Convenient development of common javascript script library _ javascript skills

Javascript can play a major role in WEB programming. It writes some common functions into javascript class libraries. Save the following code as Common. js
Class library function:
1. Trim (str) -- remove spaces on both sides of the string
2. XMLEncode (str) -- encode the string in XML format.
3. ShowLabel (str, str) -- mouse prompt function (display character, prompt character)
You can set the font, color, size, background color, and border of the displayed prompt text.
4. IsEmpty (obj) -- verify that the input box is empty
5. IsInt (objStr, sign, zero) -- verify whether it is an integer, positive integer, negative integer, and whether it includes zero
6. IsFloat (objStr, sign, zero) -- verify whether it is a floating point, Positive floating point, negative floating point, and whether it includes zero
7. IsEnLetter (objStr, size) -- verify whether the letter is 26 characters long
The source code is as follows:
/*
Name: Common. js
Function: Common javascript script Library
Including:
1. Trim (str) -- remove spaces on both sides of the string
2. XMLEncode (str) -- encode the string in XML format.
3. ShowLabel (str, str) -- mouse prompt function (display character, prompt character)
4. IsEmpty (obj) -- verify that the input box is empty
5. IsInt (objStr, sign, zero) -- verify whether it is an integer
6. IsFloat (objStr, sign, zero) -- verify whether it is a floating point number.
7. IsEnLetter (objStr, size) -- verify if it is 26 letters
*/
/*
========================================================== ======================================
String operation
Trim (string): removes spaces on both sides of the string.
========================================================== ======================================
*/
/*
========================================================== ======================================
LTrim (string): removes spaces on the left.
========================================================== ======================================
*/
Function LTrim (str)
{
Var whitespace = new String ("\ t \ n \ r ");
Var s = new String (str );
If (whitespace. indexOf (s. charAt (0 ))! =-1)
{
Var j = 0, I = s. length;
While (j <I & whitespace. indexOf (s. charAt (j ))! =-1)
{
J ++;
}
S = s. substring (j, I );
}
Return s;
}
/*
========================================================== ======================================
RTrim (string): removes spaces on the right.
========================================================== ======================================
*/
Function RTrim (str)
{
Var whitespace = new String ("\ t \ n \ r ");
Var s = new String (str );
If (whitespace. indexOf (s. charAt (s. length-1 ))! =-1)
{
Var I = s. length-1;
While (I> = 0 & whitespace. indexOf (s. charAt (I ))! =-1)
{
I --;
}
S = s. substring (0, I + 1 );
}
Return s;
}
/*
========================================================== ======================================
Trim (string): removes leading and trailing spaces.
========================================================== ======================================
*/
Function Trim (str)
{
Return RTrim (LTrim (str ));
}
/*
========================================================== ====================================
XMLEncode (string): encode the string in XML format.
========================================================== ====================================
*/
Function XMLEncode (str)
{
Str = Trim (str );
Str = str. replace ("&","&");
Str = str. replace ("<","");
Str = str. replace ("'","'");
Str = str. replace ("\"",""");
Return str;
}
/*
========================================================== ==========================================================
