From e8fbfdeb6e7967029a54904daaabfa086251d704 Mon Sep 17 00:00:00 2001 From: Sashi20 Date: Tue, 18 Jul 2017 11:10:30 +0530 Subject: Created Certificate Interface --- pdf/fpdf/FAQ.htm | 341 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 341 insertions(+) create mode 100755 pdf/fpdf/FAQ.htm (limited to 'pdf/fpdf/FAQ.htm') diff --git a/pdf/fpdf/FAQ.htm b/pdf/fpdf/FAQ.htm new file mode 100755 index 0000000..05d85c6 --- /dev/null +++ b/pdf/fpdf/FAQ.htm @@ -0,0 +1,341 @@ + + + + +FAQ + + + + +

FAQ

1. What's exactly the license of FPDF? Are there any usage restrictions?
2. When I try to create a PDF, a lot of weird characters show on the screen. Why?
3. I try to generate a PDF and IE displays a blank page. What happens?
4. I can't make line breaks work. I put \n in the string printed by MultiCell but it doesn't work.
5. I try to display a variable in the Header method but nothing prints.
6. I defined the Header and Footer methods in my PDF class but nothing appears.
7. Accented characters are replaced by some strange characters like é.
8. I try to display the Euro symbol but it doesn't work.
9. I get the following error when I try to generate a PDF: Some data has already been output, can't send PDF file
10. I draw a frame with very precise dimensions, but when printed I notice some differences.
11. I'd like to use the whole surface of the page, but when printed I always have some margins. How can I get rid of them?
12. How can I put a background in my PDF?
13. How can I set a specific header or footer on the first page?
14. I'd like to use extensions provided by different scripts. How can I combine them?
15. How can I send the PDF by email?
16. What's the limit of the file sizes I can generate with FPDF?
17. Can I modify a PDF with FPDF?
18. I'd like to make a search engine in PHP and index PDF files. Can I do it with FPDF?
19. Can I convert an HTML page to PDF with FPDF?
20. Can I concatenate PDF files with FPDF?

+ +

+
1. What's exactly the license of FPDF? Are there any usage restrictions?
+FPDF is released under a permissive license: there is no usage restriction. You may embed it +freely in your application (commercial or not), with or without modifications. +
+
2. When I try to create a PDF, a lot of weird characters show on the screen. Why?
+These "weird" characters are in fact the actual content of your PDF. This behavior is a bug of +IE6. When it first receives an HTML page, then a PDF from the same URL, it displays it directly +without launching Acrobat. This happens frequently during the development stage: on the least +script error, an HTML page is sent, and after correction, the PDF arrives. +
+To solve the problem, simply quit and restart IE. You can also go to another URL and come +back. +
+To avoid this kind of inconvenience during the development, you can generate the PDF directly +to a file and open it through the explorer. +
+
3. I try to generate a PDF and IE displays a blank page. What happens?
+First of all, check that you send nothing to the browser after the PDF (not even a space or a +carriage return). You can put an exit statement just after the call to the Output() method to +be sure. If it still doesn't work, it means you're a victim of the "blank page syndrome". IE +used in conjunction with the Acrobat plug-in suffers from many bugs. To avoid these problems +in a reliable manner, two main techniques exist: +
+
+- Disable the plug-in and use Acrobat as a helper application. To do this, launch Acrobat, go +to the Edit menu, Preferences, Internet, and uncheck "Display PDF in browser". Then, the next +time you load a PDF in IE, it displays the dialog box "Open it" or "Save it to disk". Uncheck +the option "Always ask before opening this type of file" and choose Open. From now on, PDF files +will open automatically in an external Acrobat window. +
+The drawback of the method is that you need to alter the client configuration, which you can do +in an intranet environment but not for the Internet. +
+
+- Use a redirection technique. It consists in generating the PDF in a temporary file on the server +and redirect the client to it. For example, at the end of the script, you can put the following: +
+
```
//Determine a temporary file name in the current directory
+$file = basename(tempnam('.', 'tmp'));
+rename($file, $file.'.pdf');
+$file .= '.pdf';
+//Save PDF to file
+$pdf->Output($file, 'F');
+//Redirect
+header('Location: '.$file);
```
+
+This method turns the dynamic PDF into a static one and avoids all troubles. But you have to do +some cleaning in order to delete the temporary files. For example: +
+
```
function CleanFiles($dir)
+{
+    //Delete temporary files
+    $t = time();
+    $h = opendir($dir);
+    while($file=readdir($h))
+    {
+        if(substr($file,0,3)=='tmp' && substr($file,-4)=='.pdf')
+        {
+            $path = $dir.'/'.$file;
+            if($t-filemtime($path)>3600)
+                @unlink($path);
+        }
+    }
+    closedir($h);
+}
```
+
+This function deletes all files of the form tmp*.pdf older than an hour in the specified +directory. You may call it where you want, for example in the script which generates the PDF. +
+
4. I can't make line breaks work. I put \n in the string printed by MultiCell but it doesn't work.
+You have to enclose your string with double quotes, not single ones. +

5. I try to display a variable in the Header method but nothing prints.

+You have to use the global keyword to access global variables, for example: +

function Header()
+{
+    global $title;
+
+    $this->SetFont('Arial', 'B', 15);
+    $this->Cell(0, 10, $title, 1, 1, 'C');
+}
+
+$title = 'My title';

