Need javascript to checkbox in PDF form based upon value not null in another text field

[ds_mstar]

Please help with javscript in text field custom calculation field in Adobe Acrobat Pro DC fillable form.

I have a NO and YES checkbox, with a TextField that will be NULL or have a text value.

1. I want a check in the checkbox NO, if the text field is NULL
2. I want a check in the checkbox YES, if the text field is NOT NULL

Thanks in Advance!

I saw this script on a user board below, but receive a syntax error at line 7, but don't know how to fix.

if((String(event.value) == "") || (event.value == ""))
{
this.getField("LB8No").value = "Off";
this.getField("LB8Yes").value = "Off";
}
else if(event.value <> "")
{
this.getField("LB8No").value = "Off";
this.getField("LB8Yes").value = "On";
}

[JR Boulay · Accepted solution]

if (event.value.toString().length > 0)

{this.getField("CHECKBOX").value = "yes";}
else

{this.getField("CHECKBOX").value = "no";}

Be sure that the 2 checkboxes have exactly the same name and a different export value ("yes" and "no" in this sample).

Beware that JavaScript is case sensitive ("Yes" is not "yes").

[ds_mstar]

@JR_Boulay - Thanks for your prompt reply! I'll try and confirm on this post if it worked out.

[ds_mstar]

@JR_Boulay - That worked! Thanks so much for your help!

[ds_mstar]

@JR_Boulay, I have a follow up question....the script works when I manually enter data in the "textfield" it checks or unchecks the appropriate box.

However, it does not automatically check the boxes when the "textfield" is auto-populated with a data function from the datadase that pre-populates the text field. The text field is a string of alphanumeric chars. In this case does "(event.value.toString().length > 0)" need to be changed to something else to recognize that the field is not null because the form's textfield was pre-populated with mapped data to database field.  Thanks for your help!

[stephenh22275384]

Thank you JR,

I modified your answer to help me as a solution for my problem which was to have check boxes checked or not checked, based on a text field being not null.  This is an Acrobat X form.

My script is below and is added as a custom calculation:

if (event.value=="")
{this.getField("DealerLicNumber").value = "No";}
else
{this.getField("DealerLicNumber").value = "Yes";}

If my text field is not blank, then two Yes checkboxes will be checked.  If text field is blank, then two No checkboxes will be checked.  Thanks to your answer to ds_mstar's question, this now works in my form.

If I manually check or uncheck one of the boxes, Javascript Debugger pops error messages.  Is there a way to account for this in the JavaScript?

[KrunalLathiya]

To loosely check if the variable is null, use a double equality operator(==). The double equality operator can not tell the difference between null and undefined, so it counts as same. So if you want to strict check, then don't use a double equality operator. It will lead to misconclusion.

The best way to check for a “null” value in JavaScript is to do a strict equality comparison of the value against the null keyword or Object.is() method and pass both values.

To check null in JavaScript, use triple equals operator(===) or Object.is() method. To find the difference between null and undefined, use the triple equality operator or Object.is() method.

If a checkbox is unchecked, it doesn't get sent, so setting it's value to 0 if it isn't checked isn't going to help - it will always return NULL.

There are two ways to fix this easily:

1) Assume a NULL in the PHP params means the checkbox is unchecked. If the checkbox doesn't always exist on the page, this could be problematic. By the sounds of it, there is a variable number of checkboxes, so this probably won't work.

2) Add a hidden input that has the same name as the checkbox with the value of 0 BEFORE the checkbox. If the checkbox is unchecked, the hidden field value will be used, if it is checked the checkbox value will be used.

[JR Boulay]

"However, it does not automatically check the boxes when the "textfield" is auto-populated with a data function from the datadase that pre-populates the text field."

In this case you should place the script as a "Validation" script instead of a "Calculation" script.

[JR Boulay]

"If a checkbox is unchecked, it doesn't get sent, so setting it's value to 0 if it isn't checked isn't going to help - it will always return NULL."

If a checkbox or a group of radio-buttons is not checked the returned value is "Off".

"null" means that the targeted form field does not exist.