Tuesday, 6 August 2013
Thursday, 25 July 2013
Useful Jquery
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Useful Jquery</title>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script>
var count =0;
$(document).ready(function () {
$("#customButton1").click(function(){
var div_id = "#div_show"+count;
count++;
$(div_id).append("<div id='div_show" + count + "'><input type='text' name='pro_name" + count + "' /> <input type='text' name='qty_name" + count + "' /></div>");
});
$("#customButton2").click(function() {
if(count>0){
var div_id = "#div_show"+count;
count--;
$(div_id).remove();
}
});
});
</script>
</head>
<body>
<div id="div_show0"> </div>
<input type="button" id="customButton1" value="Add product and quantity textbox" />
<input type="button" id="customButton2" value="Remove product and quantity textbox" />
</body>
</html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Useful Jquery</title>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script>
var count =0;
$(document).ready(function () {
$("#customButton1").click(function(){
var div_id = "#div_show"+count;
count++;
$(div_id).append("<div id='div_show" + count + "'><input type='text' name='pro_name" + count + "' /> <input type='text' name='qty_name" + count + "' /></div>");
});
$("#customButton2").click(function() {
if(count>0){
var div_id = "#div_show"+count;
count--;
$(div_id).remove();
}
});
});
</script>
</head>
<body>
<div id="div_show0"> </div>
<input type="button" id="customButton1" value="Add product and quantity textbox" />
<input type="button" id="customButton2" value="Remove product and quantity textbox" />
</body>
</html>
Monday, 8 July 2013
Wednesday, 3 July 2013
Message for everyone
This message is for everyone. If you are working as freelancer or have company, I may help you in promoting your site/blog through google plus/blog. I am promoting my blog at google plus and getting 50-60 page views daily. I will add you at google plus and so automatically your site/blog will be promoted.
Note : This is for no charge. Contact me through chat / email.
Note : This is for no charge. Contact me through chat / email.
Tuesday, 2 July 2013
Thursday, 20 June 2013
PHP 5.5 released now.
PHP 5.5 released now. (20-Jun-2013). For all changes, read the complete changelog.There are no big changes, important changes you can view at, Changes. More coming soon
Tuesday, 18 June 2013
Commercial email ACT
Copied from, http://business.ftc.gov/documents/bus61-can-spam-act-compliance-guide-businessSummary,Use proper header,Your “From,” “To,” “Reply-To,” etc should true not fake.
Subject should not be misleading.- If your email is ad, then clearly disclose that your message is an advertisement
. - Tell recipients where you’re located. This can be your current street address, a post office box you’ve registered with the U.S. Postal Service, or a private mailbox you’ve registered with a commercial mail receiving agency established under Postal Service regulations
- Any opt-out mechanism you offer must be able to process opt-out requests for at least 30 days after you send your message. Give Un-subscrition option and that email should not be block by our own server (like as spam). Also give options to select how to receive future emails. That should be clear (font, color, etc). You must honor a recipient's opt out request within 10 business days
- You can't sell emails to anyone.
Hello jQuery
In jQuery, $ is variable which are chainable, (chainable means we can call multiple methods calls in chain, like,
$("#id").method1('value').method2('value2');
Don't worry, if you don't understand at this time. Later, you will learn it.
$("*") // * means all so it will select all elements of html DOM.
$('table') // to select all tables in html page.
General,
$('elems') // this will select all elements of html page, that are elems.
For more list, please visit http://api.jquery.com/category/selectors/
$("#id").method1('value').method2('value2');
Don't worry, if you don't understand at this time. Later, you will learn it.
- Selecting DOM object through jQuery, (if you don't know DOM, I will post on html DOM some other day, but then only you will understand it)
$("*") // * means all so it will select all elements of html DOM.
$('table') // to select all tables in html page.
General,
$('elems') // this will select all elements of html page, that are elems.
- Selecting all css classes using jQuery,
- $("#id1") // this will select element having idi as id
For more list, please visit http://api.jquery.com/category/selectors/
Monday, 17 June 2013
jQuery basic
Visit official jquery site. jQuery is javascript library which is cross-platform/ browser, fast, robust, easy to learn. It makes things easy which are difficult to do in alone javascript (although, jQuery itself is in javascript). It creates, virtual namespace (which is advance for beginner, so I am not explaining here). Main benefits of jQuery ,
- It makes javascript programming easy.
- Platform independent / Cross- browser
- It's used by millions of people.
- Unobtrusive JavaScript. It seperates html and javascript. (Though, it can't seperates100%, and it also depend on your own coding.
- It is used by wordpress/ wikipedia
- Progressive enhancement - if browser don't support few features of javascript / jQuery, there should be way to access basic content of page. Javascript should provide enhancement/ wow effect. But it doesn't mean, without javascript, we can't access page. Like when you visit, mail.google.com (gmail) and internet is slow, a pop up comes that says, load basic html. It's progressive enhancement.
