[+/-] : How to GBK(GB2312) and UTF-8 encoding conversion between in JavaScript

following js code show to how to convert text between Simplified Chinese GB 2312 text strings into UTF8 using JavaScript.

GB2312UTF8  = {
  Dig2Dec : function(s){
      var retV = 0;
      if(s.length == 4){
          for(var i = 0; i < 4; i ++){
              retV += eval(s.charAt(i)) * Math.pow(2, 3 - i);
          }
          return retV;
      }
      return -1;
  } ,

  Hex2Utf8 : function(s){
     var retS = "";
     var tempS = "";
     var ss = "";
     if(s.length == 16){
         tempS = "1110" + s.substring(0, 4);
         tempS += "10" +  s.substring(4, 10);
         tempS += "10" + s.substring(10,16);
         var sss = "0123456789ABCDEF";
         for(var i = 0; i < 3; i ++){
            retS += "%";
            ss = tempS.substring(i * 8, (eval(i)+1)*8);
            retS += sss.charAt(this.Dig2Dec(ss.substring(0,4)));
            retS += sss.charAt(this.Dig2Dec(ss.substring(4,8)));
         }
         return retS;
     }
     return "";
  } ,

  Dec2Dig : function(n1){
      var s = "";
      var n2 = 0;
      for(var i = 0; i < 4; i++){
         n2 = Math.pow(2,3 - i);
         if(n1 >= n2){
            s += '1';
            n1 = n1 - n2;
          }
         else
          s += '0';
      }
      return s;
  },

  Str2Hex : function(s){
      var c = "";
      var n;
      var ss = "0123456789ABCDEF";
      var digS = "";
      for(var i = 0; i < s.length; i ++){
         c = s.charAt(i);
         n = ss.indexOf(c);
         digS += this.Dec2Dig(eval(n));
      }
      return digS;
  },

  GB2312ToUTF8 : function(s1){
    var s = escape(s1);
    var sa = s.split("%");
    var retV ="";
    if(sa[0] != ""){
      retV = sa[0];
    }
    for(var i = 1; i < sa.length; i ++){
      if(sa[i].substring(0,1) == "u"){
        //alert(this.Str2Hex(sa[i].substring(1,5)));
        retV += this.Hex2Utf8(this.Str2Hex(sa[i].substring(1,5)));
  if(sa[i].length){
    retV += sa[i].substring(5);
  }
      }
      else{
     retV += unescape("%" + sa[i]);
  if(sa[i].length){
    retV += sa[i].substring(5);
  }
   }
    }
    return retV;
  },

  UTF8ToGB2312 : function(str1){
        var substr = "";
        var a = "";
        var b = "";
        var c = "";
        var i = -1;
        i = str1.indexOf("%");
        if(i==-1){
          return str1;
        }
        while(i!= -1){
    if(i<3){
                substr = substr + str1.substr(0,i-1);
                str1 = str1.substr(i+1,str1.length-i);
                a = str1.substr(0,2);
                str1 = str1.substr(2,str1.length - 2);
                if(parseInt("0x" + a) & 0x80 == 0){
                  substr = substr + String.fromCharCode(parseInt("0x" + a));
                }
                else if(parseInt("0x" + a) & 0xE0 == 0xC0){ //two byte
                        b = str1.substr(1,2);
                        str1 = str1.substr(3,str1.length - 3);
                        var widechar = (parseInt("0x" + a) & 0x1F) << 6;
                        widechar = widechar | (parseInt("0x" + b) & 0x3F);
                        substr = substr + String.fromCharCode(widechar);
                }
                else{
                        b = str1.substr(1,2);
                        str1 = str1.substr(3,str1.length - 3);
                        c = str1.substr(1,2);
                        str1 = str1.substr(3,str1.length - 3);
                        var widechar = (parseInt("0x" + a) & 0x0F) << 12;
                        widechar = widechar | ((parseInt("0x" + b) & 0x3F) << 6);
                        widechar = widechar | (parseInt("0x" + c) & 0x3F);
                        substr = substr + String.fromCharCode(widechar);
                }
     }
     else {
      substr = substr + str1.substring(0,i);
      str1= str1.substring(i);
     }
              i = str1.indexOf("%");
        }

        return substr+str1;
  }
};

test:
  GBK => UTF8:
  var utf8 = GB2312UTF8.GB2312ToUTF8("中文GB2312");

