From 3864019c040b88add6a3e668c8f960a5743b5521 Mon Sep 17 00:00:00 2001 From: Saketh1499 Date: Thu, 25 Feb 2021 11:12:35 +0530 Subject: Generating certificates for completed projects --- pdf/fpdf/FAQ.htm | 272 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 272 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..f41ad8a --- /dev/null +++ b/pdf/fpdf/FAQ.htm @@ -0,0 +1,272 @@ + + + + +FAQ + + + + +

FAQ

1. What's exactly the license of FPDF? Are there any usage restrictions?
2. I get the following error when I try to generate a PDF: Some data has already been output, can't send PDF file
3. Accented letters are replaced with some strange characters like é.
4. I try to display the Euro symbol but it doesn't work.
5. I try to display a variable in the Header method but nothing prints.
6. I have defined the Header and Footer methods in my PDF class but nothing shows.
7. I can't make line breaks work. I put \n in the string printed by MultiCell but it doesn't work.
8. I use jQuery to generate the PDF but it doesn't show.
9. I draw a frame with very precise dimensions, but when printed I notice some differences.
10. 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?
11. How can I put a background in my PDF?
12. How can I set a specific header or footer on the first page?
13. I'd like to use extensions provided by different scripts. How can I combine them?
14. How can I open the PDF in a new tab?
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. 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. +
+
3. Accented letters are replaced with some strange characters like é.
+Don't use UTF-8 with the standard fonts; they expect text encoded in ISO-8859-1 or windows-1252. +You can use utf8_decode() to perform a conversion to ISO-8859-1: +
+
```
$str = utf8_decode($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);
```
+
+In case you need characters outside windows-1252, take a look at tutorial #7 or +tFPDF. +
+
4. 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));
```
+
+

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 have defined the Header and Footer methods in my PDF class but nothing shows.
+You have to create an object from the PDF class, not FPDF: +
+
```
$pdf = new PDF();
```
+
+
+
7. 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. +
+
8. I use jQuery to generate the PDF but it doesn't show.
+Don't use an AJAX request to retrieve the PDF. +
+
9. 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. +
+
10. 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. +
+
11. 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(). +

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

+Just test the page number: +

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

+
13. 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();
```
+
+
+
14. How can I open the PDF in a new tab?
+Just do the same as you would for an HTML page or anything else: add a target="_blank" to your link or form. +

15. How can I send the PDF by email?

+As for 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: +
+
+- There is usually a maximum memory size allocated to PHP scripts. For very big documents, +especially with images, the limit may be reached (the file being built in memory). The +parameter is configured in the php.ini file. +
+
+- The maximum execution time allocated to scripts 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(). +
+
+You can work around the memory limit with this script. +
+
17. Can I modify a PDF with FPDF?
+It's possible to import pages from an existing PDF document thanks to the +FPDI extension. +Then you can 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's provided with the Xpdf package. +
+
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. +
+
20. Can I concatenate PDF files with FPDF?
+Not directly, but it's possible to use FPDI +to perform that task. Some free command-line tools also exist: +pdftk and +mbtPdfAsm. +

+ + -- cgit