JSON JSONP

JSONP

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JSONP is a method for sending JSON data without worrying about cross-domain issues.

JSONP does not use the XMLHttpRequest object.

JSONP uses the <script> tag instead.

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JSONP Intro

JSONP stands for JSON with Padding.

Requesting a file from another domain can cause problems, due to cross-domain policy.
Requesting an external script from another domain does not have this problem.
JSONP uses this advantage, and request files using the script tag instead of the XMLHttpRequest object.

<script src="demo_jsonp.php">

The Server File

The file on the server wraps the result inside a function call:

Example

<?php
$myJSON = '{ "name":"John", "age":30, "city":"New York" }';

echo "myFunc(".$myJSON.");";
?>

The result returns a call to a function named "myFunc" with the JSON data as a parameter.
Make sure that the function exists on the client.

The JavaScript function

The function named "myFunc" is located on the client, and ready to handle JSON data:

Example

function myFunc(myObj) {
    document.getElementById("demo").innerHTML = myObj.name;
}

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