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5 ways to use Ajax with jQuery

Venu Thomas — Tue, 25 Aug 2009 05:35:43 +0000

The people of Nettuts publishes an interesting article on using jQuery with Ajax. Specifically the 5 ways that jQuery allows us to send asynchronous requests.

$.load()
$.get()
$.post()
$.getJSON()
$.getScript()

$. load ()

This is the feature I like most about jQuery already makes one of the most common tasks of developing with Ajax is as simple and straightforward as we shall see in this example:

$("#div_links").load("/Main_Page #jq-p-Getting-Started li");

This example brought to the documentation page on jQuery, it manages to launch a request to the URL /Main_Page (usa URL Rewrite) HTML response and take the #jq-p-Getting-Started li and inserted into #div_links
Just great, comfortable and fast.

$. get ()

This is the simple function with which we can launch the server via GET requests Ajax.

$.get("test.cgi", { name: "Venu", time: "7pm" },
  function(data){
    alert("Data Loaded: " + data);
  });

By passing 3 options, 2 of which are options (rather conditional) you can request to launch the file (1) with parameters (2) and treat the response through a callback (3rd).

$. post ()

Like the above, this feature lets you send POST requests using Ajax.

$.post("test.php", { name: "Venu", time: "7pm" },
  function(data){
    alert("Data Loaded: " + data);
  });

As easy as above.

$. getJSON ()

Although the above are able to specify the type of return, the best option is to use this method to obtain the response in JSON evaludada the callback function.

$.getJSON("test.js", { name: "Venu", time: "7pm" }, function(json){
  alert("JSON Data: " + json.users[3].name);
});

Taking into account the browser, the object will use native JSON or use a system based on eval().

$. getScript ()

Although technically not an Ajax request is a request to the server and therefore has a place in the post.

$.getScript("test.js", function(){
  alert("Script loaded and executed.");
});

With this method we can load a file asynchronously using JavaScript and the parameter (2) callback can execute Javascript code that is using the js file that we want to load (1).

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FTP connection with JAVA

Venu Thomas — Mon, 24 Aug 2009 19:29:39 +0000

Java again gives us another tool.

What is FTP?

FTP protocol that allows us to send or receive data from one point to another, be it a PC, server, or any other node that is connected to a network.

Usually when you have a web host these accounts have FTP congratulate sending files from our pc to the server that is hosting our site.

Investigating around I found a FTP client library very useful, I have tried it and going great. The library JvFTP Client provides interesting tasks, including:

Uploading / downloading files
Uploading directories recursively
Concurrent data transfer
Data transfer mode passive / active
Swing components to display directories
Components AWTpara display directories

This tool is available in jvftp and can be used in two ways, you run directly the jar, or do your own programming, including the libraries in your project.

If you want to program your own example here I leave a little guide on how you can do, let’s see …

… The first thing to do is incorporate the packages downloaded from jvftp in your project. Then you import the libraries to the class in which you make the connection:

import cz.dhl.io.*;
import cz.dhl.ftp.*;
import java.io.IOException;

Now we create the connection, the connection to prepare the data before creating access the FTP site. Let’s start with the server:

FtpConnect cn = FtpConnect.newConnect("ftp://ftp.domain.com");

ftp.domain.com value which is the server you are connecting. Each ftp account that include at least the server name, username and password. To log in using that account is something like this:

// Username
cn.setUserName("username");

// Password
cn.setPassWord("password");

Then it creates an object of type FTP, which is responsible for rendering all the information from our FTP site.

Ftp ftp1 = new Ftp();

Now the connection to the FTP site to begin processing the respective tasks

ftp1.connect(cn);

A practical example to test the connection would be to show the current directory with their files:

CoFile dir = new FtpFile(ftp1.pwd(), ftp1);

// Make a list of files that have the current directory
CoFile cfls[] = dir.listCoFiles();
if ( cfls != null )
        for (int n = 0; n < cfls.length; n++)
                    System.out.println( cfls[n].getName() + (cfls[n].isDirectory() ? "/" : ""));

Finally, there is only close the connection.

ftp1.disconnect();

Download jvftp

Happy Programming!!!

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Code in C# to create a backup of a database in SQL server and restore it

Venu Thomas — Tue, 18 Aug 2009 20:04:47 +0000

Here they left a code in C # very useful when making your applications with databases in SQL server can support the database and restore it.

