Webservice

What is a web service?

In simple word web services is a collection of standards or protocols for exchanging information between two devices or applications. Web service is language independent way of communication. We just look bellow figure to more clear our concept.

In above figure you can see java can communicate to other languages like .net, PHP and vice versa by using web services i.e. web services has no language limitation.

Types of Web Services

There are mainly two types of web services.

1. SOAP web services.
2. RESTful web services.

SOAP Web Services :-

SOAP stands for Simple Object Access Protocol. It is a XML-based protocol for accessing web services.

SOAP is a W3C recommendation for communication between two applications.

It is platform independent and language independent. By using SOAP, you will be able to interact with other programming language applications.

Advantages of Soap Web Services

WS Security: SOAP defines its own security known as WS Security.

Language and Platform independent: SOAP web services can be written in any programming language and executed in any platform.

Disadvantages of Soap Web Services

Slow: SOAP uses XML format that must be parsed to be read. It defines many standards that must be followed while developing the SOAP applications. So it is slow and consumes more bandwidth and resource.

WSDL dependent: SOAP uses WSDL and doesn't have any other mechanism to discover the service.

Web Service Components

1. SOAP
2. WSDL
3. UDDI

SOAP: SOAP is an acronym for Simple Object Access Protocol.

WSDL: WSDL is an acronym for Web Services Description Language. WSDL is pronounced as wiz-dull.

WSDL is a xml document containing information about web services such as method name, method parameter and how to access it.

WSDL is a part of UDDI. It acts as a interface between web service applications.

UDDI: UDDI is an acronym for Universal Description, Discovery and Integration.

UDDI is a XML based framework for describing, discovering and integrating web services.

UDDI is a directory of web service interfaces described by WSDL, containing information about web services.

RESTful Web Services :-

REST stands for REpresentational State Transfer.

REST is an architectural style not a protocol.

Advantages of RESTful Web Services

Fast: RESTful Web Services are fast because there is no strict specification like SOAP. It consumes less bandwidth and resource.

Language and Platform independent: RESTful web services can be written in any programming language and executed in any platform.

Can use SOAP: RESTful web services can use SOAP web services as the implementation.

Permits different data format: RESTful web service permits different data format such as Plain Text, HTML, XML and JSON

Simple PHP mail Function

PHP mail Function

$to      = $email_id;
$subject = "";
$message = "Your mail Body Content. you also use here HTML Tags for better performence. ";
$headers = 'From: xyz@domainname.com' . "\r\n" .
    'Reply-To: xyz@domainname.com' . "\r\n" .
    'X-Mailer: PHP/' . phpversion();
$headers.= "MIME-Version: 1.0" . "\r\n";
$headers.= "Content-type:text/html;charset=UTF-8" . "\r\n";

$test=mail($to, $subject, $message, $headers);

PHP Magic Methods

PHP Magic Methods

1.      __construct()  :- This method is called when someone create the object of class. Constructor is use to load default variable or methods which is call default when page is load. Constructor also inherit like any other methods.

2.      __destruct()  :-  This magic method is called when object of your class is unset. It gets run when the object is destroyed, either expressly by us or when we're not using it any more and PHP cleans it up for us. The destructor lets us close up any external resources that were being used by the object.

3.       __get()  :-  it makes properties which actually don't exist appear as if they do. This method called when your object attempt to read property or variable of the class which is inaccessible or unavailable.

4.     __set()   :- This method called when object of your class attempts to set value of the property which is really inaccessible or unavailable in your class.

5.     __isset()   :- This magic methods trigger when isset() function is applied on any property of the class which is in accessible or unavailable.

6.       __unset()  :-  __unset is something opposite of isset method. This method triggers when unset() function called on inaccessible or unavailable property of the class.

7.       __sleep()   :-  this methods trigger when you are going to serialize your class object. When the object is serialised and then unserialised then these types of references are useless since the target may no longer be present or valid.

8.       __wakeup()  :- this is exactly opposite of sleep method and allows you to alter the behaviour of the unserialisation of the object.  

9.       __tostring()   :-  This method executes when you are using echo on your object. Definitely saving the best until last, the __toString method is a very handy addition to our toolkit.

MVC Architecture In PHP

MVC Architecture

Model

The Model is the name given to the permanent storage of the data used in the overall design. It must allow access for the data to be viewed, or collected and written to, and is the bridge between the View component and the Controller component in the overall pattern.

One important aspect of the Model is that it’s technically “blind” – by this I mean the model has no connection or knowledge of what happens to the data when it is passed to the View or Controller components. It neither calls nor seeks a response from the other parts; its sole purpose is to process data into its permanent storage or seek and prepare data to be passed along to the other parts.

The Model's job is to represent the problem domain, maintain state, and provide methods for accessing and mutating the state of the application. The Model layer is typically broken down into several different layers:

• Service layer - this layer provides cohesive, high-level logic for related parts of an application. This layer is invoked directly by the Controller and View helpers.
• Data Access layer - (ex. Data Gateway, Data Access Object) this layer provides access to the persistence layer. This layer is only ever invoked by Service objects. Objects in the data access layer do not know about each other.
• Value Objects layer - this layer provides simple, data-oriented representations of "leaf" nodes in your model hierarchy.

