### Installing CombinePDF Gem

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This snippet provides the command to install the CombinePDF Ruby gem using the standard RubyGems package manager.

```Ruby
gem install combine_pdf
```

--------------------------------

### Rendering PDF to Memory for Web Download (Rails) - Ruby

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This example shows how to render a CombinePDF object into a string in memory, which can then be sent as a file download in a Ruby on Rails application controller action.

```Ruby
# in a controller action
send_data combined_file.to_pdf, filename: "combined.pdf", type: "application/pdf"
```

--------------------------------

### Stamping/Watermarking PDF Pages with CombinePDF

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This example demonstrates how to add content, such as a company logo, from one PDF file onto every page of another existing PDF document, effectively stamping or watermarking them.

```Ruby
company_logo = CombinePDF.load("company_logo.pdf").pages[0]
pdf = CombinePDF.load "content_file.pdf"
pdf.pages.each {|page| page << company_logo} # notice the << operator is on a page and not a PDF object.
pdf.save "content_with_logo.pdf"
```

--------------------------------

### Merging Multiple PDF Files with CombinePDF (Basic)

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This example demonstrates the fundamental way to combine two existing PDF files into a new one. It loads each PDF and appends them to a new CombinePDF object before saving the result.

```Ruby
pdf = CombinePDF.new
pdf << CombinePDF.load("file1.pdf") # one way to combine, very fast.
pdf << CombinePDF.load("file2.pdf")
pdf.save "combined.pdf"
```

--------------------------------

### Advanced Page Numbering with Custom Formatting and Ranges - Ruby

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This comprehensive example illustrates how to apply advanced page numbering, including custom formats, multiple locations, specific page ranges, and styling options like box color, border, radius, and opacity.

```Ruby
# number first 3 pages as "a", "b", "c"
pdf.number_pages(number_format: " %s ",
                 location: [:top, :bottom, :top_left, :top_right, :bottom_left, :bottom_right],
                 start_at: "a",
                 page_range: (0..2),
                 box_color: [0.8,0.8,0.8],
                 border_color: [0.4, 0.4, 0.4],
                 border_width: 1,
                 box_radius: 6,
                 opacity: 0.75)
# number the rest of the pages as 4, 5, ... etc'
pdf.number_pages(number_format: " %s ",
                 location: [:top, :bottom, :top_left, :top_right, :bottom_left, :bottom_right],
                 start_at: 4,
                 page_range: (3..-1),
                 box_color: [0.8,0.8,0.8],
                 border_color: [0.4, 0.4, 0.4],
                 border_width: 1,
                 box_radius: 6,
                 opacity: 0.75)
```

--------------------------------

### Parsing PDF Data from Memory (Prawn Integration) - Ruby

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This example illustrates how to parse PDF data directly from a string in memory, which is particularly useful for integrating CombinePDF with other PDF generation libraries like Prawn.

```Ruby
pdf_data = prawn_pdf_document.render # Import PDF data from Prawn
pdf = CombinePDF.parse(pdf_data)
```

--------------------------------

### Adding Page Numbers to Bottom Right with CombinePDF

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This example shows how to customize the placement of page numbers, specifically positioning them at the bottom right of each page in the PDF document.

```Ruby
pdf.number_pages(location: [:bottom_right])
```

--------------------------------

### Loading PDFs with Optional Content (Ruby)

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This Ruby snippet demonstrates how to load PDF files using the `CombinePDF` library, specifically allowing for optional content sections. It initializes a new PDF object, loads a primary PDF file, and then iterates through a collection of attachments, loading each one while explicitly setting `allow_optional_content` to `true` to prevent exceptions for files with such sections.

```Ruby
new_pdf = CombinePDF.new
new_pdf << CombinePDF.load(pdf_file, allow_optional_content: true)
attachments.each { |att| new_pdf << CombinePDF.load(att, allow_optional_content: true) }
```

--------------------------------

### Configuring HTTP Response for PDF Download (Ruby DSL)

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This snippet defines an HTTP response within a web application's path block, likely using a Ruby-based DSL. It sets the HTTP status to 200 (OK), sends the combined PDF file's binary data as the response body, and specifies the 'Content-Type' header as 'application/pdf' to prompt a download in the browser.

```Ruby
status 200
body combined_file.to_pdf
headers 'content-type' => "application/pdf"
```

--------------------------------

### Loading PDF Data from File with CombinePDF

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This code shows the straightforward method for loading an existing PDF document directly from the file system into a CombinePDF object for further manipulation.

```Ruby
pdf = CombinePDF.load("file.pdf")
```

--------------------------------

### Overlaying Compressed PDF Pages with CombinePDF

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This snippet provides an alternative method for overlaying pages, specifically useful for compressed data that might not be editable, by iterating through pages with the `pdf.pages(nil, false)` option.

```Ruby
pdf.pages(nil, false).each {|page| page << stamp_page}
```

--------------------------------

### Adding Basic Page Numbers to a PDF with CombinePDF

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This code demonstrates the simplest way to add sequential page numbers to all pages of a loaded PDF document using the `number_pages` method.

```Ruby
pdf = CombinePDF.load "file_to_number.pdf"
pdf.number_pages
pdf.save "file_with_numbering.pdf"
```

--------------------------------

### Merging Odd or Even Pages from a PDF with CombinePDF

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This code illustrates how to selectively extract and combine only the odd or even pages from an existing PDF file into a new PDF document, demonstrating page-level manipulation.

```Ruby
pdf = CombinePDF.new
i = 0
CombinePDF.load("file.pdf").pages.each do |page|
  i += 1
  pdf << page if i.even?
end
pdf.save "even_pages.pdf"
```

--------------------------------

### Merging Multiple PDF Files with CombinePDF (One-Liner)

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This snippet shows a more concise approach to merge multiple PDF files by chaining the `<<` operator directly on the loaded PDF objects before saving the final combined document.

```Ruby
(CombinePDF.load("file1.pdf") << CombinePDF.load("file2.pdf") << CombinePDF.load("file3.pdf")).save("combined.pdf")
```

--------------------------------

### Parsing PDF Data from Remote URL with CombinePDF

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This snippet demonstrates how to fetch PDF data from a remote URL using Ruby's `Net::HTTP` and then parse it directly into a CombinePDF object, bypassing the need for temporary files.

```Ruby
require 'combine_pdf'
require 'net/http'

url = "https://example.com/my.pdf"
pdf = CombinePDF.parse Net::HTTP.get_response(URI.parse(url)).body
```

--------------------------------

### Customizing Page Number Font Size with CombinePDF

Source: https://github.com/boazsegev/combine_pdf/blob/master/README.md

This snippet demonstrates how to easily adjust the font size of the page numbers when applying them to a PDF document, allowing for better visual integration.

```Ruby
pdf.number_pages(number_format: " %s ", location: :bottom_right, font_size: 44)
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.