Support code for a button:

private void btnBackUp_Click(object sender, EventArgs e)
{
    bool bBackUpStatus = true;

    Cursor.Current = Cursors.WaitCursor; 

     if (Directory.Exists(@"c:\SQLBackup"))
        {
            if (File.Exists(@"c:\SQLBackup\wcBackUp1.bak"))
            {
                if (MessageBox.Show(@"Do you want to replace it?", "Back", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
                {
                    File.Delete(@"c:\SQLBackup\wcBackUp1.bak");
                }
                else
                    bBackUpStatus = false;
            }
        }
        else
            Directory.CreateDirectory(@"c:\SQLBackup");

        if (bFileStatus)
        {
            //Connect to DB
            SqlConnection connect;
            string con = "Data Source = localhost; Initial Catalog=dbWiseCodes ;Integrated Security = True;";
            connect = new SqlConnection(con);
            connect.Open();
            //----------------------------------------------------------------------------------------------------

            //Execute SQL---------------
            SqlCommand command;
            command = new SqlCommand(@"backup database dbWiseCodes to disk ='c:\SQLBackup\wcBackUp1.bak' with init,stats=10", connect);
            command.ExecuteNonQuery();
            //-------------------------------------------------------------------------------------------------------------------------------

            connect.Close();

            MessageBox.Show("The support of the database was successfully performed", "Back", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
}

Code for a button to restore:


private void btnRestore_Click(object sender, EventArgs e)
{

    Cursor.Current = Cursors.WaitCursor;

    try
    {
        if (File.Exists(@"c:\SQLBackup\wcBackUp1.bak"))
        {
            if (MessageBox.Show("Are you sure you restore?", "Back", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
            {
                //Connect SQL-----------
                SqlConnection connect;
                string con = "Data Source = localhost; Initial Catalog=master ;Integrated Security = True;";
                connect = new SqlConnection(con);
                connect.Open();
                //-----------------------------------------------------------------------------------------

                //Excute SQL----------------
                SqlCommand command;
          command = new SqlCommand("use master", connect);
            command.ExecuteNonQuery();
                command = new SqlCommand(@"restore database dbWiseCodes01 from disk = 'c:\SQLBackup\wcBackUp1.bak'", connect);
                command.ExecuteNonQuery();
                //--------------------------------------------------------------------------------------------------------
                connect.Close();

                MessageBox.Show("Has been restored database", "Restoration", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }
        else
            MessageBox.Show(@"Do not make any endorsement above (or is not in the correct path)", "Restoration", MessageBoxButtons.OK, MessageBoxIcon.Information);

    }
    catch (Exception exp)
    {
        MessageBox.Show(exp.Message);
    }

}

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Print PDF with JPedal

Venu Thomas — Sun, 16 Aug 2009 16:08:43 +0000

Researching a bit about the handling of a PDF document I found a library called JPedal for manipulating PDF documents from Java.
Like other libraries I’ve seen among other iText and iReport, which are very comprehensive and allow you to do many tasks, including printing. Disadvantage that the latter is that you need to have installed Acrobat Reader and for many users this is not possible.
But even with JPedal lets you see the Acrobat Reader tools within the Java application, providing a task pane for the PDF to manipulate.

With PrinterJob.lookupPrintServices can get the services available and print them PrinterJob a concrete one.

PrintService[] psService = PrinterJob.lookupPrintServices();
PrinterJob pjPrintJob = PrinterJob.getPrinterJob();
pjPrintJob.setPrintService(psService[0]);

// Assigns the size of the paper to A4.

Paper paper = new Paper();
paper.setSize(595, 842);
paper.setImageableArea(0, 0, 595, 842);
PageFormat pf = pjPrintJob.defaultPage();
pf.setPaper(paper);

Loads the PDF to be printed. The file is called wc_PDF.pdf printed and given format.

PdfDecoder pdfD = null;
pdfD = new PdfDecoder(true);
pdfD.openPdfFile("wc_PDF.pdf");
pdfD.setPageFormat(pf);

It sends the file to print

printJob.setPageable(pdfD);
printJob.print();

And to finalize the document is closed.

pdf.closePdfFile();

Download JPedal..

The example would then complete as follows:

import java.awt.print.Paper;
import java.awt.print.PrinterJob;
import java.awt.print.PageFormat;
import javax.print.PrintService;
import org.jpedal.PdfDecoder;

public final void wc_PrintPDF() {
    PdfDecoder pdfD = null;
    try {
        PrintService[] psService = PrinterJob.lookupPrintServices();
        PrinterJob pjPrintJob = PrinterJob.getPrinterJob();
        pjPrintJob.setPrintService(psService[0]);

        Paper paper = new Paper();
        paper.setSize(595, 842);
        paper.setImageableArea(0, 0, 595, 842);
        PageFormat pf = pjPrintJob.defaultPage();
        pf.setPaper(paper);

        pdfD = new PdfDecoder(true);
        pdfD.openPdfFile("wc_PDF.pdf");
        pdfD.setPageFormat(pf);

        pjPrintJob.setPageable(pdfD);
        pjPrintJob.print();
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        pdfD.closePdfFile();
    }
}

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ASP: Online Users Counter

Venu Thomas — Mon, 10 Aug 2009 18:16:05 +0000

This popular script is found in almost all sites in ASP, used to count visitors assets (present at the time), is on our website.

