Category: idea

wrapper for google static map api

October 31, 2008 ·

google maps is one of the very best mapping services available these days. using their api you can embed interactive maps of different types in your web pages. and there are many plugins to make your life easier to embed such maps in your web pages and applications.

to embed interactive google map, you need to include some external javascript files first. now when you are using some hosted solutions like wordpress, they may not allow you to include external javascript files in your blog/pages for different security pre-cautions. this is where google static map api comes handy.

google static maps api takes latitude and longitude of some places as parameter, along with other optional formatting params and delivers a static image in your expected image format (default is gif, but you can choose among gif, png and jpeg). so you dont need to bother about permission of including any other javascript files in your pages and you can embed such static maps by specifying the url as a “src” attribute of <img> tag.

there is still one problem that might knock you down. for example if you want to display “dhaka”, the capital or bangladesh in your static map, you need to know it’s latitude and longitude. so not everyone of us speaks in a language of ‘latitude’ and ‘longitude’ but onle the name of the places. like we all know about “university of berkeley” but only very few can figure out it’s lat-lon or they have to find it out from existing geocoding services.

yesterday night i was studying about this static map api and decided to build a geocoding wrapper so that you can pass only the name of a place and my wrapper class will convert it to latitude and longitude using geociding services and then generate a static map image for you. the whole wrapper will work around two objects – geocoding service and google static map api. for geocoding i prefer to use google because of it’s amazing precision but i must say that yahoo’s geocoding service is also pretty good.

here is my wrapper class and i am sure you can find it useful. now you can use it to embed google map to anywhere you would like to :). this class is released under LGPL.

there is a sample usage file (gmap.php which you will make use of) and a source object “staticgmap.php”. this class became a part of orchid framework and prothom alo blog. if you enjoy/use this class, dont forget to drop a line here in this post. the class and usage file is moderately commented, so you will not face any problem to understand. however the usage file is also pretty fine working.

please download the class from this page
download: http://svnpg.net/gmap/

supported features
1. geocoding service, both yahoo and google (default is yahoo)
2. support of zooming (0-19, default is 12)
3. support of image format (gif, jpeg and png. default is GIF)
4. maptype support (roadmap, satellite, mobile, hybrid and terrain where default is roadmap)
5. support of markers (just as plain location name)
6. variable dimension support (default size is 400×400)

sample maps

locate dhaka and moti jheel
http://svnpg.net/gmap/gmap.php?location=dhaka&markers=dhaka,moti jheel
dhaka and motijheel marked on a static google map

locate berkeley and emeryvlle
http://svnpg.net/gmap/gmap.php?location=berkeley&markers=berkeley,emeryville&zoom=11
berkeley and emeryville marked on google static map

place where i live – uttara 14 with custom zoom level and custom size
http://svnpg.net/gmap/gmap.php?location=uttara 14&zoom=16&size=400×300

Look Ma, everyone's computing out there for me!

June 6, 2008 ·

SETI@Home is probably the greatest example of low cost distributed computing which become a big hit. After their tremendous success, many others over there started following the same strategy and used the power of distributed computing for other purposes like cancer research. In this article I will show you how we can use the same power at almost zero cost, and specially for your web applications.

As I am currently working on building an open source version of FriendFeed (not targetted to be an alternative, coz those people at FriendFeed done their job really well) and scaling such a huge load effectively at low cost, so I will mainly talk more about FriendFeed through out this blog post and use it as an example for my proposal.

If you consider FriendFeed as a repository of feed URLs, a lot of peoples and how they are related to each other, you can assume how big it is or it could be in near future. And scaling such a service would cost numbers of sleepless nights of many developers out there. So in basic, lets focus where actually the problem is and how we can introduce distributed computing.

Beside optimizing database to serve huge sets of data, one of the main problems of such a service has to parse millions of feeds in a regular interval. If we want to bear all the loads on your server, fine, if you can afford. But what about some low cost solutions. Lets consider a simple scenario, if your application has one million of users and each of them browse your application for 10 minutes a day, you really have 10 millions of computational power just wasting over there, in lanes and by lanes of internet – heh heh. So lets make use of such an incredible CPU power. All you have to do let the visitors machine do some calculations for you and free your server from gigantic load.

