Adobe Acrobat 2017 Javascript is null?

0
votes

In this code:

this.getField("myField").value == null;
this.getField("myField").value === null;
typeof this.getField("myField").value == null;
typeof this.getField("myField").value === null;
this.getField("myField").rawValue === null;
this.getField("myField").formattedValue === "";
this.getField("myField").isNull;
this.getField("myField").isNull == True;

all of the above exchanging 'null' for 'Null', encapsulated 'Null', and 'undefined'.

In each circumstance all I get is:

TypeError: this.getField(...) is null
23:Field:Blur

How do I see if a field is null? I do not want to have default values because not every field on the form needs to be used and should be able to be blank.

2
javascriptadobeacrobat

2 Answers

0
votes

Generally... meaning you used an application rather than a library to create the form... PDF field values will never be null. An empty field has a zero-length string as the default value. To test if the field is empty use...

if (this.getField("myField").value.length == 0) {
    // do something 
}
else {
    // it has a value
}

or 

if (this.getField("myField").value == "") {
    // do something 
}
else {
    // it has a value
}
1
votes

If you're getting that error, it's because this.getField("myField") itself is returning null. So any attempt to use a property on what it returns will fail.

It sounds like you need a null guard:

var field = this.getField("myField");
if (field !== null) }
    // use `field.value` here...
}