Node.js program. parseHTML and get Image files to save it.

getImages.js

/* node getImages.js http://www.yahoo.co.jp */ 

var htmlparser = require('htmlparser');
var sys  = require('sys');
var http = require('http');
var fs   = require('fs');
var url  = require('url');
var path = require('path');

if(process.argv.length !== 3){
    console.log('arguments error.');
    return;
}
var parsedUrl = url.parse(process.argv[2]);
if(parsedUrl.host == null){
    console.log('URL parsed Error.(' + process.argv[2] + ')');
    return;
}

var httpClient = http.createClient(parsedUrl.port ? parsedUrl.port : 80, parsedUrl.hostname);
var request = httpClient.request('GET', parsedUrl.pathname, parsedUrl);
request.end();

var html = [];
request.on('response', function(res){
    console.log("->Start");
    console.log('STATUS : ' + res.statusCode);
    console.log('HEADER : ' + JSON.stringify(res.headers));
    res.setEncoding('utf8');
    res.on('data', function(chunk){
        html.push(chunk);
    });
    res.on('end', function(){
        console.log("->End");
        var myhtmlparser = new MyHtmlParser(parsedUrl);
        myhtmlparser.parse(html.join(''));
        myhtmlparser.getImageElements({tagName:'img'});
        // myhtmlparser.getImageElements({tagName:'a'});
        for(var i=0,imax=myhtmlparser.urls.length; i<imax; i++){
            console.log(myhtmlparser.urls[i]);
            myhtmlparser.getImage(url.parse(myhtmlparser.urls[i]), writeImageFile);
        }
    });
});

function writeImageFile(imageData, fname){
    var imagedir = 'imagedir';
    // var writeStream = fs.createWriteStream(fname, {flags:'w', encoding:null, mode:066});

    // writeStream.on('open',function(){
    //     console.log('writeStream : open');
    //     console.log(arguments);
    //     writeStream.write(imageData, 'binary');
    //     // sys.pump(imageData, writeStream);
    //     writeStream.end();
    // });

    // writeStream.on('close',function(){
    //     console.log('writeStream : close');
    // });

    fs.stat(imagedir, function(error, stat){
        if(error){
            fs.mkdirSync(imagedir, 0766);
        }
        fs.writeFile(imagedir + '/' + fname, imageData, 'binary', function(error){
            if(error){
                console.log(error);
            }
        });
    });

}


/* -------------------------------------------------------- */
var MyHtmlParser = function(parsedUrl){
    this.parsedUrl = parsedUrl;
    this.parsedResult = null;
    this.urls = [];
    if (this === global){
		throw new Error("Error this is global.");
    }
    this.handler = new htmlparser.DefaultHandler(function (error, dom) {
        if(error){
            sys.debug("Error : " + error);
        }
    });
    return this;
};
MyHtmlParser.prototype.parse = function(html){
    var parser = new htmlparser.Parser(this.handler);
    parser.parseComplete(html);
    this.parsedResult = this.handler.dom;
};
MyHtmlParser.prototype.getImageElements = function(option){
    option = option == null ? { tagName : 'img' } : option;

	var tags = htmlparser.DomUtils.getElements({ tag_name: function(val){
        return val.toLowerCase() === option.tagName ? true : false;
    }}, this.parsedResult);

    var url = null;
    for(var i=1,imax=tags.length; i<imax; i++){
        url = tags[i].attribs && (tags[i].attribs.href || tags[i].attribs.src);

        if(url){
            if(url.match(/.*\.(jpg)$/i)){
                if(url.match(/^http:\/\/.*/)){
                    this.urls.push(url);
                }else{
                    this.urls.push(this.parsedUrl.protocol + '//' +
                                   this.parsedUrl.hostname +
                                   url);
                }
            }
        }
    }
};
MyHtmlParser.prototype.getImage = function(parsedUrl, callback){
    // var body = "";
    var body = [];
    var getImageBind = this.getImage.bind(this);

    http.get({host:parsedUrl.host, path:parsedUrl.pathname},function(res){
        res.setEncoding('binary');
        res.on('data', function(chunk){
            // body += chunk;
            body.push(chunk);
        });
        res.on('end', function(){
            if(res.statusCode === 302){
                body = getImageBind(url.parse(res.headers.location), callback);
            }else if(res.statusCode === 200){
                callback(body.join(''), parsedUrl.pathname.match(".+/(.+?)$")[1]);
                // callback(body, parsedUrl.pathname.match(".+/(.+?)$")[1]);
            }else{
                console.log(' -> ' + res.statusCode);
            }
        });
    });
    // console.log('finish->');
};