  UTF8 => GBK:
  GB2312UTF8.UTF8ToGB2312(utf8);

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[+/-] : How to access a database by ADO with JavaScript

I have not found any sample that shows database access with javaScript. Well, I created one. It is very simple since Javascript has the activeXObject that allow us to call an external object in the same way that vbscript uses CreateObject.

//**************************************
// Name: ADO With JavaScript
// Description:I have not found any sample that shows database access with javaScript. Well, I created one.
// It is very simple since Javascript has the activeXObject that allow us to call an external object
// in the same way that vbscript uses CreateObject.
// By: Marcio Coelho
//
//Assumes:You need SQL Server, a valid login, and know the name of a table and at least one column to test the sample.
//
//Side Effects:None
//This code is copyrighted and has limited warranties.
//Please see http://www.Planet-Source-Code.com/xq/ASP/txtCodeId.2804/lngWId.2/qx/vb/scripts/ShowCode.htm
//for details.
//**************************************

<SCRIPT LANGUAGE=javascript>
 var conn = new ActiveXObject("ADODB.Connection") ;
 var connectionstring = "Provider=sqloledb; Data Source=itdev; Initial Catalog=pubs; User ID=sa;Password=yourpassword"
 conn.Open(connectionstring)
 var rs = new ActiveXObject("ADODB.Recordset")
 rs.Open("SELECT gif, description, page, location FROM menu1", conn)
// Be aware that I am selecting from this table, but you need to pick your own table
 while(!rs.eof)
  {
    alert(rs(0));
    rs.movenext
  }
   
   rs.close
  conn.close 
</SCRIPT>

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[+/-] : how to determine window size in javascript

Use this snippet to determine the size of an open window. Can be used in many different situations, e.g., for setting the size of a div.

<script type="text/javascript">

if (window.innerWidth)
  theWidth=window.innerWidth;
else if (document.documentElement && document.documentElement.clientWidth)
  theWidth=document.documentElement.clientWidth;
else if (document.body)
  theWidth=document.body.clientWidth;

if (window.innerHeight)
  theHeight=window.innerHeight;
else if (document.documentElement && document.documentElement.clientHeight)
  theHeight=document.documentElement.clientHeight;
else if (document.body)
  theHeight=document.body.clientHeight;
//test
//alert(theWidth+'x'+theHeight);

</script>

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[+/-] : Check Time with a Regular Expression in javascript

copy following code to save a html file, and run it.

<html>
 <body>
  <script type="text/javascript">
  function check_time()
  {
    var elem = document.getElementById('timeStr');
    var orig_str = elem.value;
    //24 hour
    var _reg = new RegExp(/^([01][0-9]|2[0-3]):[0-5][0-9]$/);
    alert(_reg.test(orig_str));
  }
  </script>
  <input type="text" id="timeStr">
  <input type="button" value="test" onclick="check_time()" />
 </body>
</html>

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[+/-] : javascript remove attribute method

removeAttribute() Syntax, Parameters and Note

Removes the specified attribute value from the element. 
Returns true (successful) or false (failed).
    
Syntax:
    
document.getElementById("elementID").removeAttribute(param1, param2)
document.all.elementID.removeAttribute(param1, param2) // IE only

Parameters:
    param1   Required; the name of the attribute.
    param2   Optional; the type of search. 
                       1           the default for a case-sensitive search
                       any other value for a non?case-sensitive search.

removeAttribute() example code

<html>
<body>
<script language="JavaScript">
 
function function2() {
    document.getElementById("mvname").removeAttribute("readOnly",0); 
} 
</script>

<input type="text" id="mvname" readOnly="true" value="remove Attribute test" size="40"/> 

<input type="button" value="remove textbox's readOnly attribute" onclick="function2();">

</body>
</html>

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[+/-] : javascript create attribute method

createAttribute() Syntax, Parameters and Note

Creates an attribute node. 
It also works with user-defined XML elements, allowing for the creation of
custom attributes.
    
