Signature control - how can we determine it's a blank graphic

[workaholic06]

We tried using the .signatureIsEmpty() javascript function in the ExecuteServerSideAction action script

we added an alert("Empty"); but it's not seeing it as empty.

Does anyone know how to identify that the 'signature' capture image is empty, so we can set a flag, or run some logic so we know the user didn't do anything?

We understand that a single dot in the image would not be considered empty, but we want to at least capture the empty condition

[cptutrecht]

Maybe another approach: store in a variable an empty graphic you created yourself. Than compare the submitted value of the graphic with that?

[workaholic06]

I actually thought of that.. but since they already have the signatureIsEmpty() function... i thought i'd try that first..

Thanks for your reply! it is definitely going to be the approach I take if we can't figure out the function.

[madtowng]

This seems to be another example of how sharing the actual code of what you're doing can aid
in finding the proper solution.
Are you testing using the same method shown in the documentation ? https://documentation.alphasoftware....empty%20method

[kingcarol]

The person who started this post is helping me with this. I am on build 6655-5457. I have just tried both of the following and the value that gets put into label1 is false whether there is a signature showing in the capture box or not. I clear the box, then commit, then submit, and get false result, when I would expect a true result. The code is in the After Save Succeeded Javascript client side event in the action scripting Save Submitted Data To Tables called by server side event afterDialogValidate, and the Signature Capture control is named VENDOR_SIGNATURE.

var flagEmpty = {dialog.object}.signatureIsEmpty('VENDOR_SIGNATURE',0);
{dialog.object}.setValue('label1',flagEmpty);

var flagEmpty = {dialog.object}.signatureIsEmpty('VENDOR_SIGNATURE');
{dialog.object}.setValue('label1',flagEmpty);

[kingcarol]

I just saw this post in this thread by DavidK, so I am going to go play with this concept:
https://forum.alphasoftware.com/foru...gnatureisempty

"You'd put this Javascript code anywhere you want to test your Signature Capture control.

Code:
var sigEmpty = {dialog.Object}.signatureIsEmpty('SIG2',600);
Where 'SIG2' is the variable name of your control and sigEmpty will be either true or false.
Make sure your variable name is upper case. In this case I'm testing to see if SIG2 < 600 and if so, then it's empty... and so sigEmpty will be true

The 2nd param would be dependant on where you're running the component. E.g. In Chrome is seems like an empty Signature has a length of 2518. Whereas in Firefox an empty Signature is 542. The browser in an iOS device reports 2010. Mileage may vary.

So... you need to be aware of where you're running."

[kingcarol]

So, the above did not work. I tried the following in Firefox, while the signature capture box was empty, and still got false put into my label1 control.

var flagEmpty = {dialog.object}.signatureIsEmpty('VENDOR_SIGNATURE',600);
{dialog.object}.setValue('label1',flagEmpty);

[kingcarol]

Just to make it clearer, I put a button on my signature capture ux, and onClick of the button has inline javascript as follows, and always returns that the signature is not empty, no matter if it is or not.

var flagEmpty = {dialog.object}.signatureIsEmpty('VENDOR_SIGNATURE',600);
if (flagEmpty) {
alert("Signature is empty.");
} else {
alert("Signature is not empty.");
}

[kingcarol]

I just went into the database and manually emptied the VENDOR_SIGNATURE OLE field and then used sql to get the value in that field in xbasic and then tested the result with:

if rs.DataIsNull(1) = .t.,

and It DOES give me a true result.

[iRadiate]

Just to make it clearer, I put a button on my signature capture ux, and onClick of the button has inline javascript as follows, and always returns that the signature is not empty, no matter if it is or not.

var flagEmpty = {dialog.object}.signatureIsEmpty('VENDOR_SIGNATURE',600);
if (flagEmpty) {
alert("Signature is empty.");
} else {
alert("Signature is not empty.");
}

I didn't know this but there is a sister function called {dialog.Object}.inkIsEmpty(UXControlName);

I don't use the signature capture control, rather I use the ink control for my signatures, so I put the same code you have on your signature ux into a test button on my ux and it works.
So, it might be worth sending a report to Alpha about the signatureIsEmpty function. Not sure why the inkIsEmpty function works but not the signatureIsEmpty one?

javascript.jpg

result.jpg

[iRadiate]

Here's a quick demo of the inkIsEmpty function .. https://www.screencast.com/t/RhtVws842G

[kingcarol]

On the ink control, does it think its empty after signing, submitting, the clearing it, then submitting?

[iRadiate]

Hmm, I'm not sure I can test that Carol since my use is not set up that way. I have a blank signature field when the user opens the UX. When they click the checkbox it reads in the signature based on their login info and populates the signature field.
When the UX is submitted it is closed so the next form that is opened will be blank again.

[peteconway]

I would ask AA about this, I don't use either control but did test them today, what's going on with the control is ambiguous.
When is it ever empty? - Just send a note to Selwyn for assistance on it, send your test case.
Pete

signatureIsEmpty Method


Syntax

{dialog.Object}.signatureIsEmpty(UXControlName [, length]);

Arguments
UXControlNameID of the Signature Control
lengthThe "length" to compare the base64 encoded string to determine whether or not the signature is empty.

Description

Returns value indiciating whether or not the Signature control is empty.

Discussion

Returns true if a signature control is empty (has not been signed). The base64 encoded signature is compared against a 'length' parameter to determine if the control is empty.

If you do not pass in a length parameter, a default parameter value (appropriate for the type of browser you are using) is used.

Note that even if a signature control has not been signed, the base64 encoded value in the control is not be empty.

Example

var flagEmpty = {dialog.object}.signatureIsEmpty('signature1');

[madtowng]

I can't help but wonder if the trick is to grab the length of the control while it's "empty", then compare that length to the length of the control after it's been submitted.