A quick hack to parse NEA Website for latest PSI figures using vanilla nodejs (without plugins). Written 19 June 2013 while choking on Indonesian haze and waiting for code to compile. --Xofel.

psi.js

/* File: psi.js
A quick hack to parse NEA Website for latest PSI figures using vanilla nodejs (without plugins).
Written 19 June 2013 while choking on Indonesian haze and waiting for code to compile. --Xofel.
*/

var http = require("http");
var util = require("util");

var isNumber = function (n) {
  return !isNaN(parseFloat(n)) && isFinite(n);
};

var padTime = function (s) {
  while (s.length != 4) {
		s += "0";
	}
	return s;
};

var html = ""
var request = http.get("http://app2.nea.gov.sg/anti-pollution-radiation-protection/air-pollution/psi/psi-and-pm2-5-readings", function (res) {
	res.setEncoding("utf8");
	
	res.on("data", function (chunk) {
		html += chunk;
	});
	
	res.on("end", function () {
		// Extract the <table> tag containing the data we want.
		var tableStart = html.indexOf("<table");
		var tableStartTagEnd = html.indexOf(">", tableStart);
		var tableEnd = html.indexOf("</table>", tableStart);
		var psiTable = html.substring(tableStartTagEnd + 1, tableEnd).trim();
		var dataStart = psiTable.indexOf("</thead>") + 8;
		var data = psiTable.substring(dataStart).trim();
		
		var psiValues = new Array();
		var valueIndex = 0;
		var lastNumeric = 0;
		var samples = 0;
		var sum = 0;
		var max = 0;
		var min = 1000; // If it can get higher than this we're fucked anyway.
		for (var i = 0 ; i < 4; i++) {
			var rowEnd = data.indexOf("</tr>");
			
			if (i % 2 != 0) {
				var rowBegin = data.indexOf(">");
				var row = data.substring(rowBegin + 1, rowEnd).trim();
				
				for (var j = 0; j < 13; j++) {
					var colEnd = row.indexOf("</td>");
					
					if (j != 0) {
						var colBegin = row.indexOf(">");
						var col = row.substring(colBegin + 1, colEnd).trim();
						
						if (isNumber(col)) {
							lastNumeric = valueIndex;
							
							// Statistics.
							val = parseFloat(col);
							samples++;
							sum += val;
							if (val > max) max = val;
							if (val < min) min = val;
						}
						psiValues[valueIndex++] = col;	
					}
					
					row = row.substring(colEnd + 5).trim();
				}
			}
			
			data = data.substring(rowEnd + 5).trim();
		}
		
		console.log("The latest PSI is " + psiValues[lastNumeric] + " measured at " + padTime(lastNumeric) + "hrs.");
		console.log("Mean PSI: " + (sum / samples) + " (" + samples + " samples)");
		console.log("Max PSI: " + max);
		console.log("Min PSI: " + min);
		console.log("Source: National Environment Agency (www.nea.gov.sg)");
	});
});