When the users of your application and relation among them are stored in your database, you can easily find out the first degree and second degree friends of a specific user. If you don’t know what does that mean, its simple, If A is a friend of B and C is a friend of A, then A is B’s first degree friend and C is B’s second degree friend. For a huge social network, it may look like the following one when you visualize the relationship

image courtesy: http://prblog.typepad.com

Now what we want to do is when B is visiting our application we want to parse most of his/her second degree friends in client using his browser. So while generating the page for B, we will supply him a bunch of feed URLs, a hash of their last known update time or hash of the latest item of each of these corresponding feeds, and a javascript based parser (for example Google’s ajax Feed API would do fine) script. Now, while B is browsing our application we will parse those feeds of his second degree friends using javascript without bothering him for a single second and post back the parsed contents (after checking against the hash for really updated contents) to a server side script which will then blindly (not totally, after some validation or authentication for sure) insert those result to our database. Now when A comes and visit his page (A is C’s first degree friend), he will get all the latest result from C’s feeds as B has already done the parsing job for us and we have those latest result from C’s feeds stored in our Database.

There are definitely more challenge than it is explained here, like what if a person is second degree friend of a multiple user. In such cases as we supplied last update time of these feeds while generating a page, we can calculate from server side which feeds we really want to parse.

And moreover, we can add more check for our javascript parser than just blindly parse those feeds. We can download a chunk of RSS or Atom feeds (using a proxy script developped using curl range options) and read just up to the latest update time and extract the time using simple reg ex or string functions instead of downloading full feed data. Now if we know that a script is not uptodate just by downloading 1-2 killobyte of data instead of downloading full feed, parsing the xml data, it would save us more computing resources for performing other jobs.

But of course, you cannot live completely on your client’s machine for parsing all your data. You must have several cron’d scripts to parse left overs or other feeds at server side. But what I am saying is that with little help of javascript you can make use of such a tremendous distributed computing power in your application, all at almost no cost.

I will come with example code once I am done developing my open source clone of FriendFeed and then I am sure, you will find it was worth writing a blog post about.

Distributed Computing
image courtesy: http://www.naccq.ac.nz/bacit/0203/2004Caukill_OffPeakGrid.htm

Have a nice RnDing time. 🙂

Building services like FriendFeed using PHP – Part2

June 3, 2008 ·

Following the first installment in this series, here is the second part. In this part I will focus mainly on Bookmarking and News services supported by FriendFeed . Here we go

Supported bookmarking services by FriendFeed
1. Del.icio.us
2. Furl
3. Google shared stuffs
4. Mag.nolia
5. Stumbleupon

Except google shared stufss, all of the rests require just an username to generate the access point for retrieving user’s bookmarked items. And for the google shared stuffs, it requires the fully functional url of the feed available from your google bookmark service.

Access points

Del.icio.us

AP: http://feeds.delicious.com/rss/<user name>
example: http://feeds.delicious.com/rss/anduh

Furl

AP: http://rss.furl.net/member/<user name>.rss;
example: http://rss.furl.net/member/pigge.rss

Google Shared Stuffs
you can find your google shared stuff url from http://www.google.com/s2/sharing/stuff

example: http://www.google.com/s2/sharing/stuff?user=110703083499686157981&output=rss

Ma.gnolia

AP: http://ma.gnolia.com/rss/lite/people/<user name>.rss;
example: http://ma.gnolia.com/rss/lite/people/gerryquach

Stumbleupon
Whoops, Double Whoops, Tripple Whoops. It took quite a time for me to find the feed url. I dont know why it is kept so “SECRET” – LOL

AP: http://www.stumbleupon.com/syndicate.php?stumbler=<user name>.rss;
example: http://www.stumbleupon.com/syndicate.php?stumbler=jd001

Supported news services by FriendFeed
1. Digg
2. Google Reader
3. Mixx
4. Reddit

Here are the access points

Digg

AP: http://digg.com/users/<user name>/history.rss;
example: http://digg.com/users/msaleem/history.rss

Google Reader

You can find your shared item’s feed url here http://www.google.com/reader/view/user/-/state/com.google/broadcast

Mixx

Unfortunately during the time of writing this article, Mixx was napping – here is the screenshot. Once they are awake, I will update this section 🙂

Reddit

AP: http://www.reddit.com/user/<user name>/.rss;
example: http://www.reddit.com/user/jack_alexander/.rss

In next installation I will focus on scaling such a huge load successfully. Hope that will be interesting to many of you. Following installation will focus again on the access points.

Building services like FriendFeed using PHP – Part 1

May 31, 2008 ·

Friendfeed is an excellent life streaming service aggregating all your feeds from different service providers, compile them together, build a social network among your known people and finally deliver all these feeds as a mashup. As a result you can immediately track activities of your friends on all the different service they use (like jaiku, twitter, flickr) and stay up-to-date. Hats off to the developers of FriendFeed for delivering such a nice application to us.

