I'm using the following function to add content to an excel file using PHP :
function __writeString($row, $col, $value ) {
$L = strlen($value);
$this->file .= pack("ssssss", 0x204, 8 + $L, $row, $col, 0x0, $L);
$this->file .= $value;
}
I would like to know how I can add images in my cells the same way, by supplying its url as a value for instance.
Take a look at this: PHPExcel. It will provide you will all the tools you need to read and write Excel from PHP.
Once you have PHPExcel installed, you can use something like this to insert:
$objDrawing = new PHPExcel_Worksheet_Drawing();
$objDrawing->setPath('./images/picture.png');
$objDrawing->setCoordinates('A11');