Digital Signature

Ignition
1

Hi Guys

We have put some forms onto ignition, they need an acknowledgement signature, however I can’t seem to find anything in ignition for doing this. I am recording all the form entries to a database and would like to attach a digital signature to it, ideally for cost a hand drawing input box would be good, however if not I am open to ideas.

Thanks in advance

ps (I did find this topic, but the link is broken :frowning: http://forum.inductiveautomation.com/t/anyone-used-digital-signature-pad/10224 )

2

I created a Cloud Template (Designer -> Tools -> Cloud Templates) called the “Drawable Canvas” that extends the paintable canvas and allows you to hand-draw onto an Ignition component.

You could pair this with the system.print.createImage function to turn the drawn signature into a raw image, which you could then store into the DB as a BLOB.

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3

Perfect!! Thank you very much

4

To save others further Googling if they come upon this thread now like I did, Cloud Templates no longer exist and were replaced with Exchange (go to https://inductiveautomation.com/exchange/567/overview to download the Drawable Canvas instead), and to get the data from the image returned using system.print.createImage as a byte array you need to import javax.imageio and java.io ByteArrayOutputStream.

Something like this, where event.source is the Drawable Canvas component, should get you your signature/image as bytes:

from javax.imageio import ImageIO
from java.io import ByteArrayOutputStream

im = system.print.createImage(event.source)

baos = ByteArrayOutputStream()
ImageIO.write(im, “PNG”, baos)
imAsBytes = baos.toByteArray()

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