Thursday, August 23, 2012

Explain about Abstraction?


Posted by at No comments:

Polymorphism in OOP:

Polymorphism in OOP:


In this tutorial we will study about polymorphism.
  • Polymorphism in PHP5 : To allow a class member to perform diffrent tasks.
  • polymorphism where the function to be called is detected based on the class object calling it at runtime.

Example:
< ?
class Person
{
    public function Talk()
    {
         echo "English";
    }
}

class Language extends Person
{
      public function Talk()
      {
           echo "French";
      }


}

function CallMethod(Person $p)
{
      $p->Talk();
}



$l = new Language();
CallMethod($l);
?>


Output:
French;

Posted by at No comments:

Tuesday, July 31, 2012

GMT to IST conversion

GMT

 IST (GMT+5.5)
00:00 (midnight) 05:30 (5.30am)
00:30 (12.30am) 06:00 (6am)
01:00 (1am) 06:30 (6.30am)
01:30 (1.30am) 07:00 (7am)
02:00 (2am) 07:30 (7.30am)
02:30 (2.30am) 08:00 (8am)
03:00 (3am) 08:30 (8.30am)
03:30 (3.30am) 09:00 (9am)
04:00 (4am) 09:30 (9.30am)
04:30 (4.30am) 10:00 (10am)
05:00 (5am) 10:30 (10.30am)
05:30 (5.30am) 11:00 (11am)
06:00 (6am) 11:30 (11.30am)
06:30 (6.30am) 12:00 (noon)
07:00 (7am) 12:30 (12.30pm)
07:30 (7.30am) 13:00 (1pm)
08:00 (8am) 13:30 (1.30pm)
08:30 (8.30am) 14:00 (2pm)
09:00 (9am) 14:30 (2.30pm)
09:30 (9.30am) 15:00 (3pm)
10:00 (10am) 15:30 (3.30pm)
10:30 (10.30am) 16:00 (4pm)
11:00 (11am) 16:30 (4.30pm)
11:30 (11.30am) 17:00 (5pm)
12:00 (noon) 17:30 (5.30pm)
12:30 (12.30pm) 18:00 (6pm)
13:00 (1pm) 18:30 (6.30pm)
13:30 (1.30pm) 19:00 (7pm)
14:00 (2pm) 19:30 (7.30pm)
14:30 (2.30pm) 20:00 (8pm)
15:00 (3pm) 20:30 (8.30pm)
15:30 (3.30pm) 21:00 (9pm)
16:00 (4pm) 21:30 (9.30 pm)
16:30 (4.30pm) 22:00 (10pm)
17:00 (5pm) 22:30 (10.30pm)
17:30 (5.30pm) 23:00 (11pm)
18:00 (6pm) 23:30 (11.30pm)
18:30 (6.30pm) 00:00 (midnight)
19:00 (7pm) 00:30 (12.30am)
19:30 (7.30pm) 01:00 (1am)
20:00 (8pm) 01:30 (1.30am)
20:30 8.30pm) 02:00 (2am)
21:00 (9pm) 02:30 (2.30am)
21:30 (9.30pm) 03:00 (3am)
22:00 (10pm) 03:30 (3.30am)
22:30 (10.30pm) 04:00 (4am)
23:00 (11pm) 04:30 (4.30am)
23:30 (11.30pm) 05:00 (5am)
For other conversion refer: http://wwp.greenwichmeantime.com/to/ist/index.htm
Posted by at No comments:

PHP Warning: json_encode() [function.json-encode]: Invalid UTF-8 sequence in argument in

PHP Warning: json_encode() [function.json-encode]: Invalid UTF-8 sequence in argument in The problem we are seeing is that the value being encoded to json is not UTF-8 encoded data. PHP function json_encode, unfortunately, will only accept UTF-8 as its parameter. If you search online, you will find that most people solve this problem by using the PHP function utf8_encode. This is fine and dandy if the data you deal with only contains regular alphanumerical characters (letters and numbers), but what if it contains characters from foreign languages? utf8_encode will most certainly return unwanted values, and this is not what you want. Using utf8_encode is the right idea, but you don’t want to call the function on all your values, just the ones that require it. better to use utf8_encode($value); in the latest php version the warning will not come.
Posted by at No comments:

Monday, January 2, 2012

SOAP

What is SOAP?


