Situation:
(Large) PDFs are stored on an iOS device
The PDFs are encrypted using a Rijndahl algorithm
When tapping one of the PDFs, it gets decrypted and afterwards viewed using a PDF viewer I implemented. The viewer is using the Core Graphics functionality to render the document page by page.
Issue:
With the documents being large enough, encrytion will take a while.
Viewing can only be started after the whole document has been decrypted into a temp file.
I'm wondering, if there is a way to...
Pass some kind of stream to CGPDFDocument instead of a file URL
Or any other alternative to be able to view as many pages as possible whil decrpytion is continued in the background?
If you cannot split your original PDF files down to single pages (as I suspect), then the following approach should work:
A: When still decrypting:
try to open the PDF document as you already do;
try accessing the document page you are interested in;
if it does not fail, render the page;
if it fails, then you know that page is not available yet (while decrypting);
while decrypting, release the pdf document each time you try to get a new page.
B: when decryption is done: do as you are already doing.
Please note that this is just a suggestion, I have not tried this while decrypting a document, but if point 1. does not fail, then this should work.
Related
I would like to ask the following if possible. We have a client that wants a separate pdf document, embedded in a main pdf document and opens when you click it. Like the function in MS Word where you can attach another Word document inside a Word document (Word-ception, lol) and you can still open it.
I've tried it in Acrobat Pro with the Attachment and Link tools. Another option was to put the link document in an ftp server for accessibility. but our client really wants this functionality. Is this possible in Indesign?
Thank you!
Using Word as your example vehicle there are several ways to link 2 documents.
One is an appendix to the other, in PDF terms is a merge or binding but its one flowing document with separate sequential sections/chapters.
Another way is to link to an external file, in PDF terms a hyperlink to a relative second file, which can be locally folder relative or a web absolute reference. You have tried that.
In Word we can add objects internally with icons, in PDF that can be an annotation comment attachment to save externally and action accordingly. You also seem to discount that approach.
Finally PDF offers an Adobe Specific Structure where multiple PDFs attachments can be imbedded in an overall PDF wrapper. These are called Portfolios and not! to be confused with their portfolio service
They are unpopular since in a browser without Adobe Reader they should only offer the cover page.
Whilst in securer offline readers the files may well be shown as attachments that you need to save or independently open to view them.
Only some non Acrobat viewers may view them as a collection. And in the past that required runing insecure SWFlash, But I understand that has changed ?
Here is how the 3 internal PDF files seen above were shown in older Acrobat 9.
Possibly the best experience is using Foxit Reader
I've built my own .PDF carefully following Adobe PDF specifications. macOS has Preview and that opens and displays the PDF document properly, but Acrobat Reader reports an error, not specified, and does not display the document.
If I open it with Preview and export it from there as another PDF, the result is shown properly by both Preview and Acrobat Reader.
The Preview version is somewhat inexplicably complicated and I cannot determine what difference was done by Preview to allow Acrobat to handle it.
Nor have I been able to find software, even from Adobe's site, that will diagnose the problem.
I have attempted many reasonable variations, additions, etc. on my PDF, to no avail.
What's the secret formula to unlock the beast?
In response to the request, here's an abbreviated copy of the PDF file. All the controlling objects are present but I've deleted portions of the streams to spare you the scrolling. There are two fonts on one page which is an amalgam made of two separate source PDFs, one generated by me and the other from a different supplier, hence the preliminary /Contents objects setting up scaling preliminary to each page object.
Well, after placing the sample here, I get a reject message saying there was an error submitting the edit.
I'm going to try again after eliminating all the compression code in the streams and much of the uncompressed formatting code, to save you from all the scrolling.
(PDF code removed as requested. Stay tuned for update.
I created a browser extension that lets you look up words in Wikipedia or Wiktionary without needing to open a new tab ( https://addons.mozilla.org/en-US/firefox/addon/in-page-lookup/ , almost done porting to Chrome). It is very useful when you are doing research and come across a word you don't know or want to know more about. The only thing is, a lot of research content is in PDF format. A long time ago (~2013ish) I had an older version of the app based on the old Firefox add-on framework and that did let iframes show up over pdf documents but this has not been the case for many years. I don't think the extension is even recognized in pdf documents, I get "Error: Could not establish connection. Receiving end does not exist" and there is no extension content script on the pdf page. So, my question is, is it possible to put an iframe over a pdf document? Do I need to work on the background side, and if so, how? Thanks.
We have this big web project where the user can print the html to pdf. We are using dompdf, and have somewhat fixed the long cell issues that cause the pdf to have several blank pages. Now the issue is that the saved pdf, when closing, always asks if the user wants to save changes. I have verified that the pdf has the proper %%EOF, and have checked for object consistency. What else could be causing this problem?
After reading this introduction to pdf I realized that if the pdf was modified, I had to accomodate all the object offsets so that they would point to the object start location.
I've already referred to this SO post. I've been embedding images using an AlternateView for PNG files. Now I'm wondering how to do it with PDFs.
Should it work, for the LinkedResource, to just say:
Dim document As New LinkedResource(pdfFilePath, "image/pdf")
I'm just trying to figure out how to get the PDF to be embedded like I could with an image, or is that not possible and I'll have to do it as an attachment?
You can embed images since they can be rendered in place by an email client. PDFs cannot do that, so I'd recommend either having a thumbnail of the PDF that links to your web site with the actual PDF. Or just attach the PDF to the email message.
There are a few options that I know of.
1) Is the simplest way okay? The easiest by far would be to attach the PDF as a normal attachment. Then render the first page of the pdf as an image, embed it in the email and link it to open the PDF if you can. Entourage kind of does this on the Mac.
Alternatively, what I found was the following:
2) FLASHPAPER embedded in HTML displaying a PDF. Adobe has a technology called Flashpaper. It is a flash based file viewer. You can use flashpaper format documents that go into it, or PDFs as the source.
Check out some examples. That's really flash. http://www.adobe.com/products/flashpaper/examples/
Assuming you send an HTML email that will get through (images aren't turned off, etc), you can can embed the Flashpaper viewer right in your HTML code as a normal Flash object.
Most HTML email clients use Internet Explorer Bits, Webkit bits, or Gecko bits to render the html. Flash player is pretty well installed on everything, so it works well. A good example of this is when we open an email and it has video playing in it. It's almost always Flash.
I have had luck doing it this way -- the only thing you'd have to decide is if most of your clients can see this and how much (if any) today's software might block it.
What I ended up doing was a hybrid. 1) Attach it to the email, 2) Embed the Flashpaper viewer. They get it either way.
Flashpaper is available seperately for $75. It has come in handy where the client was not able to install adobe acrobat on each computer and it had to be 100% web based.
I would imagine you should be able to do the same using any language with a little more effort and using something like Flashpaper.
Hope that helps
This is not possible--at least not in a way that will work with many clients. You'll need to just attach the file.
If you have only one client to worry about, it might be possible--but not likely without manually changing settings on each client.
The MIME type of a PDF is "application/pdf" not "image/pdf"