sharath: 2012

Friday, December 14, 2012

Finding geo location of the ip address in PHP

If you are using google map in your application and wanted to show the user location google map in your application. then we the find the ip address and get the geo location of the ip address. Bellow is the method to find the city by passing the ip address Using PHP.

/**
* Funtion to find the city by passing the IP Address.
*/
function geoCheckIP($ip)
{

//check, if the provided ip is valid

if (!filter_var($ip, FILTER_VALIDATE_IP))
{

throw new InvalidArgumentException("IP is not valid");
}

//contact ip-server

$response = @file_get_contents('http://www.netip.de/search?query=' . $ip);

if (empty($response))
{

throw new InvalidArgumentException("Error contacting Geo-IP-Server");
}

//Array containing all regex-patterns necessary to extract ip-geoinfo from page

$patterns = array();

$patterns["town"] = '#City: (.*?)<br#i';

//Array where results will be stored

$ipInfo = array();

//check response from ipserver for above patterns

foreach ($patterns as $key => $pattern)
{

//store the result in array

$ipInfo[$key] = preg_match($pattern, $response, $value) && !empty($value[1]) ? $value[1] : 'not found';
}
/* I've included the substr function for Country to exclude the abbreviation (UK, US, etc..)
To use the country abbreviation, simply modify the substr statement to:
substr($ipInfo["country"], 0, 3)
*/
$ipdata = $ipInfo["town"];

return $ipdata;
}

geoCheckIP('50.56.112.226');

For more dinformation and send me comments.

Getting Client IP using PHP

To track the client location we need the ip address of the user machine/ mobile device. As PHP is a Server side script we can easilly track the user/client ip address using the bellow php function.

function getRealIpAddr()
{
if (!empty($_SERVER['HTTP_CLIENT_IP']))
//check ip from share internet
{
$ip = $_SERVER['HTTP_CLIENT_IP'];
}
elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR']))
//to check ip is pass from proxy
{
$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
}
else
{
$ip = $_SERVER['REMOTE_ADDR'];
}
return $ip;
}

$ip = getRealIpAddr();

For feedback , leave me comments.

Fetching the images based on screen resolution

One of the main issues in the mobile web application is to fetch the images based on the mobile screen resolution . There are different method to fetch the images but im here explain, fetching the image based on the screen resolution. Normally in the android mobile we will calculate the DPI(density per inches) and in the iphone PPI(pixel per inches) . Here im taking the screen resolution.

function getResolution()
{
window.imagePath ='';
//get screen resolution of customer
var custHeight = screen.height;
var custWidth = screen.width;
//if the screed width less then screen height
if( custWidth < custHeight)
{
if (custWidth <= 320)
{
window.imagePath = 'drawable-mdpi';
}
else if (custWidth <= 480)
{
window.imagePath = 'drawable-hdpi';
}
else
{
window.imagePath = 'drawable-xhdpi';
}
}
else
{
//else if the screed width greater then screen height
if (custWidth <= 480)
{
window.imagePath = 'drawable-mdpi';
}
else if (custWidth <= 600)
{
window.imagePath = 'drawable-hdpi';
}
else
{
window.imagePath = 'drawable-xhdpi';
}
}
}

Just call the getResolution() method when the page first loads. then use the window.imagePath anywhere in your application. window.imagePath is the global varible here.

This post will really help you. For feed back leave me comments.

Hidding the Address Bar in Mobile Browser

All Mobile web application need address bar hiding option, becuase basically mobile screens are very small in size compared to the Desktop.

Use bellow to code to hide the address. It may help you to solve the other sort of challenges.

function hideAddressBar()
{
if(!window.location.hash)
{
if(document.height < window.outerHeight)
{
document.body.style.height = (window.outerHeight + 50) + 'px';
}
setTimeout( function(){ window.scrollTo(0, 1); }, 200 );
setInterval("hideAddressBar()", 6000);
}
}

Use the code and call function hideAddressBar(); whenever you required to hide the address bar.

hope, It may help you. If you have any query leave me comments.

Tuesday, April 3, 2012

Simulate submitting a form using cURL

So what is cURL anyway? cURL stands for “Client URL", and it is a library of functions that can be used to connect through a wide range of protocols, such as HTTP, FTP, telnet and so on. cURL also speaks HTTPS, so it can be used to communicate with secure servers.

What we are going to use is, cURL HTTP. cURL supports POST and GET methods, file uploads, cookies, user/password authentications, even using proxy servers for connecting.

It can literally be used to programmatically simulate browsing behavior. It can connect to a remote site, login by posting username and password to the login form or by using HTTP authentication, then retrieve pages or upload files. All of this using pure PHP code.

So how do I use cURL to post data?

Begin by creating a new connection.

  $curl_connection =

  curl_init('http://www.domainname.com/target_url.php');

A new connection is created using curl_init() function, which takes the target URL as parameter (The URL where we want to post our data). The target URL is same as the "action" parameters of a normal form, which would look like this:

<form method="post" action="http://www.domainname.com/target_url.php">

Now let's set some options for our connection. We can do this using the curl_setopt() function. Go to curl_setopt() reference page for more information on curl_setopt() and a complete list of options.

    curl_setopt($curl_connection, CURLOPT_CONNECTTIMEOUT, 30);

    curl_setopt($curl_connection, CURLOPT_USERAGENT,

    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)");

    curl_setopt($curl_connection, CURLOPT_RETURNTRANSFER, true);

    curl_setopt($curl_connection, CURLOPT_SSL_VERIFYPEER, false);

    curl_setopt($curl_connection, CURLOPT_FOLLOWLOCATION, 1);

What options do we set here?

