Question

I use yii framework to create map application.In this application i use GeoExt and Openlayers.In this App user can draw polygon and save this for achieving this after user draw polygon and click on it(OpenLayers feature) i send polygon with ajax to save that on database but i can’t get any ajax data from controller action in yii framework.See below code!

var selectOptions = {
            clickout: true,
            onSelect: save
        };
        select = new OpenLayers.Control.SelectFeature(vectors, selectOptions);
        map.addControl(select);
var saveButton = new Ext.Button({
            text: 'Save',
            enableToggle: true,
            toggleGroup: toggleGroup,
            handler: function(toggled)
            {
                if(toggled){
                    polygon.deactivate();
                    modify.deactivate();
                    select.activate();
                }   
            }
function save(feature) {
        var geojson_format = new OpenLayers.Format.GeoJSON();
        var str = geojson_format.write(feature, true);
        Ext.MessageBox.prompt('Name', 'Please enter district name:', "Ok");
        <?php 
            echo CHtml::ajax(array(
                'url'=>array('site/test'),
                'data'=>array('polygon'=>'data'),
                'type'=>'POST',
                'success'=>"function(){
                        alert('ok');
                    }"
            ));
        ?>
        $("#output").val(str);
    }

in the save function i use yii Chtml::ajax to send polygon to Yii site controller test action in this php code i send polygon with ‘data’ for testing but in real i want to send str variable that is polygon geojson object to controller action.At the end of function i use $(“#output”).val(str); for testing geojson str var i see the output in the output textarea but i don’t know why data doesn’t send to controller action!
controller action Code

   class SiteController extends Controller
   {
public $polygon;
public function actionTest()
    {
       if(isset($_POST['polygon']))
            $this->polygon=$_POST['polygon'];

         $this->render("test", array('polygon'=>$this->polygon));
}

for testing functionality i create a polygon in the map and click save button after this button is toggled i click on the created polygon i see polygon geojson object in the output textarea but when i want to see polygon object in the browser with http://localhost/FleetManagement/index.php/site/test i see only Null!!
test view code:

<?php 
    var_dump($polygon);
?>

Below is save function in the chrome developer tools!

function save(feature) {
        var geojson_format = new OpenLayers.Format.GeoJSON();
        var str = geojson_format.write(feature, true);
        Ext.MessageBox.prompt('Name', 'Please enter district name:', "Ok");
        jQuery.ajax({'url':'/FleetManagement/index.php/site/test','data':{'polygon':'data'},'type':'POST','cache':false});            $("#output").val(str);
    }

when i debug i see JQuery.ajax line execute but i don’t know this line can send data or no! because when i see test view i only see Null!
In the above code i can see success alert but i can’t see site controller polygon in test view and $polygon is Null!

Answer 1

I believe that your code is probably working – adding a var_dump($_POST) in actionTest() would be a good place to start.

Since you’re making an AJAX call, the $this->render() is not returning to the browser the way you’re expecting. I would imagine that in the Chrome Developer Tools, Network tab, then then Response tab, you’ll see ‘data’.

In general, to get data back, you’d want something like:

public function actionTest()
{
   if(isset($_POST['polygon']))
        $polygon = $_POST['polygon'];
    else
        $polygon = NULL;
    echo CJSON::encode(array('polygon'=>$polygon));
}

To access the returned data, you could use a callback in your AJAX, e.g. :

     <?php 
        echo CHtml::ajax(array(
            'url'=>array('site/test'),
            'data'=>array('polygon'=>'data'),
            'type'=>'POST',
            'dataType': 'json',
            'success' : "function(data) { console.log(data.polygon) }",
        ));
    ?>

This would log the value of polygon to the console . . . modify the success function to output this somewhere more useful.

Your current method sounds as if it’s failing since you’re accessing site/test directly in your browser via the address bar, which means that $_POST won’t have anything in it.