How to read and write from/into text file using javascript?

Question

Do any one have a sample code of how to read and write from/into text file using javascript

What i tried is like created a iframe and load text file into it from iframe i read the content and using string operation make some changes, and i have no idea how to write back to text file. and also on ie browser this code is not working.

My text.txt file contain First line second Line Third Line Fourth Line

<html>

<head>
  <title></title>
</head>

<body>
<script language="JavaScript" type="text/javascript">
<!--


var srcFrame;

function loadOuter(doc) {
 srcFrame = document.getElementById("hiddenContent");
 srcFrame.src = doc;



 transferHTML();

}

function transferHTML(){
 srcContent='';
 if (srcFrame.contentDocument){
 alert("document");
  srcContent=srcFrame.contentDocument.getElementsByTagName("BODY")[0].innerHTML;
 }
 else if (srcFrame.contentWindow){
  alert("window");
  srcContent=srcFrame.contentWindow.document.body.innerHTML;
 }

srcContent.length;
alert(" before push "+srcContent);
var arrayText="Last Line";
var lines = srcContent.split('\n');
lines=lines.slice(0, -1);
lines.push(arrayText,"</pre>");
lines = lines.join('\n');
srcContent=lines;
alert(srcContent);
document.getElementById("outerDisplay").innerHTML = srcContent;
}

</script>

<INPUT TYPE="button" VALUE="Test.txt" onClick="loadOuter('Test.txt')" >

<div id="outerDisplay"></div>

<iframe  id="hiddenContent" width="200" height="200" style="position:absolute;visibility:hidden;" ></iframe>

</body>

</html>

You can't and shouldn't directly access the file system from a browser. That was a gaping security hole that was plugged in years ago. — Tony Hopkinson, Feb 23 '12 at 10:21
**Where is the JS running?** In a browser? **Where is the file?** On the user's system? On an HTTP server? **Where is the HTML document** (if there is one) **?** In the same place as the file? On a different server? — Quentin, Feb 23 '12 at 10:32

Teemu · Accepted Answer · 2012-02-23T11:25:55.610

In IE this is possible using ActiveXObject and HTA. These, however, are recommended to use local only, not in the WEB. Look at: http://msdn.microsoft.com/en-us/library/ms536471%28v=vs.85%29.aspx

More info for file operations: http://msdn.microsoft.com/en-us/library/bstcxhf7%28v=vs.84%29.aspx

Basic functions below:

ActiveXObject definition:

fso=new ActiveXObject('Scripting.FileSystemObject');

Reading file:

iStream=fso.OpenTextFile('filePath',1,false);
iStream.ReadAll();
/* or looped iStream.ReadLine() */
iStream.Close();

Writing file:

oStream=fso.OpenTextFile('filePath',2,true);
oStream.WriteLine(/*your_data*/);// This usually is looped according to your data
oStream.Close();

fso-object can also be used in regular HTM-page, but you're asked to accept use of the ActiveXObject very often.

For ie browser it is perfect solution – Kunal Vashist Feb 24 '12 at 07:45 — Kunal Vashist, Feb 24 '12 at 07:45

score 0 · Answer 2 · edited May 23 '17 at 09:59

0

If you're talking about the local file system, your options are covered in Does HTML5 allow you to interact with local client files from within a browser

edited May 23 '17 at 09:59

Community

1
1

answered Feb 23 '12 at 11:07

Wayne Cornish

635
6
19

How to read and write from/into text file using javascript?

2 Answers2