Utilities for NodeJS

• Installation
• Usage
• Packages:
  • String
  • Number
  • Array
  • Date
  • File
  • Url
  • Cache
  • Properties
  • Geo
• Code samples

Installation

			npm install nodutils

Usage

			var utils = require("nodutils");

String

• utils.string.trim(str) or String.trim()

• utils.string.ltrim(str) or String.trim()

• utils.string.rtrim(str) or String.trim()

• utils.string.toi(str) or String.toi()

  • Converts to integer
    

• utils.string.tof(str[,decimals]) or String.tof([decimals])

  • Converts to float, with number of decimals
    

• utils.string.dropDiacritics(str) or String.dropDiacritics()

  • Converts accents, diacritics into a plain letter
    

• utils.string.isNumber(str) or String.isNumber()

• utils.string.stripHtml(str) or String.stripHtml()

  • Strip all html tags and leaves only text
    

• utils.string.count(str,substr[,flags]) or String.count(substr[,flags]).

  • It counts the number of ocurrences of substr. Flags can be "i" (ignore case) and/or "d" (drop accents)
    

• utils.string.reverse(str) or String.reverse()

• utils.string.toHtml(str) or String.toHtml()

  • Converts diacritics and almost all chars into html entities
    

• utils.string.fromHtml(str) or String.fromHtml()

  • Converts into diacritics html encoded entities

Number

• utils.number.round(num[,decimals]) or Number.round([decimals])

  • Rounds number to the given number of decimals

Array

• utils.array.max(array) or Array.max()

  • Returns the max value in an array of numbers
    

• utils.array.min(array) or Array.min()

  • Returns the min value in an array of numbers
    

• utils.array.uniques(array) or Array.uniques()

  • Returns an array of uniques values in the original array
    

• utils.array.aggregate(array) or Array.aggregate()

  • Returns an array of uniques values and counts its occurrences, sorted descending (sample code)

    	["a","b","c","d",1,2,"a","b","c","a","b","a",1,0,1].aggregate();
    
    	returned array
    	
    	[ [ 'a', 4 ], [ '1', 3 ], [ 'b', 3 ], [ 'c', 2 ], [ '0', 1 ], [ '2', 1 ], [ 'd', 1 ] ]
    

• utils.array.contains(array,value[,flags]) or Array.contains(value[,flags])

  • Returns true or false

  • Flags can be "i" (ignore case) and/or "d" (drop accents)
    

Date

• utils.date.diff(date1,date2[,unit])

  • Unit = "d": days,"h": hours,"m": minutes,"s": seconds. Default unit is millis
    

• utils.date.millis([date])

  • Returns a timestamp in millis from current date or date passed as param (string or date object)
    

• utils.date.frommillis(millis)

  • Returns a date object from millis passed as parameter

File

• utils.file.write(file,data[,options],function(err){})

  • options = "w" write or "a" append
    

• utils.file.read(file[,encoding],function(err,data){})

• utils.file.exists(file,function(exists){})

  • exists: true or false

• utils.file.getModTime(file,function(date){})

  • Date object is given to the callback as an argument
    

• utils.file.remove(file,callback)

• utils.file.createpath(path,callback)

Url

			//get sample
			utils.url.get("www.bbc.com",function(html){
				if(html){
					console.log(html);
				}
			});			

			//post sample
			utils.url.post('httpbin.org/post',{post_data:{data:'lorem ipsum dolor sit amet'}}, 
				function(resp){
					if(resp){
						console.log(resp);
					}
				}
			);

• utils.url.get(url[,options],function(content,statuscode,headers){})

• utils.url.post(url[,options],function(content,statuscode,headers){})

  • Support for http and https

  • Support for proxy requests (in url. E.g: "url"=http://www.proxy.com:8080/www.urltobeproxied.com)

  • It is possible to set only url or options, but options need to set host, path, ...

  • Options is an object with some props:

    • "encoding" default is "utf-8"

    • "post_data" (for post()) is an object

      with the vars (post_data:{a:1,b:2})

      or with the body in "data" key (post_data:{data:"whatever"})

    • "headers" (object)

    • "auth" (string)

    • "forceparse": if the url is with proxy data is better to set to true

Cache

• utils.cache.getPath()

  • Get the current cache dir (default is "./cache")
    

• utils.cache.setPath(path,callback)

  • Set the cache dir (and create if it doesn't exists)

  • It's recommended to use absolute paths ("/apps/myapp/cache")
    

• utils.cache.setOptions({path : "/mypath", size : 1}},callback)

  • Set the cache dir (and create if it doesn't exists) and cache max size

  • Cache size is in MB
    

• utils.cache.set(key,data[,expiretime],callback)

