tFPDF generates an empty pdf file

问题

I am trying to generate a PDF file in PHP using the tFPDF library. I started with FPDF and it worked fine except that the UTF-8 characters were garbled. After some searching, I found that one could implement tFPDF to include UTF-8 characters in a PDF file. But all my attempts have resulted in an empty file that cannot be opened--0 KB file written to my hard drive and "There's a problem with the file format" message when I double click it. Here is my code. I'm getting no PHP errors in the error log so it's a little difficult to tell what is going wrong.

protected function getPDFFileData($diagnosis_id)
{
    define('FPDF_FONTPATH', JPATH_COMPONENT.'/helpers/font/');
    require_once JPATH_COMPONENT.'/helpers/tfpdf.php';
    //require_once JPATH_COMPONENT.'/helpers/fpdf.php';

    $item = $this->getItem($diagnosis_id);

    $pdf = new tFPDF('P', 'mm', 'Letter');
    //$pdf = new FPDF('P', 'mm', 'Letter');
    $pdf->AddPage();

    $fontname = "dejavusans";
    $pdf->AddFont($fontname, '', 'DejaVuSans.ttf', true);
    $pdf->AddFont($fontname, 'B', 'DejaVuSans-Bold.ttf', true);
    $pdf->AddFont($fontname, 'I', 'DejaVuSans-Oblique.ttf', true);
    $pdf->SetFont($fontname, '', 10);

    /* $fontname = "helvetica";
    $pdf->AddFont($fontname, '', 'helvetica.php');
    $pdf->AddFont($fontname, 'B', 'helveticab.php');
    $pdf->AddFont($fontname, 'I', 'helveticai.php');
    $pdf->SetFont($fontname, '', 10); */

    $domain_header = "Domain".chr(160).($item->ordinal).".".chr(160).($item->domain_label);
    $pdf->Cell(90, 6, $domain_header, 0, 0, 'L');
    $class_header = "Class".chr(160).($item->domain_class_ordinal).".".chr(160).($item->class_label);
    $pdf->Cell(90, 6, $class_header, 0, 1, 'R');
    $pdf->Ln();
    $pdf->SetFont($fontname, '', 10);
    $domain_class_info = "Domain".chr(160).($item->ordinal).chr(160).chr(183).chr(160)."Class".chr(160).($item->domain_class_ordinal).chr(160).chr(183).chr(160)."Diagnosis Code".chr(160).($item->diagnosis_code);
    $pdf->Cell(40, 6, $domain_class_info);
    $pdf->Ln();
    $pdf->SetFont($fontname, '', 14);
    $pdf->Cell(40, 8, $item->diagnosis_label);
    $pdf->Ln();

    // More code that generates more text . . . 

    return $pdf->Output('S');
}

回答1:

Adding a new font requires two steps:

Generation of the font definition file
Declaration of the font in the script

In your case, we need to generate the font definition file. For example, we can use the command line:

~/w/t/fpdf181> php makefont/makefont.php font/dejavu-sans/DejaVuSans.ttf cp1252
Font file compressed: DejaVuSans.z
Font definition file generated: DejaVuSans.php

Add font

$fontname = "DejaVuSans";
$pdf->AddFont($fontname, '', 'DejaVuSans.php', true);

http://www.fpdf.org/en/tutorial/tuto7.htm

[EDIT]

From your comment, you used the library http://www.fpdf.org/en/script/script92.php

1) Dejavu already added to tfpdf/font/unifont folder. And, the name should be

$fontname = 'DejaVu';

2) If we want to add our custom font folder, we need to override _SYSTEM_TTFONTS

// Optionally define the filesystem path to your system fonts
// otherwise tFPDF will use [path to tFPDF]/font/unifont/ directory
// define("_SYSTEM_TTFONTS", "C:/Windows/Fonts/");

tfpdf/tfpdf.php

 if (defined("_SYSTEM_TTFONTS") && file_exists(_SYSTEM_TTFONTS.$file )) 
 {
    $ttffilename = _SYSTEM_TTFONTS . $file ;
 }
 else {
    $ttffilename = $this->_getfontpath().'unifont/'.$file ;
 }

I created an sample test:

<?php

// Optionally define the filesystem path to your system fonts
// otherwise tFPDF will use [path to tFPDF]/font/unifont/ directory

//define("_SYSTEM_TTFONTS", "font/dejavu-sans/");

require "tfpdf.php";