In this blog post I will try to focus on how to develop such a service like Friendfeed using PHP and JS and how to scale such a huge load successfully. Previously I’d also written another article focusing “How to develop services like SpringLoops using PHP“. The complete article will be delivered in multiple installments and in current installment, I will focus on Photo sharing services used by friendfeed.

Area to focus
1. Services to be supported
2. Update discovery
3. Parsing the feeds
4. Storing the data
5. Scaling

FriendFeed parses feeds from a total of 35 popular services from around the web 😉 – lets have a look at them one by one and I will give you idea about the access points of these services. Though Not all of them are feed, so I will try to focus those services as well to give you a basic idea.

Service 1 : Flickr
Usable PHP Library: PHPFlickr

Flickr is an excellent photo sharing services under the banner of Yahoo. Friendfeed parses all the photo from a user and also the list of his/her favorite photos. Given an username you can easily find the Flickr ID like (76536911@N00)of that user and once you got it, here is the access points for list of public photos and favorites

List of photos
http://api.flickr.com/services/feeds/photos_public.gne?id=<user’s flickr id>&lang=en-us&format=rss_200
example: http://api.flickr.com/services/feeds/photos_public.gne?id=76536911@N00&lang=en-us&format=rss_200

List of favorites
http://api.flickr.com/services/feeds/photos_faves.gne?nsid=<user’s flickr id>&lang=en-us&format=rss_200
example:http://api.flickr.com/services/feeds/photos_faves.gne?nsid=76536911@N00&lang=en-us&format=rss_200

Service 2: Picasa Web Album
Picasa is another photo sharing service under the banner of the Giant, Google. Given a picasa user name , here are the access point of user’s public photos

List of public photos
http://picasaweb.google.com/data/feed/base/user/<picasa user name>?kind=album&alt=rss&hl=en_US&access=public
example:http://picasaweb.google.com/data/feed/base/user/countdraculla?kind=album&alt=rss&hl=en_US&access=public

Service 3: Smugmug
Here comes another photo sharing service where users can buy and sell their photos. Given a smugmug user name you can find the feed of this user’s photos

List of public photos
http://<smugmug user name>.smugmug.com/hack/feed.mg?Type=nickname&Data=Ifocus&format=rss200
example:http://ifocus.smugmug.com/hack/feed.mg?Type=nickname&Data=Ifocus&format=rss200

Service 4: Zoomr
Zoomr is another photo sharing service started in late 2005 by Kristopher Tate as a place for him to share photos with his friends and later became a public services, is currently supported by FriendFeed. And here we go with the access points 🙂

List of public photos
http://www.zooomr.com/services/feeds/public_photos/?id=<zoomr user name>&format=rss_200
example:http://www.zooomr.com/services/feeds/public_photos/?id=wolfmank&format=rss_200

In next part, I will highlight the access points of supported bookmark services and news services supported by FriendFeed 🙂 Have a nice weekend.

Web scrapping in a smart way, making a "Today in History" object in PHP

April 29, 2008 ·

There are thousands of services available on web who are presenting interesting as well as education information which you can really integrate in your web page or make a nice widget and let others use them seamlessly with their content delivery platforms. In this article I am going to show you how you can make a nice Today-in-History widget with the help of the data provided in Scopesys. You can use this code to make a nice widget or a trivia app or whatever. But before making your own scrappers from any services, please please please carefully note the copyright of that content. You shouldn’t violate copyright either way.

In this widget, we will strip the following content from the pages provided by scopesys and display them in different categories.
1. Today in history
2. Who’s born today
3. Who’s died today
4. Where is holiday today
5. Religious observance of today
6. Religious history of today

Lets go 😀

<?php //todayinhistory.php error_reporting(0); define("MARKER_START","<H3>On this day...</h3>"); define("MARKER_END","<BR><BR><HR><h3>Holidays</h3>"); define("BIRTHDAY_START","</font></center></center>"); define("BIRTHDAY_END","<HR> <br><H3>Deaths which occurred on ".date("F d").":</H3>"); define("DEATH_START","<HR> <br><H3>Deaths which occurred on ".date("F d").":</H3>"); define("DEATH_END","<HR><IMG align=left SRC=\"http://www.scopesys.com/flag.gif\">"); define("HOLIDAYS_START",'<i>Note: Some Holidays are only applicable on a given <b>"day of the week"</b></i><br> <br>'); define("HOLIDAYS_END","<HR> <H3>Religious Observances</H3>"); define("RELIGIOUS_START","<HR> <H3>Religious Observances</H3>"); define("RELIGIOUS_END","<HR> <H3>Religious History </h3>"); define("RELHISTORY_START","<HR> <H3>Religious History </h3>"); define("RELHISTORY_END","<BR><BR><font color=red>");