- Degrading gracefully - if javascript is disabled, page should load properly. Like above gmail example.It is reverse of progressive enhancement.
<script src="http:////ajax.googleapis.com/ajax/libs/jquery/1.10.1/jquery.min.js"></script>Now, you are ready to go, see next blog for learning jQuery
Monday, 13 May 2013
Time out problem solved if using cron job
I was getting timeout while running cron job. That problem is solved by following code. But problem is, it only works properly in cron job. If I open through browser, script will end abruptly. Anyway, we don't have time out problem using browser because we can use ajax.
$end_time = 600;//600 seconds is end time of script.
$pid = pcntl_fork();
if ($pid < 0)
exit;
else if ($pid) // parent
exit;
else {// child
$sid = posix_setsid();
if ($sid < 0){
exit;
}
for($i = 0; (time() - $end_time)<0; $i++) {
usleep($sleep_time);
//do something, it will not time out.
}
}
For details, please visit,
http://php.net/manual/en/function.posix-setsid.php
More coming soon
Friday, 19 April 2013
Output database tables in CSV
For lattest updates please visit, http://web2students.com/web2blog/
Code to output all tables with data in CSV (comma seperated version) without using phpmyadmin.
<?php
define("DB","test_db");
define("LB","\n\r");
define("SEPERATOR","\t");
function init(){
mysql_connect("localhost","root","");
mysql_select_db(DB);
}
function get_tables(){
$query = mysql_query("show tables");
$tables = array();
$col_name = "Tables_in_".DB;
while($result=mysql_fetch_assoc($query)){
$tables[] = $result[$col_name];
}
return ($tables);
}
init();
function table_header($table){
$out = "";
$result = mysql_query("SHOW COLUMNS FROM $table");
while($header = mysql_fetch_assoc($result)){
$out .= $header['Field'].SEPERATOR;
}
$out = substr($out,0,strlen($out)-1);//remove last comma
return($out);
}
function table_content($table){
$out = "";
$query = mysql_query("select * from $table");
while($result=mysql_fetch_assoc($query)){
$row = "";
foreach($result as $column){
$row .= $column.SEPERATOR;
}
$row .= substr($out,0,strlen($row)-1);//remove last comma
$out .= $row.LB;
}
return($out);
}
$out = "";
$tables = get_tables();
foreach($tables as $table){
$out .= "Data in table $table".LB;
$out .= table_header($table);
$out .= LB;
$out .= table_content($table);
$out .= LB;
}
header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=output.xls");
header("Pragma: no-cache");
header("Expires: 0");
echo $out;
?>
Code to output all tables with data in CSV (comma seperated version) without using phpmyadmin.
<?php
define("DB","test_db");
define("LB","\n\r");
define("SEPERATOR","\t");
function init(){
mysql_connect("localhost","root","");
mysql_select_db(DB);
}
function get_tables(){
$query = mysql_query("show tables");
$tables = array();
$col_name = "Tables_in_".DB;
while($result=mysql_fetch_assoc($query)){
$tables[] = $result[$col_name];
}
return ($tables);
}
init();
function table_header($table){
$out = "";
$result = mysql_query("SHOW COLUMNS FROM $table");
while($header = mysql_fetch_assoc($result)){
$out .= $header['Field'].SEPERATOR;
}
$out = substr($out,0,strlen($out)-1);//remove last comma
return($out);
}
function table_content($table){
$out = "";
$query = mysql_query("select * from $table");
while($result=mysql_fetch_assoc($query)){
$row = "";
foreach($result as $column){
$row .= $column.SEPERATOR;
}
$row .= substr($out,0,strlen($row)-1);//remove last comma
$out .= $row.LB;
}
return($out);
}
$out = "";
$tables = get_tables();
foreach($tables as $table){
$out .= "Data in table $table".LB;
$out .= table_header($table);
$out .= LB;
$out .= table_content($table);
$out .= LB;
}
header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=output.xls");
header("Pragma: no-cache");
header("Expires: 0");
echo $out;
?>
Wednesday, 17 April 2013
Learn .htaccess (URL-re-write)
For lattest updates please visit, http://web2students.com/web2blog/
.htaccess (hypertext access) file has only extension no name. So,if you can't create on windows, just download from internet and edit it. As there is no file name, it's sometimes invisible. So, on server, first change settings to view hidden files (if you have permission and ftp/ cpanel has this feature). It's directory-level configuration file supported by several web servers. Directory-level configuration means, it will effect files that are in that directory or in sub-directory, it can't effect outside that directory.
What we can do with .htaccess?
