CFPDF musings

Since I've been heavily modifying PDFs lately I've discovered that CFPDF has got to be the most under-documented tag in Coldfusion. Shame really, you would think a company that does so much with PDFs would have the most top notch documentation for the manipulation functions they include in their own server application.

The good news is that it seems everything we would want to do calling in java objects and using the iText library can be accomplished with this tag, the bad news is that there is very little help as to how.

So here are some things I've learned lately that may help y'all out.

1. If you have a process that may generate multiple PDFs and you want to join them together with the merge action, there seems to be a bug that requires you to specify the pages argument if there is only one pdf in your source list. The live docs say that pages is optional, but the server throws an error if it's not included in this instance.
2. I guess this is standard when dealing with print, but it makes no sense to me. When you use the watermark action your origin is actually the bottom left instead of the top left. So when it comes to positioning things, you have to measure the height of the watermark, and calculate how much to adjust the y axis in the negative. By negative I mean that you give it a positive number to move the water mark upwards, so the opposite of how you might set a div with position:absolute
3. When you use the getinfo action it will give you a height and width, but in points instead of pixels, so be ready to do some .75 and 1.25 conversions to properly deal with pixels to points and back. And since I just mentioned watermark positioning, you position in pixels, even though the getinfo is in points, so keep that in mind when you are attempting to line things up. Sub point to this, if you have a landscape page it will still say it's 8.5x11 inches instead of 11x8.5, but also that it has a rotation of 90, so remember to take that into account when determining what your height and width actually are.
4. While cfdocument does great converting HTML to PDF, there isn't really a simple way to window one PDF inside another generated with your HTML code, but using the watermark action does a pretty good job of layering one PDF into another, so you can generate your outer PDF then use watermark to layer your inner PDF in that border. You can do this with multi-page PDFs by generating your border, then looping through the PDF you want surrounded by that border, then use the watermark feature iterating through the pages. At the end you merge them all together and you have a nifty new PDF windowed in your custom border. I also used the transform action to scale down the inner PDF to fit within my border so my output was still an 8.5x11 inch page.

That's all I have come up with so far, I'll add more as I come across them.