echo "<h2>Today is ".Date("F d, Y")."</h2>"; $data = file_get_contents("http://www.scopesys.com/today");

if ($_GET['history']=='1'){ echo "<br/><h2 style='color: green' >Today in history</h2>"; $end = strpos($data,MARKER_END)-15; $start = strpos($data,MARKER_START)+strlen(MARKER_START); echo substr($data,$start,$end-$start); }

if ($_GET['born']=='1'){ echo "<br/><h2 style='color: green' >Who's born today</h2>"; $end = strpos($data,BIRTHDAY_END); $start = strpos($data,BIRTHDAY_START)+strlen(BIRTHDAY_START); echo substr($data,$start,$end-$start); }

if ($_GET['died']=='1'){ echo "<br/><h2 style='color: green' >Who died today</h2>"; $end = strpos($data,DEATH_END); $start = strpos($data,DEATH_START)+strlen(DEATH_START); echo substr($data,$start,$end-$start); }

if ($_GET['holiday']=='1'){ echo "<br/><h2 style='color: green' >Where is holiday today</h2>"; $end = strpos($data,HOLIDAYS_END); $start = strpos($data,HOLIDAYS_START)+strlen(HOLIDAYS_START); echo substr($data,$start,$end-$start); }

if ($_GET['religious']=='1'){ echo "<br/><h2 style='color: green' >Religious observance</h2>"; $end = strpos($data,RELIGIOUS_END); $start = strpos($data,RELIGIOUS_START)+strlen(RELIGIOUS_START); echo substr($data,$start,$end-$start); }

if ($_GET['relhistory']=='1'){ echo "<br/><h2 style='color: green' >Religious history</h2>"; $end = strpos($data,RELHISTORY_END); $start = strpos($data,RELHISTORY_START)+strlen(RELHISTORY_START); echo substr($data,$start,$end-$start); } ?>

Now if you want to find who born today, point your browser to todayinhistory.php?born=1. Mashup Mashup Mashup, that is what many successful web app are doing these days. And sometime this is how data collection is done behind the scene 🙂

Writing this code was really enjoyable as getting root canal done in your teeth with a rusty drill (I forgot where I’ve read such a nice quote), heh heh. But I am sure, you will enjoy it more than that 😉 – happy scrapping.

How to configure Citycell Zoom USB Modem for Linux (EC325)

September 6, 2007 ·

Today I have configured the CDMA USB modem (HUWAEI EC325) provided by citycell with their zoom connection to use in my linux distro (Mandriva Spring 2007) – Heres how to-

Attach the modem with your pc/laptop

1. check if the USB device is detected properly
cat /proc/bus/usb/devices

you will get some output like this

…..
…..
T: Bus=02 Lev=01 Prnt=01 Port=05 Cnt=02 Dev#= 4 Spd=12 MxCh= 0
D: Ver= 1.01 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=16 #Cfgs= 1
P: Vendor=12d1 ProdID=1001 Rev= 0.00
S: Manufacturer=Huawei Technologies
S: Product=Huawei Mobile
S: SerialNumber=HUAWEI EC3X1
C:* #Ifs= 2 Cfg#= 1 Atr=e0 MxPwr=100mA
I: If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=pl2303
E: Ad=81(I) Atr=03(Int.) MxPS= 16 Ivl=128ms
E: Ad=8a(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=0b(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
I: If#= 1 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=pl2303
E: Ad=83(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=06(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
…..
…..

2. Now probe for this USB device
modprobe usbserial vendor=0x12d1 product=0x1001

3. Now check with dmesg if it has been successfully probed
dmesg

you will get some output like this

[ 2315.412106] usbcore: registered new interface driver usbserial
[ 2315.412508] drivers/usb/serial/usb-serial.c: USB Serial support registered for generic
[ 2315.461938] usbcore: registered new interface driver usbserial_generic
[ 2315.461945] drivers/usb/serial/usb-serial.c: USB Serial Driver core
[ 2315.480382] drivers/usb/serial/usb-serial.c: USB Serial support registered for pl2303
[ 2315.480414] pl2303 2-6:1.0: pl2303 converter detected
[ 2315.480608] usb 2-6: pl2303 converter now attached to ttyUSB0
[ 2315.480620] pl2303 2-6:1.1: pl2303 converter detected
[ 2315.480691] usb 2-6: pl2303 converter now attached to ttyUSB1

4. Now configure your wvdial.conf as shown here.
vi /etc/wvdial.conf

[Modem0]
Modem = /dev/ttyUSB0
Baud = 230400
SetVolume = 0
Dial Command = ATDT
Init1 = ATZ
FlowControl = Hardware (CRTSCTS)
[Dialer cdma]
Username = waps
Password = waps
Phone = #777
Stupid Mode = 1
Inherits = Modem0

Now save this file

You are done!!