# this is comment
404 error- Following file will be loaded when 404 error will occur,
Above line says to redirect from /folder/oldfile.html to /newpage.html . [L,R=301] , This means, if this match is found, it's last command. Server don't try to match rest of .htaccess file. And R=301 means to re-direct and sending 301 headers. There are 2 types of headers for re-direct. 301 and 302. 301 is used for,Moved Permanently response and 302 is used for Moved temprory response. Why we care about these headers?It's used by search engine. If document is moved permanent , search engine will update the url in it's database. Else, it will not update.
You need to read all with example to understand below,
RewriteCond %{REQUEST_FILENAME} !-f
Explanation - Above line has 2 parts. First, RewriteCond (re-write condition)- this is re-write continue directives. It tells if condition is met, then continue re-writing. Condition is %{REQUEST_FILENAME} !-f. it says, if requested file is not found !-f means if file is not found then apply re-write rule (that rule will be written below that)
RewriteCond %{REQUEST_FILENAME} !-d
Above tells, if directory is not found then continue re-writing.
Now, if you want to re-write like,
.htaccess (hypertext access) file has only extension no name. So,if you can't create on windows, just download from internet and edit it. As there is no file name, it's sometimes invisible. So, on server, first change settings to view hidden files (if you have permission and ftp/ cpanel has this feature). It's directory-level configuration file supported by several web servers. Directory-level configuration means, it will effect files that are in that directory or in sub-directory, it can't effect outside that directory.
What we can do with .htaccess?
- URL- rewrite - (like user visits, http://web2students.blogspot.in/file1.html but really access, public_html/file2.html ). It is used for SEO purpose.
- Error document (404 page) - we can re-direct to customized page when user visits, non existing page.
- Blocking user by IP address.
- Many more things.
# this is comment
404 error- Following file will be loaded when 404 error will occur,
ErrorDocument 404 /error_handler.html
We can also handle other errors, ( 400, 401, 500, etc).
Blocking IP address,
order allow,deny
deny from 11.11.1.1
deny from 22.22.2.2
allow from all
Explanation -
allow and deny are directives. Directives means one line command. First we write that following section defines allowing or denying access to server by using line,
order allow,deny
then we write deny from ip address (it's used to deny access to that ip address).
Last line used to allow all other.
Redirecting to other page,
redirect /folder/oldfile.html /newpage.html [L,R=301]Above line says to redirect from /folder/oldfile.html to /newpage.html . [L,R=301] , This means, if this match is found, it's last command. Server don't try to match rest of .htaccess file. And R=301 means to re-direct and sending 301 headers. There are 2 types of headers for re-direct. 301 and 302. 301 is used for,Moved Permanently response and 302 is used for Moved temprory response. Why we care about these headers?It's used by search engine. If document is moved permanent , search engine will update the url in it's database. Else, it will not update.
You need to read all with example to understand below,
RewriteCond %{REQUEST_FILENAME} !-f
Explanation - Above line has 2 parts. First, RewriteCond (re-write condition)- this is re-write continue directives. It tells if condition is met, then continue re-writing. Condition is %{REQUEST_FILENAME} !-f. it says, if requested file is not found !-f means if file is not found then apply re-write rule (that rule will be written below that)
RewriteCond %{REQUEST_FILENAME} !-d
Above tells, if directory is not found then continue re-writing.
Now, if you want to re-write like,
http://shoppingsite/product.php?product_id=1 to http://shoppingsite/products/productnameYou will get productname from database. There is 1 to 1 relation of product_id and productname. Else it will not run. Why change to such URL?First it's good to have url having name of product not id. Second, good for SEO. Third, easy to remember. More coming soon. Also read this, http://www.addedbytes.com/articles/for-beginners/url-rewriting-for-beginners/Thursday, 11 April 2013
Introduction to HTML5
Features of HTML5,
Lots talk about theory, now time to getting started.
Doctype,
<!DOCTYPE html>
Enconding (required for security reasons),
<meta charset="utf-8"> (charset=utf-8 , charset='utf-8' , charset="utf-8" all are allowed, follow whatever you prefer, you can write like older long way).
Sample HTML5 page,
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Web2 Students blog</title>
</head>
<body>
<p>Introduction to html5</p>
</body>
</html>
Adding external CSS and JS,
<link rel="stylesheet" href="styles.css" />
<script src="scripts.js"></script>
<article> - It is self-contained content. It can be like div but with special semantic. Like articles can be list of posts in blog, news items, forum posts, comments on posts, etc. So, individual article is like single entry of list of items. It can contain <h1> , <p>, (like div )etc.
<header> - it's in header of html page. Normally, it contains, title, logo, link to home page, and other links, etc. It can be in the article containing heading of the article.
<hgroup> - It used to group heading (h1-h6) elements. It is used inside header.
<nav> - It's used for navigation links.