+Alternatively, you can use an object property: +

function Header()
+{
+    $this->SetFont('Arial', 'B', 15);
+    $this->Cell(0, 10, $this->title, 1, 1, 'C');
+}
+
+$pdf->title = 'My title';

+
6. I defined the Header and Footer methods in my PDF class but nothing appears.
+You have to create an object from the PDF class, not FPDF: +
+
```
$pdf = new PDF();
```
+
+
+
7. Accented characters are replaced by some strange characters like é.
+Don't use UTF-8 encoding. Standard FPDF fonts use ISO-8859-1 or Windows-1252. +It is possible to perform a conversion to ISO-8859-1 with utf8_decode(): +
+
```
$str = utf8_decode($str);
```
+
+But some characters such as Euro won't be translated correctly. If the iconv extension is available, the +right way to do it is the following: +
+
```
$str = iconv('UTF-8', 'windows-1252', $str);
```
+
+
+
8. I try to display the Euro symbol but it doesn't work.
+The standard fonts have the Euro character at position 128. You can define a constant like this +for convenience: +
+
```
define('EURO', chr(128));
```
+
+
+
9. I get the following error when I try to generate a PDF: Some data has already been output, can't send PDF file
+You must send nothing to the browser except the PDF itself: no HTML, no space, no carriage return. A common +case is having extra blank at the end of an included script file.
+If you can't figure out where the problem comes from, this other message appearing just before can help you:
+
+Warning: Cannot modify header information - headers already sent by (output started at script.php:X)
+
+It means that script.php outputs something at line X. Go to this line and fix it. +In case the message doesn't show, first check that you didn't disable warnings, then add this at the very +beginning of your script: +
+
```
ob_end_clean();
```
+
+If you still don't see it, disable zlib.output_compression in your php.ini and it should appear. +
+
10. I draw a frame with very precise dimensions, but when printed I notice some differences.
+To respect dimensions, select "None" for the Page Scaling setting instead of "Shrink to Printable Area" in the print dialog box. +
+
11. I'd like to use the whole surface of the page, but when printed I always have some margins. How can I get rid of them?
+Printers have physical margins (different depending on the models); it is therefore impossible to remove +them and print on the whole surface of the paper. +
+
12. How can I put a background in my PDF?
+For a picture, call Image() in the Header() method, before any other output. To set a background color, use Rect(). +

13. How can I set a specific header or footer on the first page?

+Simply test the page number: +

function Header()
+{
+    if($this->PageNo()==1)
+    {
+        //First page
+        ...
+    }
+    else
+    {
+        //Other pages
+        ...
+    }
+}

+
14. I'd like to use extensions provided by different scripts. How can I combine them?
+Use an inheritance chain. If you have two classes, say A in a.php: +
+
```
require('fpdf.php');
+
+class A extends FPDF
+{
+...
+}
```
+
+and B in b.php: +
+
```
require('fpdf.php');
+
+class B extends FPDF
+{
+...
+}
```
+
+then make B extend A: +
+
```
require('a.php');
+
+class B extends A
+{
+...
+}
```
+
+and make your own class extend B: +
+
```
require('b.php');
+
+class PDF extends B
+{
+...
+}
+
+$pdf = new PDF();
```
+
+

15. How can I send the PDF by email?

+As any other file, but an easy way is to use PHPMailer and +its in-memory attachment: +

$mail = new PHPMailer();
+...
+$doc = $pdf->Output('', 'S');
+$mail->AddStringAttachment($doc, 'doc.pdf', 'base64', 'application/pdf');
+$mail->Send();

+
16. What's the limit of the file sizes I can generate with FPDF?
+There is no particular limit. There are some constraints, however: +
+
+- The maximum memory size allocated to PHP scripts is usually 8MB. For very big documents, +especially with images, this limit may be reached (the file being built into memory). The +parameter is configured in the php.ini file. +
+
+- The maximum execution time allocated defaults to 30 seconds. This limit can of course be easily +reached. It is configured in php.ini and may be altered dynamically with set_time_limit(). +
+
+- Browsers generally have a 5 minute time-out. If you send the PDF directly to the browser and +reach the limit, it will be lost. It is therefore advised for very big documents to +generate them in a file, and to send some data to the browser from time to time (with a call +to flush() to force the output). When the document is finished, you can send a redirection to +it or create a link. +
+Remark: even if the browser times out, the script may continue to run on the server. +
+
17. Can I modify a PDF with FPDF?
+It is possible to import pages from an existing PDF document thanks to the FPDI extension:
+
+http://www.setasign.de/products/pdf-php-solutions/fpdi/
+
+You can then add some content to them. +
+
18. I'd like to make a search engine in PHP and index PDF files. Can I do it with FPDF?
+No. But a GPL C utility does exist, pdftotext, which is able to extract the textual content from +a PDF. It is provided with the Xpdf package:
+
+http://www.foolabs.com/xpdf/ +
+
19. Can I convert an HTML page to PDF with FPDF?
+Not real-world pages. But a GPL C utility does exist, htmldoc, which allows to do it and gives good results:
+
+http://www.htmldoc.org +
+
20. Can I concatenate PDF files with FPDF?
+Not directly, but it is possible to use FPDI +to perform this task. Some free command-line tools also exist:
+
+mbtPdfAsm
+pdftk +

+ + -- cgit