Question

I created an object from PHP with json encode, but I am having difficulty using the data to get the image width and height in the object.

This is how I created the objects:

    $get = mysql_query("SELECT x,y,img,bid FROM player WHERE uid='1'");
    while($row = mysql_fetch_assoc($get)){
        $data[$row['x']] = Array();
        $data[$row['x']][$row['y']][0] = $row['bid'];  // 1
        $data[$row['x']][$row['y']][1] = $row['img'];  // test.png
        }
$data1 = json_encode($data);    

See comments for test data used.

I assign this $data1 to variable sdata.

Now in my JavaScript I am trying to do this:

 imgwidth = sdata[i][j][1].width;
 imgheight = sdata[i][j][1].height;

But I get undefined, is there something I am missing out ?

Answer 1

If I read this correctly, sdata[i][j][1] in JS will map to the string "test.png". That is, the JSON is encoding the filename of the image, not the image data itself. So sdata[i][j][1].width is asking for the width property of a string "test.png", which doesn’t exist.

You’ll probably need to open the image on the server side (using ImageMagick or GD in PHP) and pull out the properties from there.

Have a look at the getimagesize() function as a starting point.