<footer> - As the name suggest, it's used as footer. Like header, it can be used in multiple times (in section). While multiple times, header and footer will be header and footer part of that section (like, in article). Example,
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Web2 Students blog</title>
</head>
<body>
</html>
More coming soon.
- There are many new elements like <article> , <canvas> , <footer> , <header> , <section> , <hgroup> , <nav> , <audio> , <video> , <datalist> , etc
- Removed elements,<acronym> , <applet> , <basefont> , <big> , <center>, <frame>, etc
- Added New Attributes even we can add custom attributes. Custom attributes starts with data- string like ,
<div data-customfield="value" data-language="html"> .... </div>
- Full CSS3 Support
- 2D/3D Graphics
- Local Storage
- Local SQL Database (we can run sql query in browser but that is no longer active.
- HTML5 is simplified.HTML5 is much more Semantic than html4.
- Many more...
Lots talk about theory, now time to getting started.
Doctype,
<!DOCTYPE html>
Enconding (required for security reasons),
<meta charset="utf-8"> (charset=utf-8 , charset='utf-8' , charset="utf-8" all are allowed, follow whatever you prefer, you can write like older long way).
Sample HTML5 page,
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Web2 Students blog</title>
</head>
<body>
<p>Introduction to html5</p>
</body>
</html>
Adding external CSS and JS,
<link rel="stylesheet" href="styles.css" />
<script src="scripts.js"></script>
<article> - It is self-contained content. It can be like div but with special semantic. Like articles can be list of posts in blog, news items, forum posts, comments on posts, etc. So, individual article is like single entry of list of items. It can contain <h1> , <p>, (like div )etc.
<header> - it's in header of html page. Normally, it contains, title, logo, link to home page, and other links, etc. It can be in the article containing heading of the article.
<hgroup> - It used to group heading (h1-h6) elements. It is used inside header.
<nav> - It's used for navigation links.
<footer> - As the name suggest, it's used as footer. Like header, it can be used in multiple times (in section). While multiple times, header and footer will be header and footer part of that section (like, in article). Example,
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Web2 Students blog</title>
</head>
<body>
<nav>
<ul>
<li><a href="index.html">Home</a></li>
<li><a href="/about/">About</a></li>
<li><a href="/blog/">Blog</a></li>
</ul>
</nav>
<article>
<header>
<hgroup>
<h1>Introduction to HTML5</h1>
<h2>Example of HTML5</h2>
</hgroup>
</header>
<footer>
<p>Published: <time datetime="2013-04-12T00:00:00-00:00" pubdate>April 12,2013 0:00 am EDT</time></p>
</footer>
</article>
</body></html>
More coming soon.
Wednesday, 10 April 2013
Database Indexes
Mysql database has InnoDB and MyISAM storage engines. Both of them have different features. Differences between are,
- MyISAM tables use table-level locking where as
InnoDBimplements standard row-level locking , which means InnoDB is better. A lock that prevents any other transaction from accessing a table. So, during select or insert query in MyISAM table, all others transaction on same table will not be executed. So, wastage of resources. But in InnoDB, only that row will be locked. - InnoDB have Clustered index and MyISAM has no clustered index. There are two types of Indexes (Clustered and non-clustered index.) A clustered index is a special type of index that reorders the way records in the table are physically stored. Therefore table can have only one clustered index. The leaf nodes of a clustered index contain the data pages. A nonclustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows on disk. The leaf node of a nonclustered index does not consist of the data pages. Instead, the leaf nodes contain index rows. Example, in book, there is index which tells page number direct to the content.Second way is to write page number of content as well as number of next index, and so on. So, MyISAM is not so efficient in way of time of selection but it saves space and time in insertion in database. As in InnoDB, all indexes are shuffled and re- arranged according to order. It helps in speed up searching. Down-side of InnoDBis, it required more space.
- MyISAM supports full text search but InnoDB don't.
- InnoDB supports Foreign Key and Transaction Model. MyISAM doesn't support transation and doesn't support foreign key natively (what natively means?I will read and tell you later). More next time.
Monday, 8 April 2013
HTML5 exciting things
New exciting things about HTML5 and new technologies are,
The WebSocket protocol was standardized by the IETF as RFC 6455 in 2011, and the WebSocket API for in Web IDL is being standardized by the W3C
Example,
We need to tell whether, connection is over ws or wss (like HTTP or HTTPS). Creating websocket object,
var ws = new WebSocket("ws://www.example.com");
more coming soon.
- WebSocket is a web technology providing full-duplex communications channels over a single TCP connection. HTML is stateless. Really?Read websocket. Prior it was, server will communicate browser, browser will reply, and so on. One at a time. But websocket is two-way communication.