$pdf = new tFPDF('P', 'mm', 'Letter');
$pdf->AddPage();

//Example object data
/** @var StdClass $item */
$item = new StdClass();
$item->ordinal = 'Item Ordinal';
$item->domain_label = "Item Domain Label";
$item->domain_class_ordinal = "Item Domain Class Ordinal";
$item->class_label = 'Item Class Label';
$item->diagnosis_code = 'Item Diagnosis Code';
$item->diagnosis_label = 'Item Diagnosis Label';

// Add a Unicode font (uses UTF-8)
$fontname = 'DejaVu';
$pdf->AddFont($fontname,'','DejaVuSans.ttf',true);
$pdf->AddFont($fontname, 'I', 'DejaVuSans-Oblique.ttf', true);
$pdf->AddFont($fontname, 'B', 'DejaVuSans-Bold.ttf', true);
$pdf->SetFont('DejaVu','',14);

$domain_header = "Domain".chr(160).($item->ordinal).".".chr(160).($item->domain_label);
$pdf->Cell(90, 6, $domain_header, 0, 0, 'L');
$class_header = "Class".chr(160).($item->domain_class_ordinal).".".chr(160).($item->class_label);
$pdf->Cell(90, 6, $class_header, 0, 1, 'R');
$pdf->Ln(10);
$pdf->SetFont($fontname, '', 10);
$domain_class_info = "Domain".chr(160).($item->ordinal).chr(160).chr(183).chr(160)."Class".chr(160).($item->domain_class_ordinal).chr(160).chr(183).chr(160)."Diagnosis Code".chr(160).($item->diagnosis_code);
$pdf->Cell(40, 6, $domain_class_info);
$pdf->Ln(10);
$pdf->SetFont($fontname, '', 14);
$pdf->Cell(40, 8, $item->diagnosis_label);
$pdf->Ln(10);

$pdf->Output('S');

回答2:

This is what ended up working for me. I had to delete all calls to the PHP function chr(), and use the specific UTF-8 syntax for characters outside the ASCII set (e.g., '\u2022' for a bullet character). I believe I found the tip to use the json_decode() function on these characters to render the desired output somewhere on stackoverflow. I also found that I could not get results calling the Output() function with parameter 'S' to return a string, so I used a filename parameter to write the output to a file on the server. Here is the revised function.

protected function getPDFFileData($diagnosis_id, $output_file_name)
{
    define('FPDF_FONTPATH', JPATH_COMPONENT.'/helpers/fpdf181/font/');
    require_once JPATH_COMPONENT.'/helpers/fpdf181/tfpdf.php';

    $item = $this->getItem($diagnosis_id);

    $pdf = new tFPDF('P', 'mm', 'Letter');
    $pdf->AddPage();

    $fontname = "DejaVu";
    $pdf->AddFont($fontname, '', 'DejaVuSans.ttf', true);
    $pdf->AddFont($fontname, 'B', 'DejaVuSans-Bold.ttf', true);
    $pdf->AddFont($fontname, 'I', 'DejaVuSans-Oblique.ttf', true);
    $pdf->SetFont($fontname, '', 10);

    $bullet_char_uni = '\u2022';
    $bullet_char = json_decode('"'.$bullet_char_uni.'"');

    $domain_header = "Domain ".($item->ordinal).". ".($item->domain_label);
    $pdf->Cell(90, 6, $domain_header, 0, 0, 'L');
    $class_header = "Class ".($item->domain_class_ordinal).". ".($item->class_label);
    $pdf->Cell(90, 6, $class_header, 0, 0, 'R');
    $pdf->Ln();
    $pdf->SetFont($fontname, '', 10);
    $diagnosis_code = "Domain ".($item->ordinal)." ".$bullet_char." Class ".($item->domain_class_ordinal)." ".$bullet_char." Diagnosis Code ".($item->diagnosis_code);
    $pdf->Cell(40, 6, $diagnosis_code, 0, 1, 'L');
    $pdf->Ln();
    $pdf->SetFont($fontname, '', 14);
    $pdf->Cell(40, 8, $item->diagnosis_label, 0, 1, 'L');

    // More code that generates more text . . . 

    $output = $pdf->Output($output_file_name);
    return $output; 
}

来源：https://stackoverflow.com/questions/51794930/tfpdf-generates-an-empty-pdf-file

标签

php

utf-8

fpdf