PHP realizes the generation and download of PDF files

With the continuous upgrading of modern technology, various types of file formats are constantly being developed. Among them, the PDF (Portable Document Format) file format has become well-known and widely used by many users due to its convenience and cross-platform features. One of the file formats. This article will introduce the generation and downloading of PDF files in PHP language.

1. What is a PDF file

PDF file is a cross-platform, portable, printable document format developed by Adobe. Taking advantage of the PDF file format, the content of the PDF file remains unchanged. Users can view and print documents on any device (whether it is a computer, mobile phone or tablet), while ensuring that there will be no deviation in the layout and format of the document.

The generation and downloading of PDF files can be widely used in the business of various enterprises, such as e-commerce orders, sales reports, contract documents, etc. There are also many technologies for realizing PDF file operations, among which PHP language is the application A language of extremely broad scope. The following will introduce how to use PHP language to generate and download PDF files.

2. Use PHP to generate PDF files

In the PHP language, you can generate PDF files by using a third-party library. The most popular PDF generation library is FPDF (Free PDF), which Can be used to generate PDF files containing text and images. The following are the basic steps to use the FPDF library to generate simple PDF files:

1. Download and install the FPDF library: You can download the latest version of the FPDF library from the official website https://www.fpdf.org/, and install Unzip it into a PHP project.

2. Set the PDF document object: use the following code to set the PDF document object:

$pdf = new FPDF();

3. Add a PDF page: use the following code Add PDF page:

$pdf->AddPage();

4. Set PDF page properties: You can use the following code to set the properties of PDF page:

$pdf ->SetTitle("My First PDF");

$pdf->SetAuthor("John Doe");

$pdf->SetSubject("Test file");

$pdf->SetKeywords("PDF, PHP, FPDF");

5. Add text and images to PDF pages: You can use the following code to add text and images to PDF pages:

$pdf->SetFont('Arial','B',16);

$pdf->Cell(40,10,'Hello World!');

$pdf->Image('image.png',10,30,30);

6. Output PDF file: Finally, use the following code to output the PDF file:

$pdf->Output('MyPDF.pdf','D');

The above are the basic steps for using the FPDF library to generate PDF files. FPDF provides a wealth of API functions that can be used to generate various The format and style of PDF files basically meet most PDF generation needs.

3. Use PHP to download PDF files

To download PDF files, you can use PHP’s file transfer function header(). The header() function will not output any html code or text content. Instead, HTTP header information is sent to the client browser to control the browser.

The following is the basic PDF file download code:

$file_name = "MyPDF.pdf";

$file_url = "http://www.example.com/ MyPDF.pdf";

header("Content-type:application/pdf");

header("Content-Disposition:attachment;filename=$file_name");

readfile($file_url);

In the code, the PDF file name and file path to be downloaded are first defined, and then the header() function is used to send the HTTP header information, in which Content-type is set to application/pdf , indicating that the PDF file is sent, Content-Disposition is set to attachment, and the file name is passed in, so that the browser uses the file name when downloading the file.

Finally, use the readfile() function to read the file content and output it to the browser to implement the PDF file download operation.

4. Notes

When using PHP language to generate and download PDF files, you need to pay attention to the following points:

1. Make sure that the FPDF library has been correctly installed. , and its script file has been introduced into the PHP script.

2. When generating PDF files, using excessively large fonts, images, tables and other elements may cause the PDF file to expand in size, increase transmission time and occupy space.

3. When outputting the content of a PDF file, you need to pay attention to setting the header information to ensure that the file can be downloaded correctly, otherwise unexpected errors will occur.

4. Summary

PDF file is a convenient, portable, printable document format that is widely used in a variety of scenarios. Using PHP language, you can generate and download PDF files through the third-party library FPDF. When implementing the operation, you need to pay attention to issues such as PDF file size and header information settings to ensure that the generated PDF file can be downloaded and viewed normally.

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