generating multiple pdf document and merge into one - codeigniter

Question

This is my controller function where i am running a loop to create multiple document pdf
and merge into one.
public function tick_pdf(){
$tt='';
$name="iftekhar";
$title="Event Football";
$num=4;
for($i=0;$i<4;$i++){
$this->pdfHeader($row->EventId);
$this->pdf->fontpath = 'font/';
//$this->pdf->AddPage();
$this->pdf->Ln(10);
$this->pdf->SetFont('Arial','B',12);
$this->pdf->Cell(10);
$this->pdf->Cell(60,10,"Name",0,0,'L');
$this->pdf->Cell(10,10,":",0,0,'L');
$this->pdf->MultiCell(60,10,$name,0,1);
$this->pdf->SetFont('Arial','B',12);
$this->pdf->Cell(10);
$this->pdf->Cell(60,10,"Title",0,0,'L');
$this->pdf->Cell(10,10,":",0,0,'L');
$this->pdf->MultiCell(60,10,$title,0,1);
$this->pdf->SetFont('Arial','B',12);
$this->pdf->Cell(10);
$this->pdf->Cell(60,10,"Number",0,0,'L');
$this->pdf->Cell(10,10,":",0,0,'L');
$this->pdf->MultiCell(60,10,$num,0,1);
$this->pdf->SetFont('Arial','B',12);
$this->pdf->Cell(10);
$this->pdf->Cell(60,10,"Date",0,0,'L');
$this->pdf->Cell(10,10,":",0,0,'L');
$this->pdf->MultiCell(60,10,$date,0,1);
$tt.=$this->pdf->Output('', 'S');
}
echo $tt;
}
but I am gettiin an error in browser
"Undefined index: data
Filename: libraries/fpdf.php
Line Number: 1659" I am using fpdf for generating pdf

Answer 1

If you need to create multiple PDF documents you will need several class instances. Actually you're working with only one instance.
Also it is not possible to concatenate a PDF document by simply concatenating their bytes ($tt .= ...). Generally it is not possible to send multiple PDF documents to the client in a single request.
If you want to create multiple pages, just remove the comment before AddPage(), delete the variable $tt and move the Output() call outside of the loop.