- You can run sql in Web-browser. But it's no longer active, see, http://www.w3.org/TR/webdatabase/
- WebRTC for real time communication (voice, video chat, etc)
- Features like high performance 2D and 3D graphics, offline asset storage, rich audio APIs, and socket-based networking let you create compelling modern games with a reach like never before.
- So on...
The WebSocket protocol was standardized by the IETF as RFC 6455 in 2011, and the WebSocket API for in Web IDL is being standardized by the W3C
Example,
We need to tell whether, connection is over ws or wss (like HTTP or HTTPS). Creating websocket object,
var ws = new WebSocket("ws://www.example.com");
more coming soon.
Code is for posting data to multiple sites using multi curl in php
This code is for posting data to multiple sites using multi curl in php. Useful for looping and posting to multiple site.
<?php
class curl_post{
function __construct(){
$this->curl_urls = array();
$this->ch = array();
$this->num_url = 0;
$this->output = array();
$this->multi_curl = curl_multi_init();
$this->basic_options = array(
//CURLOPT_HEADER => true,
CURLOPT_RETURNTRANSFER => 1,
//CURLOPT_VERBOSE => 1,
CURLOPT_USERAGENT => $_SERVER['HTTP_USER_AGENT'],
CURLOPT_SSL_VERIFYPEER => false
);
}
function add_url($options){
++$this->num_url;
$this->ch[$this->num_url] = curl_init();
foreach($this->basic_options as $k => $v){
$options[$k] = $v;
}
curl_setopt_array($this->ch[$this->num_url], $options);
curl_multi_add_handle($this->multi_curl,$this->ch[$this->num_url]);
}
function exe_curl(){
$active = null;
do {
curl_multi_exec($this->multi_curl,$active);
} while($active > 0);
foreach($this->ch as $ch){
$this->output[] = curl_multi_getcontent($ch);
}
}
function __destruct(){
foreach($this->ch as $ch){
curl_multi_remove_handle($this->multi_curl, $ch);
curl_close($ch);
}
curl_multi_close($this->multi_curl);
}
}
Example
/*$curl_obj = new curl_post();
$data = "var1=value1&postvar2=value2&postvar3=value3";
$options = array(CURLOPT_URL => 'url-location1', CURLOPT_POSTFIELDS => $data);
$curl_obj->add_url($options);
$options = array(CURLOPT_URL => 'url-location2', CURLOPT_POSTFIELDS => "testing=value&test2=value2");
$curl_obj->add_url($options);
$options = array(CURLOPT_URL => '');
$curl_obj->add_url($options);
$curl_obj->exe_curl();
print_r($curl_obj->output);*/
<?php
class curl_post{
function __construct(){
$this->curl_urls = array();
$this->ch = array();
$this->num_url = 0;
$this->output = array();
$this->multi_curl = curl_multi_init();
$this->basic_options = array(
//CURLOPT_HEADER => true,
CURLOPT_RETURNTRANSFER => 1,
//CURLOPT_VERBOSE => 1,
CURLOPT_USERAGENT => $_SERVER['HTTP_USER_AGENT'],
CURLOPT_SSL_VERIFYPEER => false
);
}
function add_url($options){
++$this->num_url;
$this->ch[$this->num_url] = curl_init();
foreach($this->basic_options as $k => $v){
$options[$k] = $v;
}
curl_setopt_array($this->ch[$this->num_url], $options);
curl_multi_add_handle($this->multi_curl,$this->ch[$this->num_url]);
}
function exe_curl(){
$active = null;
do {
curl_multi_exec($this->multi_curl,$active);
} while($active > 0);
foreach($this->ch as $ch){
$this->output[] = curl_multi_getcontent($ch);
}
}
function __destruct(){
foreach($this->ch as $ch){
curl_multi_remove_handle($this->multi_curl, $ch);
curl_close($ch);
}
curl_multi_close($this->multi_curl);
}
}
Example
/*$curl_obj = new curl_post();
$data = "var1=value1&postvar2=value2&postvar3=value3";
$options = array(CURLOPT_URL => 'url-location1', CURLOPT_POSTFIELDS => $data);
$curl_obj->add_url($options);
$options = array(CURLOPT_URL => 'url-location2', CURLOPT_POSTFIELDS => "testing=value&test2=value2");
$curl_obj->add_url($options);
$options = array(CURLOPT_URL => '');
$curl_obj->add_url($options);
$curl_obj->exe_curl();
print_r($curl_obj->output);*/
Friday, 5 April 2013
XUL Mozilla firefox programming
Mozilla Firefox is a free and open source web browser developed for Windows, OS X, Linux, and Android by Mozilla Foundation and its subsidiary, the Mozilla Corporation. Firefox uses the Gecko layout engine to render web pages, which implements current and anticipated web standards. Copied from wikipedia
Have you worked with FireBug and other application that works over firefox. XUL (XML User Interface Language) is Mozilla's XML-based language for building user interfaces. Official site can be found at, https://developer.mozilla.org/en/docs/XUL
See this, http://getfirebug.com/ Firebug and other firefox's extension are developed in XUL language.