The code should be used in the file Global.asa. Must not be enclosed in <% and%> must be unique and that has within it. (Well, not unique, but playing with Global.asa not recommend it).

Here’s the code that goes into the Global.asa

And to show the information which the Global.asa, or to show active users as I did in my example, they should put the following on the page displaying the data:

There are currently <%=Application("Active")%> user's on our site

Happy Programming!!!

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Javascript: Tic Tac Toe

Venu Thomas — Mon, 10 Aug 2009 15:17:33 +0000

View Demo Download Code [3.29 kb]

Playing

The computer always plays with circles ( “O”) and you with blades
( “X”). Start your. To put an X have to click on the button
the bottom panel that corresponds to the position you want to put it. You can
also hand-write it, always with capital letters (without cheating, because the
computer trusts you).

The computer will make its redondel every time you put your X .
Never make a mistake, and if you neglect (and you do not cheat), you win. If you cheat, do not
work correctly.

When the game ends, the computer shows the result and increase the counters
lower. To play another game, press the button again Game , which
Clean the panel game. To clear the counters, click the Clear button Clear.

This < head> between and </head>:

And this from <body> and </body> :

Playing

The computer always plays with circles ( "O") and you with blades ( "X"). Start your. To put an X have to click on the button the bottom panel that corresponds to the position you want to put it. You can also hand-write it, always with capital letters (without cheating, because the computer trusts you).

The computer will make its redondel every time you put your X . Never make a mistake, and if you neglect (and you do not cheat), you win. If you cheat, do not work correctly.

When the game ends, the computer shows the result and increase the counters lower. To play another game, press the button again Game , which Clean the panel game. To clear the counters, click the Clear button Clear.

Happy Programming!!!

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Multiline in JavaScript

Venu Thomas — Wed, 05 Aug 2009 19:52:41 +0000

Whenever you try to write a script in Javascript that requires a string of multiple lines get an error code that is poorly trained. That is a problem for these scripts to generate HTML content, because by having a clear line and we lose we do not see exactly what you’re painting.

$('#ID').append(
   ' \
      Welcome to WiseCodes.Com! \
    '
);

var strWelcome = 'Welcome \
to WiseCodes.Com!'

The key is used (\) to indicate the line, that mysteriously causes the browser detects that it is a single line, making the job of uniting us.
A curiosity of this language that helps us to make things easier and above all clear.

Happy Programming !!!

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The best way to load javascript

Venu Thomas — Tue, 04 Aug 2009 16:27:55 +0000

Nicholas C. Zakas has been thinking about the issue and has taken 3 points needed to be taken to improve the load javascript on our pages.

* Create two files Javascript. In the first place you need to dynamically load another javascript file and the second with the code needed for our application.
* Javascript includes the first end of the page just above < / body >
* Just below we create a second tag < script > where to call / the file / s needed.

Our HTML would be more or less like this:

loadScript ()

loadScript () function is responsible for loading the Javascript file in a dynamic and responsible for implementing the code as the second parameter to indicate when it is loaded correctly.

function loadScript(url, callback){

var script = document.createElement("script")
script.type = "text/javascript";

if (script.readyState){  //IE
script.onreadystatechange = function(){
if (script.readyState == "loaded" ||
script.readyState == "complete"){
script.onreadystatechange = null;
callback();
}
};
} else {  //Others
script.onload = function(){
callback();
};
}

script.src = url;
document.getElementsByTagName("head")[0].appendChild(script);
}

Clearly, these optimizations improve outcome, although we are talking about milliseconds (or seconds in the worst case). But it’s good to know how to improve our scripts and pulirlos well.

Happy Programming!!!

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Doodle.js, library for working with canvas

Venu Thomas — Thu, 02 Jul 2009 20:43:39 +0000

Doodle.js is a library that allows us to easily work with the element

Examples

Do not miss some of the examples available on the homepage of the library:
Spiral multicolor
Rebounds multiple

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Proposal subtitle for HTML5 video tag

Venu Thomas — Thu, 02 Jul 2009 18:44:05 +0000

In Ginger’s Thoughts I read a very interesting proposal which I believe is that in just a proposal. Although the idea is very good and it might be interesting to have this in the new HTML5. The proposal is for December 2008 and so far no developments.
The idea is to include the tag HTML5′s ability to handle subtitles:

As we can see in the above code, we would be including the text tag that would allow us to establish the lang attribute of the subtitle language and select it from your control in your browser (the preset default language of your browser) .

The tag
Only indicate the location of the subtitle file to load src indicating the language lang and type type of a subtitle that we carry.

For now …
At the moment we can make use of SRT jQuert to simulate the result with Javascript.

The idea is interesting when the films arrive officially to the Internet. Huh?

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