View

The View is where data, requested from the Model, is viewed and its final output is determined. Traditionally in web apps built using MVC, the View is the part of the system where the HTML is generated and displayed. The View also ignites reactions from the user, who then goes on to interact with the Controller. The basic example of this is a button generated by a View, which a user clicks and triggers an action in the Controller.

The View's job is to translate data into a visual rendering for response to the Client (ie. web browser or other consumer). The data will be supplied primarily by the Controller; however, the View may also have a helper that can retrieve data that is associated with the rendering and not necessarily with the current request

Controller

The final component of the triad is the Controller. Its job is to handle data that the user inputs or submits, and update the Model accordingly. The Controller’s life blood is the user; without user interactions, the Controller has no purpose. It is the only part of the pattern the user should be interacting with.

The Controller can be summed up simply as a collector of information, which then passes it on to the Model to be organized for storage, and does not contain any logic other than that needed to collect the input. The Controller is also only connected to a single View and to a single Model, making it a one way data flow system, with handshakes and signoffs at each point of data exchange.

It’s important to remember the Controller is only given tasks to perform when the user interacts with the View first, and that each Controller function is a trigger, set off by the user’s interaction with the View.

The Controller's job is to translate incoming requests into outgoing responses. In order to do this, the controller must take request data and pass it into the Service layer. The service layer then returns data that the Controller injects into a View for rendering. This view might be HTML for a standard web request; or, it might be something like JSON (JavaScript Object Notation) for a RESTful API request.

JSON Introduction

JSON - JavaScript Object Notation

               JSON is a lightweight text-based open standard data-interchange format. It is human readable. JSON is derived from a subset of JavaScript programming language. It is entirely language independent and can be used with most of the modern programming languages.

Key Points:

1.    There are four basic data types strings, numbers, booleans and null.
2. Objects are wrapped within ‘{’ and ‘}’. It is list of label – value pair.
3. Array are enclosed by ‘[’ and ‘]’. It is list of values.
4. Both object and array can be nested.

with the reference for more

 W3resources

Advantages of JSON:

1. Faster -:  JSON syntax is very easy to use. Which provide us a easy parsing of the data and faster execution of the data.

2. Portable -: It has wide range of supported browser compatibility with the operating systems so doesn’t require much effort to make it all browser compatible. JSON is portable because parsers and writers are available for many, many languages. It is the best way to transmit complex structures like arrays and objects, and have it still be compatible with multiple languages.

3. Server Parsing -: JSON server side parsing is strong point that indicates us to use the JSON on server side.

4. Tool for sharing data -: JSON is the best tool for the sharing data of any size even audio, video etc. This is because JSON stores the data in the arrays so data transfer makes easier. For this reason, JSON is a superior file format for web APIs and for web development.

5. Structure -: JSON provides structure because the data you transmit with it can have consistent formatting. This is instead of transmitting back plain-text (i.e. unformatted) data, like comma-separated or delimited data.

6. API -: API is the most widely used area where JSON is used for data exchange. Specially, web applications those have a social face, it has become obvious now that they have an API, so that developers can consume the huge amount of data collected by the app and then can create derivative apps.

Upload multiple images using Ajax

Upload multiple images using Ajax

index.html

<html>
<head>
<script src="https://code.jquery.com/jquery-2.1.1.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function (e) {
    $("#uploadF").on('submit',(function(e) {
        e.preventDefault();
        $.ajax({
            url: "upload.php",
            type: "POST",
            data:  new FormData(this),
            contentType: false,
            cache: false,
            processData:false,
            success: function(data){
            $("#gallery").html(data);
            },
              error: function(){}            
       });
    }));
});
</script>
</head>
<body>
    <div class="gallery-bg">
            <form id="uploadF" action="" method="post">
                <div id="gallery">No Images in Gallery</div>
                       <div id="uploadFormLayer">
                            <p class="txt-subtitle">Upload Multiple Image:</p>
                            <!-- <p><input name="userImage" type="file" class="inputFile" /><p>-->
                            <p><input name="userImage[]" type="file" /><p>
                          <p><input name="userImage[]" type="file" /><p>
                          <p><button id="Submit" value="Submit" name="Submit">Submit</button><p>
</div>
</form>

<input type="submit" value="Submit" />
</div>
</body>
</html>




upload.php


<?php
if(is_array($_FILES))
{
    foreach ($_FILES['userImage']['name'] as $name => $value)
    {
        if(is_uploaded_file($_FILES['userImage']['tmp_name']))
        {
            $sourcePath = $_FILES['userImage']['tmp_name'];
            $targetPath = "images/".$_FILES['userImage']['name'];
            if(move_uploaded_file($sourcePath,$targetPath))
            {
?>
                <img src="<?php echo $targetPath; ?>" width="150px" height="180px" />
<?php
            }
        }
    }
}
?>