JSON

From MapbenderWiki

Java Script Object Notation

Contents 1 general 2 PHP 2.1 PHP-JSON 3 JavaScript 3.1 jQuery 4 AJAX 4.1 jQuery 5 Example

general

• Douglas Crockford on JSON
• a validator: http://www.jsonlint.com/

PHP

PHP 5.2.1 natively supports JSON (see JSON at php.net)

PHP-JSON

• Mapbender now (March 2007) uses JSON-PHP to support previous PHP versions.
• download
• Example: generate JSON string from object

//requires JSON library
require_once(dirname(__FILE__)."/../extensions/JSON.php");

//generate a PHP object, f.e.
$resultObj = array("id" => $row["wms_id"], "title" => $row["wms_title"], "abstract" => $row["wms_abstract"]);

//convert to JSON string
$json = new Services_JSON();
$output = $json->encode($resultObj);

header('Content-type: application/x-json');
echo $output;

• Example: generate object from JSON string

//requires JSON library
require_once(dirname(__FILE__)."/../extensions/JSON.php");

$object = $json->decode($jsonString);
print_r($object);

JavaScript

Tutorial

download

Example

var someObject = {};
..
// construct some object
..
// get the JSON string representation
someObject.toJSONString();

jQuery

The Library above rewritten for jQuery:

download

Example

var someObject = {};
..
// construct some object
..
// get the JSON string representation
$.toJSON(someObject);

AJAX

jQuery

Ajax → $.getJSON()

$.getJSON() sends an Ajax request via GET and returns a JavaScript object.

Example

see gazetteerMetadata

/php/mod_gazetteerMetadata.php

/php/mod_gazetteerMetadata_search.php