First, we set the connection timeout to 30 seconds, so we don't have our script waiting indefinitely if the remote server fails to respond.

Then we set how cURL will identify itself to the remote server. Some servers will return different content for different browsers (or agents, such as spiders of the search engines), so we want our request to look like it is coming from a popular browser.

CURLOPT_RETURNTRANSFER set to true forces cURL not to display the output of the request, but return it as a string.

Then we set CURLOPT_SSL_VERIFYPEER option to false, so the request will not trigger an error in case of an invalid, expired or not signed SSL certificate.

Finally, we set CURLOPT_FOLLOWLOCATION to 1 to instruct cURL to follow "Location: " redirects found in the headers sent by the remote site.

Now we must prepare the data that we want to post. We can first store this in an array, with the key of an element being the same as the input name of a regular form, and the value being the value that we want to post for that field.

For example,if in a regular form we would have:

<input type="text" name="firstName" value="Name">

<input type="hidden" name="action" value="Register">

we add this to our array like this:

$post_data['firstName'] = 'Name';

$post_data['action'] = 'Register'

Do the same for every form field.

Data will be posted in the following format:

key1=value1&key2=ವಲುಎ೨

In order to format the data like this, we are going to create strings for each key-value pair (for example key1=value1), put them in another array ($post_items) then combine them in one string using PHP function implode() .

foreach ( $post_data as $key => $value)

{

    $post_items[] = $key . '=' . $value;

}

$post_string = implode ('&', $post_items);

Next, we need to tell cURL which string we want to post. For this, we use the CURLOPT_POSTFIELDS option.

curl_setopt($curl_connection, CURLOPT_POSTFIELDS, $post_string);

Finally, we execute the post, then close the connection.

$result = curl_exec($curl_connection);

curl_close($curl_connection);

By now, the data should have been posted to the remote URL. Go check this, and if it did not work properly, use curl_getinfo() function to see any errors that might have occurred.

print_r(curl_getinfo($curl_connection));

This line displays an array of information regarding the transfer. This must be used before closing the connection with curl_close();

You can also see number and description of the error by outputting curl_errno($curl_connection) and curl_error($curl_connection).

So let's put everything together. Here is our code:

<?php

//create array of data to be posted

$post_data['firstName'] = 'Name';

$post_data['action'] = 'Register';

//traverse array and prepare data for posting (key1=value1)

foreach ( $post_data as $key => $value) {

    $post_items[] = $key . '=' . $value;

}

//create the final string to be posted using implode()

$post_string = implode ('&', $post_items);

//create cURL connection

$curl_connection =

  curl_init('http://www.domainname.com/target_url.php');

//set options

curl_setopt($curl_connection, CURLOPT_CONNECTTIMEOUT, 30);

curl_setopt($curl_connection, CURLOPT_USERAGENT,

  "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)");

curl_setopt($curl_connection, CURLOPT_RETURNTRANSFER, true);

curl_setopt($curl_connection, CURLOPT_SSL_VERIFYPEER, false);

curl_setopt($curl_connection, CURLOPT_FOLLOWLOCATION, 1);

//set data to be posted

curl_setopt($curl_connection, CURLOPT_POSTFIELDS, $post_string);

//perform our request

$result = curl_exec($curl_connection);

//show information regarding the request

print_r(curl_getinfo($curl_connection));

echo curl_errno($curl_connection) . '-' .

                curl_error($curl_connection);

//close the connection

curl_close($curl_connection);

?>

Post form data without using cURL

If your hosting server does not come with cURL installed (though this is rare as cURL is installed on most commercial hosting servers) and you also don’t have access to server in order to install it, there are alternatives.

One of them is using PHP’s functions fsockopen() and fputs() to send properly formatted data to a remote server. Here is a sample of code that does just this:

<?php

//create array of data to be posted

$post_data['firstName'] = 'Name';

$post_data['action'] = 'Register';

//traverse array and prepare data for posting (key1=value1)

foreach ( $post_data as $key => $value) {

$post_items[] = $key . '=' . $value;

}

//create the final string to be posted using implode()

$post_string = implode ('&', $post_items);

//we also need to add a question mark at the beginning of the string

$post_string = '?' . $post_string;

//we are going to need the length of the data string

$data_length = strlen($post_string);

//let's open the connection

$connection = fsockopen('www.domainname.com', 80);

//sending the data

fputs($connection, "POST /target_url.php HTTP/1.1\r\n");

fputs($connection, "Host: www.domainname.com \r\n");

fputs($connection,

"Content-Type: application/x-www-form-urlencoded\r\n");

fputs($connection, "Content-Length: $data_length\r\n");

fputs($connection, "Connection: close\r\n\r\n");

fputs($connection, $post_string);

//closing the connection

fclose($connection);

?>