Managing PDFs in iOS using PDFKit

Managing PDFs in iOS using PDFKit

PDF (Portable Document Format) is a widely used file format that offers several benefits and is highly useful in various contexts. 

Here are some reasons why PDF is valuable:

Document Preservation: PDF ensures the preservation of the original document's formatting, layout, fonts, and images across different devices and operating systems.

Platform Independence: PDFs can be viewed and accessed on different platforms, including Windows, macOS, Linux, iOS, and Android, using a wide range of software and apps.

Document Security: PDFs support robust encryption and password protection, allowing you to secure sensitive information within the document.

Compact File Size: PDF files are often smaller in size compared to other file formats while maintaining high-quality resolution. This makes them easier to store, transfer, and share, especially when bandwidth or storage space is limited.

Print Consistency: PDFs ensure consistent printing across different printers, ensuring that the document's layout and design remain intact. This is particularly important when sharing documents that need to be printed accurately, such as legal contracts or official forms.

Interactive Elements: PDFs support interactive elements such as hyperlinks, bookmarks, annotations, form fields, and multimedia (audio and video).

Handling PDFs using the PDFKit Framework:

With the introduction of the PDFKit Framework in iOS 11, handling PDF documents is hassle-free.

PDFKit is essentially a software component that enables iOS app developers to incorporate PDF-related features into their applications. It helps in displaying PDF documents, allowing users to read, navigate, and zoom in or out of the content. PDFKit also supports searching for specific text within PDFs, extracting text or images, and adding annotations like text, highlights, or shapes.

Additionally, PDFKit allows developers to generate new PDF documents programmatically, modify existing PDFs by adding or removing pages, merge multiple PDF documents, and apply transformations. It also provides options for printing and sharing PDFs.

Benefits of using the PDFKit framework:

PDFKit is a powerful framework provided by Apple for working with PDF documents in iOS applications. It offers several benefits that make it a popular choice for developers.

PDF Rendering:

PDFKit provides built-in rendering capabilities for displaying PDF documents within your iOS app. You can easily render PDF pages, zoom in and out, and navigate through the document.

Annotations and Form Filling:

PDFKit allows you to add various types of annotations to PDF documents, such as text comments, highlighting, underlining, and more. Additionally, you can fill out interactive PDF forms programmatically.

Text Search:

With PDFKit, you can perform text searches within PDF documents, making it easy to find specific content or keywords. This feature is particularly useful for document management or research-oriented applications.

Thumbnail Generation:

PDFKit enables you to generate thumbnail images of PDF pages. These thumbnails can be used to create a visual representation of the document's content, such as a document preview or thumbnail gallery.

Printing and Sharing:

PDFKit facilitates printing PDF documents directly from your app, allowing users to generate hard copies. It also supports sharing PDFs via various channels, such as email or other apps installed on the device.

Document Manipulation:

PDFKit enables you to manipulate PDF documents programmatically. You can extract pages, merge multiple PDFs, reorder pages, delete or insert pages, and perform other document-related tasks.

Customization and Integration:

PDFKit provides various customization options to match the look and feel of your app. You can customize the appearance of annotations, implement custom views for rendering PDF pages, and integrate PDFKit with other iOS frameworks like Core Data or Core Graphics.

Password Encryption:

PDFKit allows you to encrypt a PDF document with a password. You can set a user password, which is required to open and view the document, and an owner password, which grants additional permissions such as editing or printing.

Let us deep dive into PDFKit and explore its key features, providing code snippets to help you leverage its capabilities in your iOS application.

Core classes of PDFKit Framework:

• PDFView

• PDFPage

• PDFDocument

• PDFSelection

• PDFAnnotation

• PDFThumbnailView

PDFDocument:

An object that loads the PDF Document from a local PDF document or from an URL.

PDFView:

A UIView subclass that is used to display PDF documents.

PDFPage:

An object that represents an individual page within a PDF document. It provides methods and properties to access and manipulate the content, annotations, and properties of a specific page.