Firefox extensions are applications that add new functionality to Mozilla applications such as Firefox and Thunderbird. It is also worth noting that there are differences between the definition of extension and add-on. All extensions are add-ons, but add-ons can also be themes, plugins, or language packs. XUL uses, mixture of XML, HTML, JS, CSS, Resource Description Framework (RDF), etc. So, if you are web-designer/developer you will feel at home. More coming soon.
XUL (pronounced "zool") is one of many technologies used for creating Mozilla-based products and extensions. It is only one part of the development landscape, but given that it's practically exclusive to Mozilla, it tends to be used to identify all Mozilla-related development. Copied from https://developer.mozilla.org/en-US/docs/XUL/School_tutorial/Introduction (also official site of firefox for learning XUL). More coming soon.
Have you worked with FireBug and other application that works over firefox. XUL (XML User Interface Language) is Mozilla's XML-based language for building user interfaces. Official site can be found at, https://developer.mozilla.org/en/docs/XUL
Firefox extensions are applications that add new functionality to Mozilla applications such as Firefox and Thunderbird. It is also worth noting that there are differences between the definition of extension and add-on. All extensions are add-ons, but add-ons can also be themes, plugins, or language packs. XUL uses, mixture of XML, HTML, JS, CSS, Resource Description Framework (RDF), etc. So, if you are web-designer/developer you will feel at home. More coming soon.
XUL (pronounced "zool") is one of many technologies used for creating Mozilla-based products and extensions. It is only one part of the development landscape, but given that it's practically exclusive to Mozilla, it tends to be used to identify all Mozilla-related development. Copied from https://developer.mozilla.org/en-US/docs/XUL/School_tutorial/Introduction (also official site of firefox for learning XUL). More coming soon.
Thursday, 4 April 2013
Connecting to multiple databases without disconnecting to prior connected databases
Below is code to connect with multiple databases without disconnecting to prior connected databases. It needed some improvement, but I will do some other day.
class db_class{
private static $db_link = array();
private function __construct(){
//creating object is not allowed
}
static function getConnect($type,$db_detail_array=""){
if(empty(self::$db_link[$type])){
self::$db_link[$type] = mysql_connect($db_detail_array['host_name'],$db_detail_array['user'],$db_detail_array['pass']);
mysql_select_db($db_detail_array['db']);
}
}
static function run_query($query,$type){
self::getConnect($type);
$db_query = mysql_query($query,self::$db_link[$type]);
return($db_query) ;
}
static function fetch_array($query,$type){
$db_query = self::run_query($query,$type);
$results = array();
while($fetch_arr=mysql_fetch_assoc($db_query)){
$results[] = $fetch_arr;
}
return($results);
}
static function num_rows($query,$type){
$db_query = self::run_query($query,$type);
$num_rows = mysql_num_rows($db_query);
return($num_rows);
}
static function disconnect($type){
mysql_close(self::$db_link[$type]);
}
}
Usage-
$db_detail_array['host_name'] = "host1";
$db_detail_array['user'] = "user1";
$db_detail_array['pass'] = "pass1";
$db_detail_array['db'] = "database1";
$i = 1;
$type1 = "connection".$i;//connection1
db_class::getConnect($type,$db_detail_array);
$query = "SELECT * FROM `table1`";
$db_arr1 = db_class::fetch_array($query,$type);
print_r($db_arr1);
$db_detail_array['host_name'] = "host2";
$db_detail_array['user'] = "user2";
$db_detail_array['pass'] = "pass2";
$db_detail_array['db'] = "database2";
$i = 2;
$type2 = "connection".$i;//connection2
db_class::getConnect($type,$db_detail_array);
$query = "SELECT * FROM `table2`";
$db_arr2 = db_class::fetch_array($query,$type);
print_r($db_arr2);
//back to first database,
$type = "connection1";//connection1 is same as above so no need to connect db_class::getConnect
$query = "select something from table";
$db_arr2 = db_class::fetch_array($query,$type);//directly run query.
