How to show and edit existing PDF files in ios application

Question

I do not want to create new PDF file,that I had already done but want to show and edit existing pdf file in iOS through code..

Is this possible or not and if possibl

Answer 1

You can use Quartz2D to manipulate your PDF, open them, make transformation and so on.

Check out the official documentation

Update :

Create your pdf context as explained in the documentation, then you just have to write text :

http://developer.apple.com/library/ios/#documentation/graphicsimaging/conceptual/drawingwithquartz2d/dq_text/dq_text.html#//apple_ref/doc/uid/TP30001066-CH213-TPXREF101

Answer 2

I was able to do this by creating a copy of the original PDF and modifying it during the build process.

PS: In my solution I needed to edit the document info of the new PDF, so I used the subject parameter to do this.

In Swift 3

func createPDF(on path: String?, from templateURL: URL?, with subject: String?) {
    guard let newPDFPath = path,
        let pdfURL = templateURL else { return }

    let options = [(kCGPDFContextSubject as String): subject ?? ""] as CFDictionary

    UIGraphicsBeginPDFContextToFile(newPDFPath, .zero, options as? [AnyHashable : Any])

    let templateDocument = CGPDFDocument(pdfURL as CFURL)
    let pageCount = templateDocument?.numberOfPages ?? 0

    for i in 1...pageCount {

        //get bounds of template page
        if let templatePage = templateDocument?.page(at: i) {
            let templatePageBounds = templatePage.getBoxRect(.cropBox)

            //create empty page with corresponding bounds in new document
            UIGraphicsBeginPDFPageWithInfo(templatePageBounds, nil)
            let context = UIGraphicsGetCurrentContext()

            //flip context due to different origins
            context?.translateBy(x: 0.0, y: templatePageBounds.height)
            context?.scaleBy(x: 1.0, y: -1.0)

            //copy content of template page on the corresponding page in new file
            context?.drawPDFPage(templatePage)

            //flip context back
            context?.translateBy(x: 0.0, y: templatePageBounds.height)
            context?.scaleBy(x: 1.0, y: -1.0)


            // -->>>>  Do your change here  <<<<--
            /* Here you can do any drawings */

        }
    }
    UIGraphicsEndPDFContext()
}

Answer 3

I know its too late for this question, however I'd like to add my solution.

I am using UIGraphicsBeginPDFContextToFile to generate a PDF file. I've created a class called PDFCreator from base class UIViewController, in that I have two functions like this:

- (void) beginContextWithFile:(NSString *)filename
{
    pageSize = CGSizeMake(1024, 1424);

    UIGraphicsBeginPDFContextToFile(filename, CGRectZero, nil);

    UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, pageSize.width, pageSize.height), nil);

    [self createInitialPart];
}

- (void) endContext
{
    UIGraphicsEndPDFContext();
}

I've created an object of this class in the app delegate file, as it will retain the object until the app terminates (as was my requirement).

Initially, I am calling beginContextWithFile: and it will create a pdf file in the document directory along with data I am adding through a call to the createInitialPart method.

At some point later I need to update that file, so I have another method named secondPart though I called it for some more data to append to that file.

Once I fill I've done with the creation, I need to call endContext of PDFCreator class, that will complete the pdf generation and yes, I will have the updated file.

This is little tricky and I didn't perform any memory checks though I had the requirement, I found the solution :)