PDFSelection:

An object that represents a selection of text or other content within a PDF document. It allows you to work with and manipulate the selected text or content.

PDFAnnotation:

An object that represents an annotation or markup associated with a specific area or location within a PDF document. Annotations are used to add additional information, highlight content, draw shapes, or provide interactive elements within a PDF.

PDFThumbnailView:

An object that provides a visual representation of the pages of a PDF document in the form of thumbnails. It allows users to navigate through the document quickly and provides an overview of the document's content.

Basic Usage of PDF:

To start using PDFKit in your iOS Project, you will need to import the framework and create a PDF Document instance. You can load a PDF file from an URL, a local file, or even generate a PDF dynamically.

Rendering and Displaying PDF Content:

PDFKit offers built-in rendering capabilities to display PDF content in your app. You can add a PDFView to your user interface and load a PDF Document into it. PDFView provides features like zooming, scrolling, and navigation within the PDF.

PDFKit on iOS is capable of handling secured or password-protected PDF documents.

PDView Properties:

We can customize PDFView's display direction and mode using the below properties.  pdfView.displayMode = .twoUpContinuous

pdfView.displayDirection = .horizontal

You can Query PDFView to get the current selection, current page, current document, and current visible pages using the properties.

PDFPage and it’s properties:

PDFPage allows us to query the content of a specific page, the number of characters in a page, the page number, the attributed string, and annotations using its properties.

PDFDocument:

An object that loads the PDF Document from a local PDF document or from an URL and manages the security of the PDF document.

PDFDocument helps us perform the following operations:

• Document display

• Loading and Creating PDFs

• Document Navigation

• Page Manipulation (Adding, removing, rearranging, and extracting pages)

• Document Saving and Exporting

• Security handling

Generating PDFs:

In addition to reading and manipulating existing PDFs. PDFKit enables you to generate PDF documents programmatically. You can create PDFs from scratch, combining various elements like text, images, and annotations, providing a seamless way to generate reports or documents within your app.

Methods and Properties of PDFDocument:

Editing PDF Pages:

Using PDFKit, PDF Pages can be edited but not the contents. You can not directly edit the contents of a PDF document; PDFKit is primarily designed for viewing, rendering, and annotating PDF files.

Annotations and Interactions:

PDFKit allows users to interact with PDF documents by adding annotations, highlighting text, and adding notes. You can programmatically create and manage annotations within the PDF, enabling users to mark up and customize their PDF experience.

Here is an example of annotating a highlight annotation on the selected content.

Other Types of Annotations:

Apart from freeText, there are other types of annotations that help for better interaction.

Here are a few screenshots that help you understand Highlight, Circle, Note, square and StrikeOut annotations.

Text Extraction and Search:

PDFKit provides APIs for extracting text from PDF documents, making it easy to search for specific content within the PDF. You can implement search functionality to locate keywords or phrases within the document and navigate to the corresponding pages.

PDFThumbnailView:

An object that provides a visual representation of the pages of a PDF document in the form of thumbnails. It allows users to navigate through the document quickly and provides an overview of the document's content.

Customization and Advanced Features:

PDFKit offers extensive customization options to tailor the PDF viewing experience to your app’s needs. You can customize the appearance of PDF views, define your own annotation styles and even implement advanced features like digital signatures and document encryption.

Conclusion:

In summary, with the PDFKit framework, iOS developers have a powerful toolset at their disposal to work with PDF documents effortlessly. Whether you need to display, annotate, search, or generate PDFs, PDFKit provides a comprehensive set of features to enhance your app's capabilities. Start exploring PDFKit today and unlock the potential of PDF integration in your iOS applications.

I am confident that this blog post, along with the provided code snippets, gave you a good introduction to PDFKit and its features. Stay tuned for future posts where we dive deeper into specific aspects of PDFKit and share practical examples for leveraging its functionality in real-world iOS app development.