchiamo anche 1 programmatore php.

Debug 2.0

2007-12-17T04:48:00.000-08:00

Finora dal punto di vista del developer l'unico lato negativo nello sviluppare applicazioni ajax era l'assenza di strumenti di debugging che permettessero un veloce tracing dell'errore (ad esempio quando si ha a che fare con oggetti del DOM creati dinamicamente è impossibile vederne il codice sorgente con la "mostra sorgente pagina"del browser e bisogna idearsi alert e altre soluzioni ben poco eleganti affinche' ci si possa capire qualcosa in fase di debug) Ma adesso basta! Ecco a voi un ottimo strumento che vi risparmierà tante arrabiature:

Firebug è un plugin di firefox davvero strabiliante, che vi permette di monitorare gli eventi javascript, le chiamate ajax (analizzando i paramentri, i tempi di risposta ed i contenuti dei postback), inoltre vi permette di definire dei breakpoint e dei watch sulle variabili del javascript, e dulcis in fundo vi permette di esplorare il DOM e l'HTML generato dinamicamente dandovi anche la possibilita' di editarlo.. Questo diviene utile anche quando si naviga in webapplication sviluppate da terzi, ad esempio l'altra settimana dovevamo recuperare tutti i messaggi contenuti nella quarantena di sophos pure message ed inoltrarli ai relativi desitnatari, purtroppo i messaggi da inlotrare erano quasi 100 mila e l'interfaccia web permetteva di selezionarne solo 1000 per volta... sarebbe stato un po scomodo fare 100 volte la stessa query.. quindi cosa abbiamo fatto? grazie a firebug abbiamo cambiato il valore della select box che indicava il massimo numero di messaggi che sophos deve mostrare nella query :

value=1000 -> value=100000

in questo modo senza operazioni invasive siamo riusciti ad hackerare il sistema (che era carente di controlli lato server) per fargli fare cio' che volevamo.

fatene buon uso!

per internet explorer invece vi rimando a questo articolo:

http://blog.monstuff.com/archives/000291.html

movelogger

2007-12-01T15:40:00.000-08:00

Ecco un bellissimo esempio di codice javascript per registrare macro dai movimenti del mouse e dagli eventi che accadono su una pagina web:

http://pure.rednoize.com/movelogger/

Davvero molto utile per un applicazione ajax visto che può essere usato sia per monitorare l'attività svolta dagli utenti che per creare dei tutorial o delle stored procedures.

http://pure.rednoize.com/2007/10/18/record-mouse-movement-using-javascript-and-ajax/

slider in javascript

2007-12-01T13:31:00.001-08:00

Con questo primo posto andremo a vedere come realizzare in 5 minuti un' add-on davvero carina per un sito web 2.0:

la barra di regolazione analogica (slider bar).

Ecco alcune applicazioni comuni che potrete realizzare con la vostra adjustment-bar abbinata ad una tecnologia ajax:

regolare il livello di zoom di un immagine
regolare il range temporale di un grafico generato dal server
regolare il volume di un contenuto multimediale
regolare la trasparenza di una scheda o di un oggetto del DOM (alpha)

e molto altro..

Vi servirà:

1 script per il drag & drop degli oggetti DOM
1 oggetto div
un immagine che rappresenta la linea della nostra barra di regolazione
un bottone o un immagine per creare il nostro selector

ma partiamo subito con un esempio pratico:

ho un immagine e voglio creare una barra che ne regoli il livello di ingrandimento del thumbinal...

img id="imgtest" width=20 heigth=20" ...

adesso prendo un immagine di una linea che mi rappresenterà la barra di regolazione...

Controllo Zoom Immagine :

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