Signature capture in SQL table

[ddprlewis]

This is a little complicated. I have a VFP application tied to SQL Server data that we are extending to mobile devices using Alpha Anywhere. One of the functions we need to do is to be able to capture a signature on delivery of an order and then be able to produce this signature on an invoice (after order is shipped) which is generated out of the VFP application, so it is a standard VFP report form.

So, my questions are (plus a few at the bottom):
1. What method should I use for the signature capture?
2. What file type should the data be stored in?
3. How can I get that to display on the invoice?

It looks like the signature control stores as a PNG image, which VFP can't directly read.
The ink control signature is stored in an ASCII format, which looks promising, but is there some method of converting that on the fly into an image that I can then use?
Is there some type of COM control or something that will read that into an image?

I'm assuming that this is possible to do, but I am just not seeing the forest through the trees at this point, so any pointers would be appreciated.

[lvasic]

Re: Signature capture in SQL table

I use the ink control and on an iPad. I store it in a varchar(MAX) on SQL. On the report, I use the Override type of "Ink Image".

It is all working well.

[Davidk]

Re: Signature capture in SQL table

Just for clarification... could you elaborate on exactly what control you're using for a signature? There are 4 controls in Alpha that can be used for Signatures.

Yes... the SignatureCapture Control stores the signature as a PNG... Blob in SQL.
The Ink Control - its format - is a nasty concoction of Alpha's... proprietary... very unfortunate as it's creator, and Alpha, have no interest in doing anything with it... no interest in detailing or exposing its format. It looks like this... right? #A5Ink version 1.0 settings %json% {"page":{"width":5,"height":3,"unit":"in

I've asked, for years, that its format be explained so that we could do things like draw arrows, circles, anything... but... nothing. Too bad.

Does VFP understand base64 image strings? If so, then you could convert the PNG image to base64 and store that in another field. You could do this either on the Client-Side with Javascript or Server-Side with XBasic... or even within SQL Server... on a Trigger.

If you really want to use the Ink Control... then XBasic has this function... a5_ink_to_png. Once in a format the world understands... you can convert it to something else.

https://www.alphasoftware.com/docume...20Function.xml

[ddprlewis]

Re: Signature capture in SQL table

David,

Thanks for responding. I haven't determined what control to use at this point as I am trying to figure out what the best way to make it work is in our environment.

But, I went with your information and came up with a workable solution for either the Signature Capture control or the Ink control using a server side call out in the afterDialogValidate to save the file in a server shared folder that is globally accessible. I was able to then use that information to generate it onto a Visual Foxpro report form. So, I have a proof of concept and that is what I was trying for. I wouldn't have been able to do it without the information you provides, so it is greatly appreciated. I'm still not sure which control should be used, but the method will work for either of them using either the png_to_bitmap if working with the Signature Capture control or the a5_ink_to_png and then the png_to_bitmap if working with the Ink control.

Do you have any pros and cons with which one you consider to be better? I did notice that with the a5_ink_to_png, I could control the size as well and playing around with that allowed me to get a good file size that was still excellent when printed, so I may stay with that, but if there is a legitimate reason to not work with that, I would like to know for the long run.

Thanks again.

[Davidk]

Re: Signature capture in SQL table

I think either would be fine. I don't know why Alpha would introduce another format... but there you go. Sometimes I think it's a process of "we can do it, so we will"... instead of "we can do it, but should we". Seems like a bit of a rogue move... but there you go.

If they'd document it that'd be nice, but requests are falling on deaf ears.