JSON parse data in javascript from php

Question

I'm trying to retrieve data in a javascript file from a php file using json.

$items = array(); 
while($r = mysql_fetch_array($result)) { 
    $rows = array( 
        "id_locale" => $r['id_locale'], 
        "latitudine" => $r['lat'], 
        "longitudine" => $r['lng'] 
    ); 
    array_push($items, array("item" => $rows)); 
} 
ECHO json_encode($items);

and in the javascript file I try to recover the data using an ajax call:

$.ajax({
    type:"POST",
    url:"Locali.php",
    success:function(data){
        alert("1");
        //var obj = jQuery.parseJSON(idata);
        var json = JSON.parse(data);
        alert("2");
        for (var i=0; i<json.length; i++) {
            point = new google.maps.LatLng(json[i].item.latitudine,json[i].item.longitudine);
            alert(point);
        }
    }
})

The first alert is printed, the latter does not, it gives me error: Unexpected token <.... but I do not understand what it is.

Anyone have any idea where am I wrong?

I also tried to recover the data with jquery but with no positive results.

Don't use JSON.parse in your success function. Give your $.ajax attribute dataType: 'json' and then console.log the JSON response to see whether you got a null or an object with properties. If you got a null, something's wrong with the data in your PHP script. — N.B.
– N.B., Commented Nov 27, 2012 at 10:19
my JSON data is: [{"item":{"id_locale":"50","latitudine":"44.4794995","longitudine":"11.364192099999968"}}] in JSON lint the json file is ok — Stefania
– Stefania, Commented Nov 27, 2012 at 10:21
If You specify dataType: 'json' in Your jQuery AJAX call it should be enough in Your PHP script to do return $items; instead of echo json_encode($items);. — shadyyx
– shadyyx, Commented Nov 27, 2012 at 10:23

NappingRabbit · Accepted Answer · 2012-11-27 10:26:27Z

0

This should do it.

$.post("Locali.php",{
    // any parameters you want to pass
},function(d){
    alert("1");
    for (var i=0; i<d.length; i++) {
      point = new google.maps.LatLng(d[i].item.latitudine,d[i].item.longitudine);
      alert(point);
    }
}, 'json');

the PHP is fine if it is giving the response you mentioned above.

answered Nov 27, 2012 at 10:26

NappingRabbit

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2 Comments

Stefania Over a year ago

how can I take the parameters?

NappingRabbit Over a year ago

you were not passing any parameters in your question, but I left the area open because I almost always pass something. they would be in array format. simpler; where the comment is you could pass comma delineated data like name:value, name2:value2

akki · Accepted Answer · 2012-11-27 10:36:17Z

0

I think u should look more for the data you are getting from the php file. Definitely this is a parse error and must be missing some bracket/something else, ultimately not making the data returned to be a json parseable string.

answered Nov 27, 2012 at 10:36

akki

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Comments

shadyyx · Accepted Answer · 2012-11-27 11:01:55Z

0

You should be Ok with this slight modifications:

$items = array(); 
while($r = mysql_fetch_array($result)) { 
    $items[] = array( 
        "id_locale" => $r['id_locale'], 
        "latitudine" => $r['lat'], 
        "longitudine" => $r['lng'] 
    ); 
} 
echo json_encode($items);

And the jQuery:

$.ajax({
    type:"POST",
    dataType: 'json',
    url:"Locali.php",
    success:function(data){
        console.log(data);
        for (var i=0; i<data.length; i++) {
            point = new google.maps.LatLng(data[i].item.latitudine,data[i].item.longitudine);
            alert(point);
        }
    }
})

edited Nov 27, 2012 at 11:01

answered Nov 27, 2012 at 10:27

shadyyx

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12 Comments

shadyyx Over a year ago

Didn't... If You specify the dataType:'json' it is not required to json_encode the PHP response...This is how I use it in many projects...

NappingRabbit Over a year ago

I have never heard of that before. maybe I will try it sometime. I would think that the PHP response would just be Array()

shadyyx Over a year ago

The difference is I am using return $items; instead of echoing json string... So any array or object get passed directly to AJAX call as response...

NappingRabbit Over a year ago

so you are saying that PHP automatically encodes arrays into JSON format. I did not know that. It serializes the array no matter what type of characters are used?

shadyyx Over a year ago

@NappingRabbit Sorry for the mistyfication - I looked at out framework and the base controller class. It checks whether the request comes from AJAX (the call contains parameter async=1) and in that case it takes the response from the action called (in my case the return) and echoes it json_encoded... Sorry, my bad.

|

JPR · Accepted Answer · 2012-11-27 11:52:01Z

0

data $.ajax({ type:"POST", dataType: json, url:"Locali.php", success:function(data){ for (i in data) { point = new google.maps.LatLng(json[i].item.latitudine,json[i].item.longitudine); alert(point);
} } })

Try it like that.

edited Nov 27, 2012 at 11:52

answered Nov 27, 2012 at 10:26

JPR

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1 Comment

NappingRabbit Over a year ago

variable json is not defined (when making variable point), return variable in what you wrote is data

Andrei Cristian Prodan · Accepted Answer · 2012-11-27 10:27:55Z

-1

yeah just try

for (var i=0; i<json[0].length; i++) {

cause you have an object there..

answered Nov 27, 2012 at 10:27

Andrei Cristian Prodan

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