SOAP is simple XML based protocol to let applications exchange information over HTTP or SOAP is a protocol for accessing a Web Service.
  • SOAP stands for Simple Object Access Protocol
  • SOAP is a communication protocol
  • SOAP is for communication between applications
  • SOAP is a format for sending messages
  • SOAP communicates via Internet
  • SOAP is platform independent
  • SOAP is language independent
  • SOAP is based on XML
  • SOAP is simple and extensible
  • SOAP allows you to get around firewalls
  • SOAP is a W3C recommendation

Why SOAP?

It is important for application development to allow Internet communication between programs.


SOAP Building Blocks

A SOAP message is an ordinary XML document containing the following elements:
  • An Envelope element that identifies the XML document as a SOAP message
  • A Header element that contains header information
  • A Body element that contains call and response information
  • A Fault element containing errors and status information

Syntax Rules

Here are some important syntax rules:
  • A SOAP message MUST be encoded using XML
  • A SOAP message MUST use the SOAP Envelope namespace
  • A SOAP message MUST use the SOAP Encoding namespace
  • A SOAP message must NOT contain a DTD reference
  • A SOAP message must NOT contain XML Processing Instructions

Skeleton SOAP Message

<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Header>
...
</soap:Header>

<soap:Body>
...
  <soap:Fault>
  ...
  </soap:Fault>
</soap:Body>

</soap:Envelope>

The SOAP Envelope Element

The required SOAP Envelope element is the root element of a SOAP message. This element defines the XML document as a SOAP message.
Example
<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">
  ...
  Message information goes here
  ...
</soap:Envelope>

The xmlns:soap Namespace

Notice the xmlns:soap namespace in the example above. It should always have the value of: "http://www.w3.org/2001/12/soap-envelope".
The namespace defines the Envelope as a SOAP Envelope.
If a different namespace is used, the application generates an error and discards the message.

The encodingStyle Attribute

The encodingStyle attribute is used to define the data types used in the document. This attribute may appear on any SOAP element, and applies to the element's contents and all child elements.
A SOAP message has no default encoding.

Syntax

soap:encodingStyle="URI"

The SOAP Header Element

The optional SOAP Header element contains application-specific information (like authentication, payment, etc) about the SOAP message.
If the Header element is present, it must be the first child element of the Envelope element.
Note: All immediate child elements of the Header element must be namespace-qualified.
<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Header>
  <m:Trans xmlns:m="http://www.w3schools.com/transaction/"
  soap:mustUnderstand="1">234
  </m:Trans>
</soap:Header>
...
...
</soap:Envelope>
The example above contains a header with a "Trans" element, a "mustUnderstand" attribute with a value of 1, and a value of 234.
SOAP defines three attributes in the default namespace ("http://www.w3.org/2001/12/soap-envelope"). These attributes are: mustUnderstand, actor, and encodingStyle.
The attributes defined in the SOAP Header defines how a recipient should process the SOAP message.

The mustUnderstand Attribute

The SOAP mustUnderstand attribute can be used to indicate whether a header entry is mandatory or optional for the recipient to process.
If you add mustUnderstand="1" to a child element of the Header element it indicates that the receiver processing the Header must recognize the element. If the receiver does not recognize the element it will fail when processing the Header.

Syntax

soap:mustUnderstand="0|1"

Example

<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Header>
  <m:Trans xmlns:m="http://www.w3schools.com/transaction/"
  soap:mustUnderstand="1">234
  </m:Trans>
</soap:Header>
...
...
</soap:Envelope>

The actor Attribute

A SOAP message may travel from a sender to a receiver by passing different endpoints along the message path. However, not all parts of a SOAP message may be intended for the ultimate endpoint, instead, it may be intended for one or more of the endpoints on the message path.
The SOAP actor attribute is used to address the Header element to a specific endpoint.
Syntax
soap:actor="URI"
Example
<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Header>
  <m:Trans xmlns:m="http://www.w3schools.com/transaction/"
  soap:actor="http://www.w3schools.com/appml/">234
  </m:Trans>
</soap:Header>
...
...
</soap:Envelope>