Syntax:
    
document.createAttribute(param1)

Parameters:
    param1   Required; the name of the attribute.

createAttribute() example code

<html>
<body>
<script language="JavaScript">
function function1() {
    var newAttr = document.createAttribute("readOnly");
    newAttr.nodeValue = "true"
    document.getElementById("mvname").setAttributeNode(newAttr); 
} 
</script>

<input type="text" id="mvname" value="create Attribute test" size="40"/> 
<input type="button" value="Add readOnly attribute to textbox" onclick="function1();"> 

</body>
</html>

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[+/-] : A HashMap object in Javascript like the HashMap in Java

The following Map Object code is an implementation of a HashMap in java for javascript.

function Map()
{
    // members
    this.keyArray = new Array(); // Keys
    this.valArray = new Array(); // Values
        
    // methods
    this.put = put;
    this.get = get;
    this.size = size;  
    this.clear = clear;
    this.keySet = keySet;
    this.valSet = valSet;
    this.showMe = showMe;   // returns a string with all keys and values in map.
    this.findIt = findIt;
    this.remove = remove;
}

function put( key, val )
{
    var elementIndex = this.findIt( key );
    
    if( elementIndex == (-1) )
    {
        this.keyArray.push( key );
        this.valArray.push( val );
    }
    else
    {
        this.valArray[ elementIndex ] = val;
    }
}

function get( key )
{
    var result = null;
    var elementIndex = this.findIt( key );

    if( elementIndex != (-1) )
    {   
        result = this.valArray[ elementIndex ];
    }  
    
    return result;
}

function remove( key )
{
    var result = null;
    var elementIndex = this.findIt( key );

    if( elementIndex != (-1) )
    {
        this.keyArray = this.keyArray.removeAt(elementIndex);
        this.valArray = this.valArray.removeAt(elementIndex);
    }  
    
    return ;
}

function size()
{
    return (this.keyArray.length);  
}

function clear()
{
    for( var i = 0; i < this.keyArray.length; i++ )
    {
        this.keyArray.pop(); this.valArray.pop();   
    }
}

function keySet()
{
    return (this.keyArray);
}

function valSet()
{
    return (this.valArray);   
}

function showMe()
{
    var result = "";
    
    for( var i = 0; i < this.keyArray.length; i++ )
    {
        result += "Key: " + this.keyArray[ i ] + "\tValues: " + this.valArray[ i ] + "\n";
    }
    return result;
}

function findIt( key )
{
    var result = (-1);

    for( var i = 0; i < this.keyArray.length; i++ )
    {
        if( this.keyArray[ i ] == key )
        {
            result = i;
            break;
        }
    }
    return result;
}

function removeAt( index )
{
  var part1 = this.slice( 0, index);
  var part2 = this.slice( index+1 );

  return( part1.concat( part2 ) );
}
Array.prototype.removeAt = removeAt;

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[+/-] : JavaScript remove leading and trailing whitespace

  <script type="text/javascript">
    var str = "  java script  ";    
    str = str.replace(/^\s+/g,"");//remove heading whitespace
    str = str.replace(/\s+$/g,"");//remove trailing whitespace
    alert("|"+str+"|");
  </script>

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[+/-] : How to catch TAB key press with JavaScript in Firefox,Safari,Opare & IE

The example code is tested in IE, Firefox and Opare. Probably also works in Netscape as well as others like Safari.

