getstatus.js

// 1st thing I should've done is write down the question

// Q: Do REST call, process response body and print O.K if all params are true else print Error: some_param and exit.
//    Response format: multi-lines ascii: "- attr_name_string : bool"

// 2nd, beside choosing just about any other language than node.js because it is very hard to do this in node...
// find a proper example of node.js http.get client code such as:
// http://stackoverflow.com/questions/6968448/where-is-body-in-a-nodejs-http-get-response
// and remember that res.on('data', function(chunk) { ... })

// FYI, Not true what I said about console.dir I mixed up with Python dir() :-/


// node.js HTTP Client/Server API
var http = require("http");

// Call cb with a Status String after doing asynchronous HTTP GET of url
getStatus = function(url, cb) {
    var status = "Status O.K." // NOTE: If we receive empty response or no "param" are found we return "STATUS O.K." !
    
    http.get(url, function(res) {
	console.log("HTTP response: " + res.statusCode);

	res.on('data', function(chunk) {
	    // This is tricky because http response may call 'data' many times before it call 'end'...
	    console.log("HTTP DATA chunk: " + chunk);

	    var processedStatus = _processStatus(chunk);
	    if( processedStatus ) {
		// Non null means we got a new valid Status String
		status = processedStatus;
	    }
	});
	res.on('end', function() {
	    // Callback with status string: "Status O.K." or "Status Error: param_name"
	    cb(url, status);
	});
	
    }).on('error', function(e) {
	var err = "HTTP error: " + e.message
	cb(url, err);
    });
}
	     
_processStatus = function(chunk) {
    var data = chunk.toString('utf8');

    if( data ) {
	var lines = data.split('\n');
	for(var i=0; i < lines.length; i++) {
	    if( lines[i] ) {
		var rows = lines[i].split(' ');
		for( var j=0; j < rows.length; j++) {
		    if( rows[0] == '-' && rows[2] == ':' ) {
			var name = rows[1];
			var value = rows[3];

			console.log("_processStatus ATTR NAME: " + name + " VALUE: " + value);

			// Process ATTR:
			if( ! value ) {
			    return "Status Error: " + name;
			} else {
			    console.log("Status ATTR: " + name + " is O.K.");
			    return "Status O.K."
			}
		    } else {
			// ERR! WRONG FORMAT (return empty string)
			return "";
		    }
		}
	    }
	    // else ==> skip empty line.
	}
    }
    // else ==> no data, do nothing.
}


// MAIN
var urls = ["http://www.google.com", "http://www.yahoo.com"];
var status = [];
var req_cnt = 0;
var res_cnt = 0;

for(var i=0; i < urls.length; i++) {
    req_cnt = req_cnt + 1;
    getStatus(urls[i], function(url, res) {
	res_cnt = res_cnt + 1;
	status[i] = res;
	console.log("URL: " + url + " STATUS: " + res);
    });
}

var wait_for_all_responses = function(cb) {
    if( res_cnt != req_cnt ) {
	// Wait a sec...
	setTimeout(function() {
	    wait_for_all_responses(cb);
	}, 1000);
    } else {
	// We're done! CALLBACK
	cb();
    }
}
	
var were_done = function() {
    console.log("We're done! Here are the " + res_cnt + " URL:STATUS RESPONSE(s):\n");
    for(var i=0; i < res_cnt; i++) {
	console.log(urls[i] + ":" + status[i]);
    }
}

// Wait for all requests to finish:
wait_for_all_responses(were_done);