The encodingStyle Attribute

The encodingStyle attribute is used to define the data types used in the document. This attribute may appear on any SOAP element, and it will apply to that element's contents and all child elements.
A SOAP message has no default encoding.
Syntax
soap:encodingStyle="URI"




The SOAP Body Element

The required SOAP Body element contains the actual SOAP message intended for the ultimate endpoint of the message.
Immediate child elements of the SOAP Body element may be namespace-qualified.
Example
<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Body>
  <m:GetPrice xmlns:m="http://www.w3schools.com/prices">
    <m:Item>Apples</m:Item>
  </m:GetPrice>
</soap:Body>

</soap:Envelope>

The example above requests the price of apples. Note that the m:GetPrice and the Item elements above are application-specific elements. They are not a part of the SOAP namespace.
A SOAP response could look something like this:
<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Body>
  <m:GetPriceResponse xmlns:m="http://www.w3schools.com/prices">
    <m:Price>1.90</m:Price>
  </m:GetPriceResponse>
</soap:Body>

</soap:Envelope>


The SOAP Fault Element

The optional SOAP Fault element is used to indicate error messages.
If a Fault element is present, it must appear as a child element of the Body element. A Fault element can only appear once in a SOAP message.
The SOAP Fault element has the following sub elements:
Sub ElementDescription
<faultcode>A code for identifying the fault
<faultstring>A human readable explanation of the fault
<faultactor>Information about who caused the fault to happen
<detail>
Holds application specific error information related to the Body element
SOAP Fault Codes
The faultcode values defined below must be used in the faultcode element when describing faults:
ErrorDescription
VersionMismatchFound an invalid namespace for the SOAP Envelope element
MustUnderstandAn immediate child element of the Header element, with the mustUnderstand attribute set to "1", was not understood
ClientThe message was incorrectly formed or contained incorrect information
ServerThere was a problem with the server so the message could not proceed



The HTTP Protocol

HTTP communicates over TCP/IP. An HTTP client connects to an HTTP server using TCP. After establishing a connection, the client can send an HTTP request message to the server:
POST /item HTTP/1.1
Host: 189.123.345.239
Content-Type: text/plain
Content-Length: 200
The server then processes the request and sends an HTTP response back to the client. The response contains a status code that indicates the status of the request:
200 OK
Content-Type: text/plain
Content-Length: 200
In the example above, the server returned a status code of 200. This is the standard success code for HTTP.
If the server could not decode the request, it could have returned something like this:
400 Bad Request
Content-Length: 0

SOAP HTTP Binding

A SOAP method is an HTTP request/response that complies with the SOAP encoding rules.
HTTP + XML = SOAP
A SOAP request could be an HTTP POST or an HTTP GET request.
The HTTP POST request specifies at least two HTTP headers: Content-Type and Content-Length.

Content-Type

The Content-Type header for a SOAP request and response defines the MIME type for the message and the character encoding (optional) used for the XML body of the request or response.

Syntax

Content-Type: MIMEType; charset=character-encoding

Example

POST /item HTTP/1.1
Content-Type: application/soap+xml; charset=utf-8

Content-Length

The Content-Length header for a SOAP request and response specifies the number of bytes in the body of the request or response.

Syntax

Content-Length: bytes

Example

POST /item HTTP/1.1
Content-Type: application/soap+xml; charset=utf-8
Content-Length: 250

A SOAP Example

In the example below, a GetStockPrice request is sent to a server. The request has a StockName parameter, and a Price parameter that will be returned in the response. The namespace for the function is defined in "http://www.example.org/stock".
A SOAP request:
POST /InStock HTTP/1.1
Host: www.example.org
Content-Type: application/soap+xml; charset=utf-8
Content-Length: nnn

<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Body xmlns:m="http://www.example.org/stock">
  <m:GetStockPrice>
    <m:StockName>IBM</m:StockName>
  </m:GetStockPrice>
</soap:Body>

</soap:Envelope>
The SOAP response:
HTTP/1.1 200 OK
Content-Type: application/soap+xml; charset=utf-8
Content-Length: nnn

<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Body xmlns:m="http://www.example.org/stock">
  <m:GetStockPriceResponse>
    <m:Price>34.5</m:Price>
  </m:GetStockPriceResponse>
</soap:Body>

</soap:Envelope>





Posted by at No comments:
Subscribe to: Posts (Atom)