JSON and PHP encode array/dictionary

[garethc]

Hi All,

Just looking for some advice on a problem I'm having please. The scenario is that I have a database with a list of blog postings. I want to extract that list using PHP and transfer it to an iPhone app using JSON (I think).

So I'm trying to encode something like this into JSON, but don't know whether it's possible or the best approach.

messageType : NewContentCheck
Post ID : 1
Date Modified : 8/20/10
Post ID : 2
Date Modified : 8/1/10
Post ID : 10
Date Modified : 8/17/10

etc. etc. There'll be a number of posts from 1 to X and I need the messageType to appear as a header.

I've been playing around for a few hours now but either don't get a valid JSON string, or I get the messageType printed multiple times.

Code is based on variants of:

$returnedRows = mysql_num_rows($result);

$messageType = "NewContentCheck";
$postObject['messageType'] = $messageType;


if ($returnedRows > 0) {
	for ($i = 1; $i <= $returnedRows; $i++) {
		// Get each individual row of data and create a JSON string of each
		$row  = mysql_fetch_object($result);
		$postObject['posts'] = array($row->ID, $row->post_modified);
		echo json_encode($postObject);
	} 


}

Maybe it's not possible to encode this as a JSON? I wondered about just sending through lots of individual JSON strings separated with a pipe | and splitting them at the other end.

Any advice gratefully received.

Thanks,

Gareth.

P.S. Fairly new to PHP... : )

[garethc]

Worked it out..... will put up in case helps anyone else:

// Set message type, App ID and number of post objects included as header in JSON string
$postObject['messageType'] = $messageType;
$postObject['appID'] = $appID;
$postObject['numberOfModifiedPosts'] = $returnedRows;

if ($returnedRows > 0) {
	for ($i = 1; $i <= $returnedRows; $i++) {
		// Get each individual row of data and add an array of post objects
		$row  = mysql_fetch_object($result);
		$modifiedPosts[] = array('postID'=>$row->ID, 'dateModified'=>$row->post_modified);
	}

	// Add the modified post collection to our postObject
	$postObject['modifiedPosts'] = $modifiedPosts;

	// Encode the postObject to a JSON string
	echo json_encode($postObject);
}

Generates:

{
"messageType": "NewContentCheck",
"appID": "12345",
"numberOfModifiedPosts": 3,
"modifiedPosts": [
{
"postID": "1",
"dateModified": "2010-08-06 19:00:46"
},
{
"postID": "2",
"dateModified": "2010-08-06 19:00:46"
},
{
"postID": "5",
"dateModified": "2010-08-06 19:30:31"
}
]
}

[marciokoko]

hi, im currently using:

$rs = mysql_query("SELECT * FROM users");
while($obj = mysql_fetch_object($rs)) {
$arr[] = $obj;

to return an array of objects to an iOS app. Each item in the array is actually a dictionary entry, actually here is the echo of that array:

[
{"id":"1","name":"Marcio Valenzuela","pass":"","udid":"269d4008ba6575b9ec51a7f3237e757c2bcd6bf6","timestamp":"0000-00-00 00:00:00","reglocation":""},
{"id":"2","name":"santi","pass":"","udid":"2031aafb778b3a27635ae38e4315f31bba956805","timestamp":"0000-00-00 00:00:00","reglocation":""},
{"id":"4","name":"xcodesimulator","pass":"","udid":"F6869FB4-2EBE-5D43-A62D-5D4007646764","timestamp":"2010-09-18 11:15:16","reglocation":""},
{"id":"5","name":"abusipad","pass":"","udid":"adf03902c18974c9d29edf27da779afa66438a3b","timestamp":"2010-09-18 11:18:52","reglocation":""}
]

It turns out i actually need that data as a dictionary because i need to pass both the name and userid to the next view controller. Is there an equivalent:

$rs = mysql_query("SELECT * FROM users");
while($obj = mysql_fetch_object($rs)) {
$dic[] = $obj;