<html>
<head>
<script type="text/javascript">
var obj;
var TAB = 9;
function catchTAB(evt,elem)
{
  obj = elem;
  var keyCode;
  if ("which" in evt)
  {// NN4 & FF &amp; Opera
    keyCode=evt.which;
  } else if ("keyCode" in evt)
  {// Safari & IE4+
    keyCode=evt.keyCode;
  } else if ("keyCode" in window.event)
  {// IE4+
    keyCode=window.event.keyCode;
  } else if ("which" in window.event)
  {
    keyCode=evt.which;
  } else  {    alert("the browser don't support");  }

  if (keyCode == TAB)
  {
    obj.value = obj.value + "\t";
    alert("TAB was pressed");
    setTimeout("obj.focus()",1);// the focus is set back to the text input
  }
}
</script>
</head>
<body>
<input type="text" onkeydown="catchTAB(event,this);">
</body>
</html>

A wonderful article about Event Models : http://developer.apple.com/internet/webcontent/eventmodels.html...
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[+/-] : JavaScript StringBuffer like java StringBuffer object

function StringBuffer()
{
  this.buffer = [];
}

StringBuffer.prototype.append = function(string) 
{ 
  this.buffer.push(string); 
  return this; 
} 

StringBuffer.prototype.toString = function()
{ 
  return this.buffer.join(""); 
}

Usage: var s = new StringBuffer(); s.append("Hello, ").append(" World!"); alert(s.toString());...
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[+/-] : javascript clock

This script displays the current time in your browser. You can choose the 12-hours format or the 24-hours format.

<html>
<head>
<title>Javascript clock</title>
<head>
<style type="text/css">
 form,label
 {
   font-family:arial, sans-serif, helvetica, "times new roman";
   font-size:10pt; /* increase or decrease the value to change the size of the font */
 }
 h1
 {
   font-family:arial, sans-serif, helvetica, "times new roman";
 }
</style>

<script type="text/javascript">
<!-- hide the code from old browsers that do not support javascript

/*
   Original: daniusr

     You are welcomed to modify this script to your needs.
  
   This script retrieves the time from the internal system clock, 
   so it is up to you to make sure the time is accurate or correct. 
*/

 function clock()
 {
    var today = new Date();
    var hours = today.getHours();
    var minutes = today.getMinutes();
    var seconds = today.getSeconds();
    var time_holder; // holds the time

    //if the first radio button is checked display 12-hours format time
    if(timeForm.stime[0].checked)
    {
        // add "AM" or "PM" if the 12-hours format is chosen
        var ampm = ((hours >= 12) ? " PM" : " AM");    

        // convert the hour to 12-hours format
        // javascript returns midnight as 0, but since the time is in the 12-hours format
        // force javascript to return 12
        hours = ((hours == 0) ? "12" : (hours > 12) ? hours - 12 : hours); 

        // add a leading zero if less than 10
        minutes = ((minutes < 10) ? "0" + minutes : minutes); 
        seconds = ((seconds < 10) ? "0" + seconds : seconds);

        time_holder = hours + ":" + minutes + ":" + seconds + ampm;

        document.getElementById('jsClock').innerHTML =  time_holder;
    }
    if(timeForm.stime[1].checked)
    {
        // add a leading zero if less than 10
        hours = ((hours < 10) ? "0" + hours : hours);
        minutes = ((minutes < 10) ? "0" + minutes : minutes); 
        seconds = ((seconds < 10) ? "0" + seconds : seconds);

        time_holder = hours + ":" + minutes + ":" + seconds;

        document.getElementById('jsClock').innerHTML = time_holder;
    } 

    if((!timeForm.stime[0].checked) && (!timeForm.stime[1].checked))
    {     
     document.getElementById('jsClock').innerHTML = "Please select a time format.";
    }
    // keep the clock ticking
    setTimeout("clock()", 1000);
}
// end hiding -->
</script>
</head>

<body onload="javascript:clock()">

    <h1 id="jsClock" style="margin:0" align="center"></h1>

    <form name="timeForm" style="margin:0">
    time format: 
    <label for="ci"><input type="radio" name="stime" id="ci">12-hours format</label>
    <label for="mi"><input type="radio" name="stime" id="mi">24-hours format</label>
    </form>

</body>
</html>

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