File handling in JavaScript can be done using the
varFileObject = obj.OpenTextFile("C:\\Suraj.txt", 2, true,0);
varFileObject.write("File handling in Javascript");
varFileObject.close();
</script>
</head>
Parameter 1:
Parameter 2: I/O mode, indicates the mode of file opening. Possible values are:
Parameter 4:
The user must have write access in the path specified while creating a file. In cases where there is uncertainty, it's better to write the file onto the Temporary Folder of the system. The path for the Temp folder can be found using:
FileSystemObject object and its properties and methods. This object is part of Microsoft's Scripting Engine, and thus this is applicable only to Microsoft Windows Operating Systems.<head>
<script language=javascript>
var obj = new ActiveXObject("Scripting.FileSystemObject");
<script language=javascript>
var obj = new ActiveXObject("Scripting.FileSystemObject");
varFileObject = obj.OpenTextFile("C:\\Suraj.txt", 2, true,0);
varFileObject.write("File handling in Javascript");
varFileObject.close();
</script>
</head>
Parameter 1:
PATH - The file gets created at the path specified on the client machine. If only the file name is mentioned here, the file gets saved on the desktop of the client system.Parameter 2: I/O mode, indicates the mode of file opening. Possible values are:
- 1: Opens the file for reading.
- 2: Opens the file for writing.
- 8: Opens the file for appending.
CREATE is a boolean value indicating whether to create the file if it does not exist (true) or to issue an error message if the file does not exist (false).Parameter 4:
FORMAT is optional and indicates the file type. If not specified, the default file type is ASCII. The possible values of format are:TristateUseDefault- 2: Opens the file using the system defaultTristateTrue-1: Opens the file as UnicodeTristateFalse0: Opens the file as ASCII
FileSystemObject for file handling:MoveFile(source, destination)
MoveFolder(source, destination)
CopyFile(source, destination, overwriteFlag) //overwriteFlag= true/false
CopyFolder(source, destination, overwriteFlag) //overwriteFlag= true/false
CreateFolder(folderName)
CreateTextFile(fileName, overwriteFlag)//overwriteFlag= true/false
DeleteFile(fileName, readPermissionFlag)//readPermissionFlag= true/false
DeleteFolder(folderName, readPermissionFlag)//readPermissionFlag= true/false
DriveExists(letterDrive)
FileExists(fileName)
FolderExists(folderName)
GetSpecialFolder(folderCode) /* The given folderCode is either 0 for a
windows folder, 1 for a system folder, or 2 for a temporary folder.
A full path is returned. On a typical installation, "c:\windows"
is returned as the windows folder, "c:\windows\system" is returned
as the system folder, and "c:\windows\temp" is returned as the temporary folder. */
Points of Interest
There are a few things to note before implementingFileSystemObject. Since it is an ActiveX object, it will not be created if the security level on the client machine is high. So the website has to be added to the trusted site list so that the ActiveX object can be created.The user must have write access in the path specified while creating a file. In cases where there is uncertainty, it's better to write the file onto the Temporary Folder of the system. The path for the Temp folder can be found using:
GetSpecialFolder(2)The above topic is applicable only for IE. The below link gives an idea of how to implement file operations in Mozilla. The below code can be used to check the browser type:
if (navigator.userAgent.indexOf("Opera") >= 0)
{
alert("This example doesn't work in Opera") ;
return ;
}
if (navigator.userAgent.indexOf("MSIE") >= 0)
{
alert("This example works in IE") ;
return ;
}
if (navigator.userAgent.indexOf("Mozilla") >= 0)
{
alert("This example doesn't work in Mozilla") ;
alert("Check the following link: <a href="http://www.mozilla.org/js/js-file"+
"-object.html" title="http://www.mozilla.org/js/js-file-object" +
".html">http://www.mozilla.org/js/js-file-object.html</a>") ;
return ;
}
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