Now you can connect to internet by applying the following command in shell

wvdial cdma

Thats it!

List of RSS Feeds I read almost everyday

July 12, 2007 ·

I am sharing a list of RSS feeds that I read almost everyday. And which one is my favorites RSS reader? Well, I use GoogleReader because of it’s excellent features like star and feed history. also I like it’s feed sharing feature.

Damn, why the hell skype is blocking port 80?

June 28, 2007 ·

I was suffering for a ridiculous problem for last couple of days. Something strange (UFO??) was listening at port 8 of my local pc and I couldn’t run apache on port 80. So I was searching for the solution and suddenly found that Matt from wordpress suffered from exactly the same problem. its ridiculous and very annoying!

So I followed the steps Matt suggested in his blog post – I applied the following command at shell

netstat -a -o -n

Then I found that a process with PID 2160 is listening at port 80. I give the following command

tasklist /FI “PID eq 2160”

then I found that the criminal is skype!!! God knows why the hell skype requires to listen at port 80. Then I quit from skype and everything runs fine. After running apache, I restarted skype and it runs smoothly!

WordPress Bangla Date Plugin

June 16, 2007 ·

Yesterday I developed a plug in for wordpress users. Using this plug in you can display all the dates for your posts and comments in Bengali. So download the plug in from the following link, place it in plugins folder and enable it from “plugins” menu in wordpress administration panel. You are done.

I have released under Ekushey. Thanks to Omi Azad for the work.
http://www.ekushey.org/?page/Bangla_Date_Plugin_for_Wordpress

The project was inspired by Humayun bhai from e-Kobi

Using ActiveRecord Library Separately from CodeIgniter

June 13, 2007 ·

CodeIgniters ActiveRecord library is a nice implementation (though modified) of ActiveRecord design pattern. It comes bundled with CodeIgniter. So if you want to use Just this library in your application individually instead of using full CodeIgniter framework, what to do?

Today I’ve spent some time and separate the ActiveRecord library from CodeIgniter. Now you can use it via a class named ActiveRecordFactory. Here’s how to do it (I separate only the MySQL driver) .

I separate the “database” folder under the “system” directory of CodeIgniter. Then I removed all folders in database/drivers except “mysql”. (I need only MySQL, :D)

I modified the class definition at database/drivers/mysql_driver.php
Previously It Was : class CI_DB_mysql_driver extends CI_DB {
Now : class CI_DB_mysql_driver {

I modified the class definition at database/DB_driver.php
Previously It Was : class CI_DB_driver {
Now : class CI_DB_driver extends CI_DB_mysql_driver {

And finally I create a ActiveRecord Factory to instantiate codeigniters Active Record Properly. Here is the code

File: database/ActiveRecordFactory.php

<? /** * This is a Factory to create an instance of Code Igniters Active Record Class * * @author Hasin [http://hasin.wordpress.com] */


define(BASEPATH,"./");
include_once ("drivers/mysql/mysql_driver.php");
include_once ("DB_driver.php");
include_once ("DB_active_rec.php");
include_once ("DB_result.php");
include_once ("drivers/mysql/mysql_result.php");
function log_message(){/*just suppress logging*/}

Class ActiveRecordFactory { private static $dsn; private static $CIAR; public static function Factory($dsn=null) { if (!empty($dsn)) self::$dsn = $dsn; if (empty(self::$CIAR)) { if (!empty(self::$dsn)) self::$CIAR = new CI_DB_active_record($dsn) ; else throw new Exception("Please give a DSN in this format 'driver://username:password@hostname/database'"); } return self::$CIAR; } } ?>

Now You can test The ActiveRecord library like this

<?
include(“database/ActiveRecordFactory.php”);
$activerecord = ActiveRecordFactory::Factory(“mysql://user:password@localhost/test”);
$activerecord = ActiveRecordFactory::Factory();

$activerecord->select(“name”);
$activerecord->where(“id=”,”10″);
$activerecord->orwhere(“id=”,”19″);
print_r($activerecord->get(“users”)->result_array());

$activerecord->select(“name”);
$activerecord->where(“id=”,”10″);
$activerecord->orwhere(“id=”,”19″);
echo $activerecord->get(“users”)->num_rows();

$activerecord->insert(“users”,array(“name”=>”CodeIgniter”,”pass”=>”CI Rocks”));
?>

You can download the complete example from here http://hasin.javapark.net/ActiveRecord.zip

The Storyteller

Rise Of The Machines