Verification functions
========================================================== ==========================================================
*/
Function IsEmpty (obj)
{
Obj = document. getElementsByName (obj). item (0 );
If (Trim (obj. value) = "")
{
Alert ("field cannot be blank. ");
If (obj. disabled = false & obj. readOnly = false)
{
Obj. focus ();
}
}
}
/*
IsInt (string, string, int or string) test string, + or-or empty, empty or 0)
Function: determines whether it is an integer, positive integer, negative integer, positive integer + 0, negative integer + 0
*/
Function IsInt (objStr, sign, zero)
{
Var reg;
Var bolzero;
If (Trim (objStr) = "")
{
Return false;
}
Else
{
ObjStr = objStr. toString ();
}
If (sign = null) | (Trim (sign) = ""))
{
Sign = "+ -";
}
If (zero = null) | (Trim (zero) = ""))
{
Bolzero = false;
}
Else
{
Zero = zero. toString ();
If (zero = "0 ")
{
Bolzero = true;
}
Else
{
Alert ("check whether the parameter 0 is included, can only be (null, 0 )");
}
}
Switch (sign)
{
Case "+ -":
// Integer
Reg =/(^ -? | ^ \ + ?) \ D + $ /;
Break;
Case "+ ":
If (! Bolzero)
{
// Positive integer
Reg =/^ \ +? [0-9] * [1-9] [0-9] * $ /;
}
Else
{
// Positive integer + 0
// Reg =/^ \ +? \ D + $ /;
Reg =/^ \ +? [0-9] * [0-9] [0-9] * $ /;
}
Break;
Case "-":
If (! Bolzero)
{
// Negative integer
Reg =/^-[0-9] * [1-9] [0-9] * $ /;
}
Else
{
// Negative integer + 0
// Reg =/^-\ d + $ /;
Reg =/^-[0-9] * [0-9] [0-9] * $ /;
}
Break;
Default:
Alert ("Check symbol parameters, which can only be (null, + ,-)");
Return false;
Break;
}
Var r = objStr. match (reg );
If (r = null)
{
Return false;
}
Else
{
Return true;
}
}
/*
IsFloat (string, string, int or string) test string, + or-or empty, empty or 0)
Function: determines whether it is a floating point number, Positive floating point number, negative floating point number, Positive floating point number + 0, negative floating point number + 0
*/
Function IsFloat (objStr, sign, zero)
{
Var reg;
Var bolzero;
If (Trim (objStr) = "")
{
Return false;
}
Else
{
ObjStr = objStr. toString ();
}
If (sign = null) | (Trim (sign) = ""))
{
Sign = "+ -";
}
If (zero = null) | (Trim (zero) = ""))
{
Bolzero = false;
}
Else
{
Zero = zero. toString ();
If (zero = "0 ")
{
Bolzero = true;
}
Else
{
Alert ("check whether the parameter 0 is included, can only be (null, 0 )");
}
}
Switch (sign)
{
Case "+ -":
// Floating point number
Reg =/^ ((-? | \ + ?) \ D +) (\. \ d + )? $ /;
Break;
Case "+ ":
If (! Bolzero)
{
// Positive floating point number
Reg =/^ \ +? ([0-9] + \. [0-9] * [1-9] [0-9] *) | ([0-9] * [1-9] [0-9] * \. [0-9] +) | ([0-9] * [1-9] [0-9] *) $ /;
}
Else
{
// Positive floating point number + 0
Reg =/^ \ +? \ D + (\. \ d + )? $ /;
}
Break;
Case "-":
If (! Bolzero)
{
// Negative floating point number
Reg =/^-([0-9] + \. [0-9] * [1-9] [0-9] *) | ([0-9] * [1-9] [0-9] * \. [0-9] +) | ([0-9] * [1-9] [0-9] *) $ /;
}
Else
{
// Negative floating point number + 0
Reg =/^ (-\ d + (\. \ d + )?) | (0 + (\. 0 + )?)) $ /;
}
Break;
Default:
Alert ("Check symbol parameters, which can only be (null, + ,-)");
Return false;
Break;
}
Var r = objStr. match (reg );
If (r = null)
{
Return false;
}
Else
{
Return true;
}
}
/*
IsEnLetter (string, string): test string, Case (UL, U, L or ul, u, l)
*/
Function IsEnLetter (objStr, size)
{
Var reg;
If (Trim (objStr) = "")
{
Return false;
}
Else
{
ObjStr = objStr. toString ();
}
If (size = null) | (Trim (size) = ""))
{
Size = "UL ";
}
Else
{
Size = size. toUpperCase ();
}
Switch (size)
{
Case "UL ":
// Case sensitive
Reg =/^ [A-Za-z] + $ /;
Break;
Case "U ":
// Uppercase
Reg =/^ [A-Z] + $ /;
Break;
Case "L ":
// Lower case
Reg =/^ [a-z] + $ /;
Break;
Default:
Alert ("Check case parameters, can only be (null, UL, U, L )");
