osmwp.github.com/development_javascript_JSON.html at master · osmwp/osmwp.github.com · GitHub

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<!DOCTYPE html
 PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<htmlxmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

<head>
<metahttp-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Mobile Widgets</title>
<linkrel="stylesheet" href="style/style.css" />
<linkrel="shortcut icon" href="images/favicon.ico" type="image/x-icon" />
<scripttype="text/javascript" src="js/StructureElts.js"></script>
<scripttype="text/javascript" src="js/Structure.js"></script>
<scripttype="text/javascript" src="js/DocElements.js"></script>
</head>

<body>

<scripttype="text/javascript">
<!--
idCurrentPage="development_javascript_JSON";
beginPage();
//-->
</script>


<h1class="title">JSON Javascript library</h1>

<scripttype="text/javascript">
<!--
addIndex();
//-->
</script>


<pclass="note warning">
<b>Warning:</b><br/>
This tutorial covers only Mobile Widgets versions.<br/>
Tiny Widgets don't support JSON</a>.
</p>

<scripttype="text/javascript">addTitle("Description",1);</script>

<p>
Load and parse JSON data.
</p>

<scripttype="text/javascript">addTitle("Methods",1);</script>

<p>
<b>int open (String buffer, int mode)</b>:<br/>
Create a JSON DOM by parsing the provided buffer or url according to mode.<br/>
The value returned must be used for all subsequent operations on this DOM.
</p>

<p>
<b>void close (int id)</b>:<br/>
Destroy the DOM and release any resources associated to <b>id</b>.
</p>

<p>
<b>bool find (int id, String path)</b>:<br/>
Set a pointer to an element defined by the path.<br/>
The form of this path is nodeName1/nodeName2/...<br/>
If the value of the node is an array and not an Object, then the form <b>index</b>
can be used instead.<br/>
Example: main/table*1/key points to the key element that is stored at the second
position inside the array associated to table, child of main, like in:
</p>
<textareawrap="off" readonly="readonly" rows="1" cols="80">
{"main" : { "table" : [ { "id" : 1234}, {"key" : 2} ] }, "list" : [ 1, 2] }}
</textarea>
<p>
This obviously implies that the structure is known in advance!
</p>

<p>
<b>int/String getValue (int id)</b>:<br/>
Returns the value located to the previous find command.<br/>
This will return 0 for types other that string, number and constants (true, false and null).<br/>
In the previous example, returns the number 2.
</p>

<p>
<b>int getType (int id)</b>:<br/>
Returns the type of the value located to the previous find command.<br/>
In the previous example, returns <b>JSON.NUMBER</b>.
</p>

<p>
<b>int getSize (int id)</b>:<br/>
Returns the size of the value located to the previous find command.<br/>
Returns always 1 except for arrays.
</p>
<br/>

<scripttype="text/javascript">addTitle("Constants",1);</script>

<p>
<b>NUMBER, STRING, OBJECT, ARRAY, TRUE, FALSE, NULL, ERROR</b>:<br/>
Types returned by the <b>JSON.getType ()</b> method.
</p>

<p>
<b>BUFFER, URL, KEEP_ALIVE, DEBUG, ASYNC</b>:<br/>
Values that can be used for the <b>mode</b> argument of the <b>JSON.open()</b> method.
</p>
<br/>

<scripttype="text/javascript">addTitle("Examples",1);</script>

<textareawrap="off" readonly="readonly" rows="10" cols="80">
function parseJson(){
 // Quotes are not interpreted in the script thanks to the slashes
 var jsondata = '{\"result\":\"myContent\",\"id\":1}'; // The corresponding Json string is: {"result":"myContent","id":1}
 // Parse Json response, like the Xml parser
 var id = JSON.open(jsondata , JSON.BUFFER);
 JSON.find(id, '/result');
 Browser.print('Result: '+JSON.getValue(id)); // Prints "Result: myContent"
 JSON.close(id); // Free all resources associated to the DOM
}
</textarea>
<br/>


<scripttype="text/javascript">
<!--
addBackPageNavigator('widgets_development_javascript_ref','');
//-->
</script>


<scripttype="text/javascript">
<!--
endPage();
//-->
</script>

</body>

</html>