Grid with empy JSON store shows 1 record

[Dafram]

Hi!

I'm using ExtJs 4.1.0 and I have a grid with a JSON Store that shows the records of a MySQL table:

    Ext.define('modelRegole', {
        extend: 'Ext.data.Model',
        fields: [
            {name: 'idrego',   type: 'int'},
            {name: 'descri',   type: 'string'},
            {name: 'idtipo_m', type: 'string'},
            {name: 'active',   type: 'boolean'}
        ]
    });
    
    var storeRegole = Ext.create('Ext.data.Store', {
        autoDestroy: true,
            model: 'modelRegole',
            proxy: {
                type: 'ajax',
                url : 'storeRegole.php',
                reader: {
                    type: 'json'
                },
                actionMethods: {
                    read: 'POST'
                }
            },
        autoLoad: false
    });

    var gridRegole = Ext.create('Ext.grid.Panel', {
        id: 'id_gridRegole',
        store: storeRegole,
        title: 'Regole',
        frame: true,
        columns: [
            {
                text      : 'ID Regola',
                width     : 70,
                dataIndex : 'idrego'
            },
            {
                text      : 'Descrizione',
                width     : 400,
                dataIndex : 'descri'
            },
            {
                text      : 'Tipologia/e',
                width     : 400,
                dataIndex : 'idtipo_m'
            },
            {
                text      : 'Attiva',
                width     : 100,
                dataIndex : 'active'
            }
        ],
        height: 500,
        width: 900
    });

MySQL Table structure:

mysql> desc regole;
+----------+---------------+------+-----+---------+-------+
| Field    | Type          | Null | Key | Default | Extra |
+----------+---------------+------+-----+---------+-------+
| idrego   | int(11)       | NO   | PRI | NULL    |       |
| idtipo_m | varchar(2500) | NO   |     | NULL    |       |
| descri   | varchar(255)  | NO   |     | NULL    |       |
| active   | smallint(6)   | NO   |     | NULL    |       |
+----------+---------------+------+-----+---------+-------+

storeRegole.php:

$str = "select * from regole order by idrego";
$rst = mysql_query($str);
while ( $arr = mysql_fetch_array($rst) )
{
    $n++;
    $esito[] = $arr;
}
if ($n == 0)
    $esito[] = array();

echo json_encode($esito); 

If my table (regole) is empy, I see my grid with 1 empty record:

err.jpg
I suppose it is for:

if ($n == 0)
    $esito[] = array(); 

but if I don't use that php code, I have the same result.

$str = "select * from regole order by idrego";
$rst = mysql_query($str);
while ( $arr = mysql_fetch_array($rst) )
{
    $n++;
    $esito[] = $arr;
}
if ($n == 0)
{

}
else
{
    echo json_encode($esito);
} 

Suggestions?

Thanks in advance.

[Tim Toady]

edit--
Retracted my first post after looking at your php some more.

[Dafram]

I am assuming you are intending posart to be your root and not specifying it in your reader.

Ops, thank you, I made a mistake, the correct php code is:

$str = "select * from regole order by idrego";
$rst = mysql_query($str);
while ( $arr = mysql_fetch_array($rst) )
{
    $n++;
    $esito[] = $arr;
}
if ($n == 0)
{

}
else
{
    echo json_encode($esito);
} 

My question remains alive...

[Tim Toady]

I actually think I answered too quickly and when I looked at it again I didn't see the issue I thought I did. What is the json that is coming back?

[Dafram]

I can synthesize my problem so:

if I make a JSON grid store with this php code:

$esito[] = array();
echo json_encode($esito); 

I don't see an empty grid, but I see a grid with 1 (empty) record like this:

err.jpg

Why?

[Dafram]

I actually think I answered too quickly and when I looked at it again I didn't see the issue I thought I did. What is the json that is coming back?

If I make the echo of json_encode of an empty php array I have BLANK output (blank string).

See firebug:

firebug.png

[Tim Toady]

$esito[] = array(); 

This should create a record. It is a 2 dimensional array. If there are no records it should be a single empty array.

--edit--

Just to clarify what you want for when there are no records is

$esito = array(); 

[Dafram]

Thank you very much! Now it works:

<?php
$esito = array();
echo json_encode($esito);
?>

Here a live example: http://www.playersmagazine.it/smeraldo/empty_grid.html

[Tim Toady]

Your json coming back is

[[]] 

Is should be the following if the grid is empty.

[] 

[Dafram]

Thanks!