  • Expiretime is in seconds. If not informed, then unlimited
    

• utils.cache.get(key,function(value){})

• utils.cache.remove(key,callback)

(sample code)

Properties

• utils.props.load(path_to_file,function(props){})

  • properties in the file are loaded into a JSON object passed in callback

  • Format of the properties file is

      	key1=value1
      	key2=value2
      	key3=value3
      	key4=123456789
    

• utils.props.save(path_to_file,properties,callback)

  • properties param is a json object. You can save properties dynamically

Geo

Utilities for basic geocoding and checking distance between points. Limited to Google and Yahoo API limits, but you could geocode 50.000 addresses/points for Yahoo and 2.500 for Google. Utils.geo will use one or other depending of availability of the service. (sample code)

• utils.geo.getDistance(point1,point2[,earthRadius])

  • Calculates the distance between point1 and point2. Points are arrays: [latitude,longitude]

  • Distance is in km.

  • earthRadius default is 6371 km.
    

• utils.geo.isInside(point,center,radius[,earthRadius])

  • Checks if a point (array of two positions [latitude,longitude]) is inside a circle (center + radius). Center is an array of two positions.

  • radius is in KM

  • earthRadius default is 6371 km.
    

• utils.geo.geocode(address,options,callback)

  • Returns an array of two positions [latitude,longitude] for the given address.
    

• utils.geo.rgeocode(latitude,longitude,options,callback)

  • Reverse geocode. Returns an object for the given latitude and longitude.
    

Both, geocode and rgeocode return the same object

			{ 
				number : 'xxxxxxxxxxxx',
				street: 'xxxxxxxxxxxx',
				postal: 'xxxxxxxxxxxx',
				city: 'xxxxxxxxxxxx',
				county: 'xxxxxxxxxxxx',
				state: 'xxxxxxxxxxxx',
				country: 'xxxxxxxxxxxx',
				lat: 1.11,
				lon: 2.22 
			}

You can set the locale in the options object {"locale" : "en_GB"}

Samples

• Caching twitter request due to twitter api limits (it uses url and cache utilities)

  		var utils = require("nodutils");
  		var twitterquery = "davidayalas";
  		var twitterurl = "http://api.twitter.com/1/statuses/user_timeline.json?screen_name=";
  
  		utils.cache.get(twitterquery, function(content){
  			if(!content){
  				utils.url.get(twitterurl+twitterquery,function(result){
  					utils.cache.set(twitterquery,result,300);
  					console.log(result);
  				});
  			}else{
  				console.log(content);
  			}
  		});
  

• Easy "tagcloud" from url content (it uses url, string and array utilities)

    		var utils = require("nodutils");
  
    		utils.url.get("www.bbc.com",function(content){
    			var topwords = [];
    			if(content){
    				var topwords = content.stripHtml().split(" ").aggregate().filter(function(i){
    					return i[0].length<=3 || i[0].indexOf("&")>-1?false:true;
    				}).slice(0,50);
    			}
    			console.log(topwords);
    		});  
  

• Calculate the distance between two unestructured addresses (it uses geo)

    		var utils = require("nodutils");
  
    		utils.geo.geocode("madrid,spain", function(p1){
    			utils.geo.geocode("barcelona,spain", function(p2){
    				console.log("distance between Madrid and Barcelona is: ");
    				if(p1 && p2){
    					console.log(utils.geo.getDistance([p1.lat, p1.lon],[p2.lat, p2.lon]) + " km");
    				}
    			});
    		});
  

• Simple http server for caching and serve only valid twitter users (stored in properties file)

• Bulk geocode from url content. Tested with more than 5000 addresses. (it uses geo, url, string, file)

    		var utils = require("nodutils");
  
    		utils.url.get("http://w20.bcn.cat/opendata/DonaRecurs.aspx?arbre=general&recurs=TAULA_CARRERS&fitxer=1121",{"encoding":"iso-8859-1"}, function(content,code){
    			if(content){
    				content.split("\r\n").forEach(
    					function(element, index, array){
    						var add = element.slice(element.lastIndexOf(";")+1);
    						if(add){	
    							utils.geo.geocode((add.count("carrer","i")>0?add:"Carrer "+add)+",barcelona,spain", function(p){
    								if(p && typeof(p)=="object" && p.lat && p.lon){
    									console.log(element + ";" + p.lat + ";" + p.lon);
    									utils.file.write(__dirname + "/geocoded-addresses.txt", element + ";" + p.lat + ";" + p.lon + "\r\n", "a");
    								}
    							});
    						}
    					}
    				);
    			}
    		});