You can connect to any database, switch back to previous database with connecting again and so on. And at end of script end all connections to save memory by,
db_class::disconnect($type1);
db_class::disconnect($type2);
That's all for now. More coming soon.
class db_class{
private static $db_link = array();
private function __construct(){
//creating object is not allowed
}
static function getConnect($type,$db_detail_array=""){
if(empty(self::$db_link[$type])){
self::$db_link[$type] = mysql_connect($db_detail_array['host_name'],$db_detail_array['user'],$db_detail_array['pass']);
mysql_select_db($db_detail_array['db']);
}
}
static function run_query($query,$type){
self::getConnect($type);
$db_query = mysql_query($query,self::$db_link[$type]);
return($db_query) ;
}
static function fetch_array($query,$type){
$db_query = self::run_query($query,$type);
$results = array();
while($fetch_arr=mysql_fetch_assoc($db_query)){
$results[] = $fetch_arr;
}
return($results);
}
static function num_rows($query,$type){
$db_query = self::run_query($query,$type);
$num_rows = mysql_num_rows($db_query);
return($num_rows);
}
static function disconnect($type){
mysql_close(self::$db_link[$type]);
}
}
Usage-
$db_detail_array['host_name'] = "host1";
$db_detail_array['user'] = "user1";
$db_detail_array['pass'] = "pass1";
$db_detail_array['db'] = "database1";
$i = 1;
$type1 = "connection".$i;//connection1
db_class::getConnect($type,$db_detail_array);
$query = "SELECT * FROM `table1`";
$db_arr1 = db_class::fetch_array($query,$type);
print_r($db_arr1);
$db_detail_array['host_name'] = "host2";
$db_detail_array['user'] = "user2";
$db_detail_array['pass'] = "pass2";
$db_detail_array['db'] = "database2";
$i = 2;
$type2 = "connection".$i;//connection2
db_class::getConnect($type,$db_detail_array);
$query = "SELECT * FROM `table2`";
$db_arr2 = db_class::fetch_array($query,$type);
print_r($db_arr2);
//back to first database,
$type = "connection1";//connection1 is same as above so no need to connect db_class::getConnect
$query = "select something from table";
$db_arr2 = db_class::fetch_array($query,$type);//directly run query.
You can connect to any database, switch back to previous database with connecting again and so on. And at end of script end all connections to save memory by,
db_class::disconnect($type1);
db_class::disconnect($type2);
That's all for now. More coming soon.
Monday, 1 April 2013
MySql_* extension is deprecated.
Learn MySQLi or PDO_MySQL
1. Why learn?
- MySql_* extension is deprecated as of PHP 5.5.0, and will be removed in the future.
- MySQLi or PDO_MySQL are better than MySql. You will agree with me, when you learn anyone of these.
- If you like OO (object-oriented), then you will like these more.
- Full form of MySqLi is MySqLi (improved) .MySql Improved Extension
MySqLi has dual interface. Procedural and object-oriented interface. You can choose whatever you like. Exactly same functionality is provided in both interfaces but in different ways.
Procedural way example-
<?php//New way $mysqli = mysqli_connect($host, $user, $pass, $database); $res = mysqli_query($mysqli, "SELECT 'something' FROM table"); $row = mysqli_fetch_assoc($res);
echo $row['something'];//Old way $mysql = mysql_connect($host, $user, $pass); mysql_select_db($database);$res = mysql_query("SELECT 'something' FROM table", $mysql); $row = mysql_fetch_assoc($res);
echo $row['something?>
mysqli_connect in which we have to write database name also. So, we don't need mysql_select_db($database); statement line.Object oriented way,$mysqli = new mysqli($host,$user,$pass,$database);
if ($mysqli->connect_errno) {
echo "Failed to connect to MySQL: " . $mysqli->connect_error;
} $res = $mysqli->query("SELECT 'something' FROM table"); $row = $res->fetch_assoc();
echo $row['something'];We can even mix both but it's bad way so I am not going to tell that way.Full list of MySqli function/class can be found at,http://www.php.net/manual/en/mysqli.summary.phpPrepared Statements
A prepared statement
or a parameterized statement is used to execute the same statement
repeatedly with high efficiency.
This is two step process,
First step,
<?php
$mysqli = new mysqli(......);
/* Prepared statement, stage 1: prepare */ if (!($stmt = $mysqli->prepare("INSERT INTO table(column) VALUES (?)"))) {
//Prepare failed
}//use ?,? for multiple ?>Second Step, binding and execution, (? is replaced with real values)
Example #2 Second stage: bind and execute
<?php /* Prepared statement, stage 2: bind and execute */
if (!$stmt->bind_param("column", 'value')) {
//error happens
}
if (!$stmt->execute()) {
//execution error.
}?>Official docs for prepare can be found at, More coming soon.Tuesday, 26 March 2013
Introduction to web-services
Web-service- A web service is a method of communication between two electronic devices over the WWW. So, in web service there are two devices, namely,
- Server - Which has resource and shares it to the client.
- Client - Requests the desired resource from server.
Server provides web API (application programming interface) that is typically a defined set of HTTP request messages along with a definition of the structure of response messages, typically expressed in JSON or XML.
Example of web-services,
Example of web-services,
- Google Map.
- Blogger - Client can create, edit, view, delete and search blog's content using Blogger Data API.
- Amazon
- So on...
