javascript - atob not working in IE

Question

I am trying to use atob for converting base64 encoded data to string. I found its working fine in Mozilla and Chrome, but it is not working in IE. Please tell me any substitue for this, or how to make this work in IE

Answer 1

Go to this link and include js present there:

http://code.google.com/p/stringencoders/source/browse/trunk/javascript/base64.js?r=230

/*
 * Copyright (c) 2010 Nick Galbreath
 * See full license on http://code.google.com/p/stringencoders/source/browse/#svn/trunk/javascript
 */

var base64 = {};
base64.PADCHAR = '=';
base64.ALPHA = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

base64.makeDOMException = function() {
    // sadly in FF,Safari,Chrome you can't make a DOMException
    var e, tmp;

    try {
        return new DOMException(DOMException.INVALID_CHARACTER_ERR);
    } catch (tmp) {
        // not available, just passback a duck-typed equiv
        // https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/Error
        // https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/Error/prototype
        var ex = new Error("DOM Exception 5");

        // ex.number and ex.description is IE-specific.
        ex.code = ex.number = 5;
        ex.name = ex.description = "INVALID_CHARACTER_ERR";

        // Safari/Chrome output format
        ex.toString = function() { return 'Error: ' + ex.name + ': ' + ex.message; };
        return ex;
    }
}

base64.getbyte64 = function(s,i) {
    // This is oddly fast, except on Chrome/V8.
    //  Minimal or no improvement in performance by using a
    //   object with properties mapping chars to value (eg. 'A': 0)
    var idx = base64.ALPHA.indexOf(s.charAt(i));
    if (idx === -1) {
        throw base64.makeDOMException();
    }
    return idx;
}

base64.decode = function(s) {
    // convert to string
    s = '' + s;
    var getbyte64 = base64.getbyte64;
    var pads, i, b10;
    var imax = s.length
    if (imax === 0) {
        return s;
    }

    if (imax % 4 !== 0) {
        throw base64.makeDOMException();
    }

    pads = 0
    if (s.charAt(imax - 1) === base64.PADCHAR) {
        pads = 1;
        if (s.charAt(imax - 2) === base64.PADCHAR) {
            pads = 2;
        }
        // either way, we want to ignore this last block
        imax -= 4;
    }

    var x = [];
    for (i = 0; i < imax; i += 4) {
        b10 = (getbyte64(s,i) << 18) | (getbyte64(s,i+1) << 12) |
            (getbyte64(s,i+2) << 6) | getbyte64(s,i+3);
        x.push(String.fromCharCode(b10 >> 16, (b10 >> 8) & 0xff, b10 & 0xff));
    }

    switch (pads) {
    case 1:
        b10 = (getbyte64(s,i) << 18) | (getbyte64(s,i+1) << 12) | (getbyte64(s,i+2) << 6);
        x.push(String.fromCharCode(b10 >> 16, (b10 >> 8) & 0xff));
        break;
    case 2:
        b10 = (getbyte64(s,i) << 18) | (getbyte64(s,i+1) << 12);
        x.push(String.fromCharCode(b10 >> 16));
        break;
    }
    return x.join('');
}

base64.getbyte = function(s,i) {
    var x = s.charCodeAt(i);
    if (x > 255) {
        throw base64.makeDOMException();
    }
    return x;
}

base64.encode = function(s) {
    if (arguments.length !== 1) {
        throw new SyntaxError("Not enough arguments");
    }
    var padchar = base64.PADCHAR;
    var alpha   = base64.ALPHA;
    var getbyte = base64.getbyte;

    var i, b10;
    var x = [];

    // convert to string
    s = '' + s;

    var imax = s.length - s.length % 3;

    if (s.length === 0) {
        return s;
    }
    for (i = 0; i < imax; i += 3) {
        b10 = (getbyte(s,i) << 16) | (getbyte(s,i+1) << 8) | getbyte(s,i+2);
        x.push(alpha.charAt(b10 >> 18));
        x.push(alpha.charAt((b10 >> 12) & 0x3F));
        x.push(alpha.charAt((b10 >> 6) & 0x3f));
        x.push(alpha.charAt(b10 & 0x3f));
    }
    switch (s.length - imax) {
    case 1:
        b10 = getbyte(s,i) << 16;
        x.push(alpha.charAt(b10 >> 18) + alpha.charAt((b10 >> 12) & 0x3F) +
               padchar + padchar);
        break;
    case 2:
        b10 = (getbyte(s,i) << 16) | (getbyte(s,i+1) << 8);
        x.push(alpha.charAt(b10 >> 18) + alpha.charAt((b10 >> 12) & 0x3F) +
               alpha.charAt((b10 >> 6) & 0x3f) + padchar);
        break;
    }
    return x.join('');
}