Getting Google Page Rank using Javascript – For Adobe AIR Apps

Last week while working on SEO Analyzer v 1.1 desktop application, I faced a challenge of getting google page rank for a particular site using javascript. I am not sure if someone has already done this before, but I thought of sharing this javascript code for all adobe air and web developers out there.

googlepagerank.js

var googlepagerank = {
	hexdec: function(hex_string) {
	    hex_string = (hex_string+'').replace(/[^a-f0-9]/gi, '');
	    return parseInt(hex_string, 16);
	},
	count: function( mixed_var, mode ) {
	    var key, cnt = 0;
	    if( mode == 'COUNT_RECURSIVE' ) mode = 1;
	    if( mode != 1 ) mode = 0;
	    for (key in mixed_var){
	        cnt++;
	        if( mode==1 && mixed_var[key] && (mixed_var[key].constructor === Array || mixed_var[key].constructor === Object) ){
	            cnt += count(mixed_var[key], 1);
	        }
	    }
	    return cnt;
	},
	sizeof: function( mixed_var, mode ) {
	    return googlepagerank.count( mixed_var, mode );
	},
	ord: function(string) {
	    return (string+'').charCodeAt(0);
	},
	strlen: function(string) {
	    var str = string+'';
	    var i = 0, chr = '', lgth = 0;
	    var getWholeChar = function (str, i) {
	        var code = str.charCodeAt(i);
	        var next = '', prev = '';
	        if (0xD800 <= code && code <= 0xDBFF) {
	            if (str.length <= (i+1))  {
	                throw 'High surrogate without following low surrogate';
	            }
	            next = str.charCodeAt(i+1);
	            if (0xDC00 > next || next > 0xDFFF) {
	                throw 'High surrogate without following low surrogate';
	            }
	            return str[i]+str[i+1];
	        } else if (0xDC00 <= code && code <= 0xDFFF) {
	            if (i === 0) {
	                throw 'Low surrogate without preceding high surrogate';
	            }
	            prev = str.charCodeAt(i-1);
	            if (0xD800 > prev || prev > 0xDBFF) {
	                throw 'Low surrogate without preceding high surrogate';
	            }
	            return false;
	        }
	        return str[i];
	    };
	    for (i=0, lgth=0; i < str.length; i++) {
	        if ((chr = getWholeChar(str, i)) === false) {
	            continue;
	        }
	        lgth++;
	    }
	    return lgth;
	},
	substr: function(f_string,f_start,f_length ) {
			f_string += '';
			if(f_start < 0) {
					f_start += f_string.length;
			}
			if(f_length == undefined) {
					f_length = f_string.length;
			} else if(f_length < 0){
					f_length += f_string.length;
			} else {
					f_length += f_start;
			}
			if(f_length < f_start) {
					f_length = f_start;
			}
			return f_string.substring(f_start, f_length);
	},
	zeroFill: function(a, b){
		z = googlepagerank.hexdec(80000000);
		if (z & a) {
			a = (a >> 1);
			a &= (~ z);
			a |= 0x40000000;
			a = (a >> (b - 1));
		}
		else {
			a = (a >> b);
		}
		return a;
	},
	mix: function(a, b, c){
		a -= b; a -= c; a ^= (this.zeroFill(c, 13));
		b -= c; b -= a; b ^= (a << 8);
		c -= a; c -= b; c ^= (this.zeroFill(b, 13));
		a -= b; a -= c; a ^= (this.zeroFill(c, 12));
		b -= c; b -= a; b ^= (a << 16);
		c -= a; c -= b; c ^= (this.zeroFill(b, 5));
		a -= b; a -= c; a ^= (this.zeroFill(c, 3));
		b -= c; b -= a; b ^= (a << 10);
		c -= a; c -= b; c ^= (this.zeroFill(b, 15));
		return new Array(a, b, c);
	},
	ch: function(url){
		length = googlepagerank.sizeof(url);
		a = 0x9E3779B9;
		b = 0x9E3779B9;
		c = 0xE6359A60;
		k = 0;
		len = length;
		while (len >= 12) {
			a += (url[k + 0] + (url[k + 1] << 8) + (url[k + 2] << 16) + (url[k + 3] << 24));
			b += (url[k + 4] + (url[k + 5] << 8) + (url[k + 6] << 16) + (url[k + 7] << 24));
			c += (url[k + 8] + (url[k + 9] << 8) + (url[k + 10] << 16) + (url[k + 11] << 24));
			m = this.mix(a, b, c);
			a = m[0]; b = m[1]; c = m[2];
			k += 12;
			len -= 12;
		}
		c += length;
		switch (len) {
			case 11: c += (url[k + 10] << 24);
			case 10: c += (url[k + 9] << 16);
			case 9:  c += (url[k + 8] << 8);
			case 8:  b += (url[k + 7] << 24);
			case 7:  b += (url[k + 6] << 16);
			case 6:  b += (url[k + 5] << 8);
			case 5:  b += (url[k + 4]);
			case 4:  a += (url[k + 3] << 24);
			case 3:  a += (url[k + 2] << 16);
			case 2:  a += (url[k + 1] << 8);
			case 1:  a += (url[k + 0]);
		}
		m = this.mix(a, b, c);
		return m[2];
	},
	strord: function(string){
		var result = new Array();
		for (i = 0; i < googlepagerank.strlen(string); i++) {
			result[i] = googlepagerank.ord(string[i]);
		}
		return result;
	},
	gethash: function(url) {
		return this.ch(this.strord("info:" + url));
	},
	getpr: function(baseurl) {
		var query = "";
		query += "http://toolbarqueries.google.com/search";
		query += "?client=navclient-auto";
		query += "&hl=en";
		query += "&ch=6"+googlepagerank.gethash(baseurl);
		query += "&ie=UTF-8";
		query += "&oe=UTF-8";
		query += "&features=Rank";
		query += "&q=info:"+baseurl;

		var req = new XMLHttpRequest();
		req.onreadystatechange = function(){
			if (req.readyState == 4) {
				var str = req.responseText;
				var pagerank = googlepagerank.substr(str, 9, 2);
				alert(pagerank);
			}
		}
		req.open('GET', query, true);
		req.send(null);
	}
}

How to use script in an adobe air application

How to use script in an web applications
This script cannot be used directly for web applications, mainly because of cross domain XHR limitations. However the script can be modified to use with proxy script provided at developer.yahoo.com

Please Note: Getting google page rankings is/might be illegal as per google's policy. If you use this script from webservers, possibilities are google might block your server IP Address. However with adobe air applications (desktop apps), risk is minimized.

Enjoy and Do leave a comment.