Return false;
Break;
}
Var r = objStr. match (reg );
If (r = null)
{
Return false;
}
Else
{
Return true;
}
}
/*
========================================================== ==================================
Function: Tips
Author: Shen Wang
Date: 2004/04/15
========================================================== ====================================
*/
// Define variables and set default values
Var LabelFontFace = ", arial, Verdana ";
Var LabelFontColor = "#000000 ";
Var LabelFontSize = "9pt ";
Var LabelFontStyle = "Font. PLAIN ";
Var LabelBorderColor = "#000000 ";
Var LabelBackColor = "# FFFFE1 ";
// Set attributes
Function SetLabelFontFace (obj)
{
Obj = Trim (obj );
If (obj = null | obj = "")
{
Obj = ", arial, Verdana ";
}
LabelFontFace = obj;
}
Function SetLabelFontColor (obj)
{
Obj = Trim (obj );
If (obj = null | obj = "")
{
Obj = "#000000 ";
}
LabelFontColor = obj;
}
Function SetLabelFontSize (obj)
{
Obj = Trim (obj );
If (obj = null | obj = "")
{
Obj = "9pt ";
}
LabelFontSize = obj;
}
Function SetLabelFontStyle (obj)
{
Obj = Trim (obj );
If (obj = null | obj = "")
{
Obj = "Font. PLAIN ";
}
LabelFontStyle = obj;
}
Function SetLabelBorderColor (obj)
{
Obj = Trim (obj );
If (obj = null | obj = "")
{
Obj = "#000000 ";
}
LabelBorderColor = obj;
}
Function SetLabelBackColor (obj)
{
Obj = Trim (obj );
If (obj = null | obj = "")
{
Obj = "# FFFFE1 ";
}
LabelBackColor = obj;
}
// Composite text style
Function SetTextStyle (str)
{
Var strRet = "";
Var strStyle = "";
StrStyle = "font-family:" + LabelFontFace + ";";
StrStyle + = "color:" + LabelFontColor + ";";
StrStyle + = "font-size:" + LabelFontSize + ";";
Switch (LabelFontStyle. toLowerCase ())
{
Case "font. plain ":
StrStyle + = "font-weight: normal ;";
StrStyle + = "font-style: normal ;";
Break;
Case "font. bold ":
StrStyle + = "font-weight: bold ;";
StrStyle + = "font-style: normal ;";
Break;
Case "font. italic ":
StrStyle + = "font-weight: normal ;";
StrStyle + = "font-style: italic ;";
Break;
Case "font. italicbold ":
Case "font. bolditalic ":
StrStyle + = "font-weight: bold ;";
StrStyle + = "font-style: italic ;";
Break;
Default:
StrStyle + = "font-weight: bold ;";
StrStyle + = "font-style: italic ;";
Break;
}
StrRet = "";
StrRet + = "" + str + "";
StrRet + = "";
Return strRet;
}
// Synthesize Table Styles
Function SetTableStyle ()
{
Var strRet = "";
StrRet + = "border-right:" + LabelBorderColor + "1px solid ;";
StrRet + = "border-top:" + LabelBorderColor + "1px solid ;";
StrRet + = "border-left:" + LabelBorderColor + "1px solid ;";
StrRet + = "border-bottom:" + LabelBorderColor + "1px solid ;";
StrRet + = "background-color:" + LabelBackColor;
Return strRet;
}
// Display prompt
Function ShowNote (str)
{
Var strHtml;
StrHtml = "";
StrHtml + ="



";StrHtml + =" ";StrHtml + =" ";StrHtml + =" ";StrHtml + ="

"+ SetTextStyle (str) +"

";
If (document. all & document. readyState = "complete ")
{
Document. all. p_Note.innerHTML = strHtml;
Document. all. p_Note.style.pixelLeft = event. clientX + document. body. scrollLeft + 10
Document. all. p_Note.style.pixelTop = event. clientY + document. body. scrollTop + 10
Document. all. p_Note.style.visibility = "visible"
}
}
// Hide the prompt
Function HideNote ()
{
If (document. all)
{
Document. all. p_Note.style.visibility = "hidden ";
}
Else
{
If (document. layers)
{
ClearInterval (currentscroll)
Document. p_Note.visibility = "hidden ";
}
}
}
// Initialization
Function Init ()
{
Specified parameter Doc ument. write ("

");
}
Init ();
// Generate the prompt character
Function ShowLabel (text, note, bclick)
{
If (bclick! = Null)
{
Return "" + text + "";
}
Else
{
Return "" + text + "";
}
}
Test page:

The Code is as follows:

Common javascript