So, requirements for web-services,
- The Web services architecture is an interoperability (The ability of software and hardware on different machines from different vendors to share data is interoperability) architecture : because client can be any device. Server must provide resource that is understood by client. So, mostly XML (most of languages including PHP, Java, DotNet, etc can create/ read xml files), JSON (JavaScript on Notation) etc are used.
- Server which gives resource
- Client which requests resource
- Communication to others (to application developer at client side) to use web-services. So, mostly documentation is provided by web-servers.
Web-services-JSON
The two types of web-services are,
Above entity contains details of Customer. As you can see, it stores Customer's FullName and Email. (Note: JSON is case-sensitive so email is different than Email or eMail ) If you know JavaScript multidimensional literal array, JSON will be easy for you (you can google it and learn javascript's array).
If we got above output, how do we access any particular value, say first Customer ' s Email,
var customer1Email = Customer[0].Email;//email@example.com
Similarly, we can access other values in javascript.
PHP functions for JSON,
- REST (Representational State Transfer) which is mostly based on JSON.
- SOAP (Simple Object Access Protocol) which is mostly based on WSDL (web-site description language)
JSON
JavaScript Object Notation is a lightweight data-interchange format. So, it's faster than SOAP (XML format). And hence, application runs faster using same web-service using JSON than XML. Example of JSON ,
{
"Customer": [
{ "FullName":"Some name" , "Email":"email@example.com" },
{ "FullName":"Other name" , "Email":"other@example.com" }
]
}
"Customer": [
{ "FullName":"Some name" , "Email":"email@example.com" },
{ "FullName":"Other name" , "Email":"other@example.com" }
]
}
Above entity contains details of Customer. As you can see, it stores Customer's FullName and Email. (Note: JSON is case-sensitive so email is different than Email or eMail ) If you know JavaScript multidimensional literal array, JSON will be easy for you (you can google it and learn javascript's array).
If we got above output, how do we access any particular value, say first Customer ' s Email,
var customer1Email = Customer[0].Email;//email@example.com
Similarly, we can access other values in javascript.
PHP functions for JSON,
- json_encode http://www.php.net/manual/en/function.json-encode.php (for encoding)
- json_decode http://www.php.net/manual/en/function.json-decode.php (for decoding)
Monday, 11 March 2013
XML (Extensible Markup Language) tutorial
It required to know xml for using SOAP.
Background of XML, html.
Both are markup language. Markup language have markup tags. Tags are special meaning. Suppose, you are reading following line,I am learning XML. XML is easy language.
You paused at full stop (.), you don't spell out (full stop literally), you followed it's meaning not literal meaning. Full stop is like tag. They are commands not just strings like others. All tags are start with < and ends with > . Most tags are in pairs, (opening and closing tags). Other are called empty tags. Some tags have attributes. They are properties of tags. Like <img src="location"> here src is attributes. (In XML tags may have attributes like HTML).
XML is similar to html with few differences given below-
- XML must be well-formed. Even if you skip html closing tag, you will see output correctly in browser. But XML need to be well formed. Well formed XML have following requirements,
- There should be 1 and only 1 document root.
<?xml version="1.0" encoding="UTF-8"?>
<root>
<child>Some text</child>
<child2>More text</child2>
</root>
<root>
<child>Some text</child>
<child2>More text</child2>
</root>
<child2>Some text</child2>
</root2>
It should be changed to,
<?xml version="1.0" encoding="UTF-8"?>
<uniqueRoot>
<root>
<child>Some text</child>
<child2>More text</child2>
</root>
<root>
<child>Some text</child>
<child2>More text</child2>
</root>
<child2>Some text</child2>
</root2>
</uniqueRoot>
- Proper nesting. Parent tag must end after child tag. The relation should be followed,
<parentTag>
<childTag>
Some sring
</parentTag>
</childTag>
Correct format,
<parentTag>
<childTag>
Some sring
</childTag>
</parentTag>
- Every tag must end even empty tag, example,
- Capital and small letter matters (not in html). <TagName> is different tag than <Tagname>.
- HTML has limited pre-defined tags. XML has unlimited tags. You can create tags of your own choice. As there is no pre-defined tags, sometimes DTD is given with XML. DTD (Document Type Definition) to define structure of XML document.
- In XML, special characters must be encoded. It should be encoded in html too , but browsers are intelligent and it don't show errors in HTML. Like if you use & , < , > , etc. But in XML, it will show you errors.
Valid XML
- Valid XML is well formed. (It should follow above all rules).
- It should be according to DTD.
Wednesday, 27 February 2013
Web-services-SOAP
SOAP uses WSDL (which is xml format). More coming soon. Until than read below link
http://www.ibm.com/developerworks/library/ws-soap/?dwzone=ws
http://www.ibm.com/developerworks/library/ws-soap/?dwzone=ws
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