getField returns null in document level javascript

Forum|Forum|9 years ago
May 14, 2016
5 replies
6251 views

The code shows as below:

app.alert(1);

app.alert(this.getField("IsModified").value);

app.alert(2);

I put the script in document level. When I finish editing the script, it gives me 3 popup as expected.

After I closed the PDF and reopen it, it gives me the first popup ONLY.

I checked the debugger. It gave me the error as below:

TypeError: this.getField(...) is null

3:Document-Level:alertTest

I can tell the problem is on this.getField("IsModified"). But why this happens? And how should I fix it?

This topic has been closed for replies.

J

jrbranaa

Participant

Hello,

I am running into what appears to be the same problem. I have this document level script that returns "null" when I perform a getField when I first open the document. If however I interact with another part of the document OR I put it in "Prepare Form" mode in Acrobat DC and then back into preview, it works just fine. So I know the field name is correctly spelled.

It almost appears as if the field object doesn't get created upon document launch, but that something triggers the field creation later.

Any thoughts? Did you resolve this issue?

Cheers

G

gkaiseril

Inspiring

To have a field object you need an open PDF form. Do you have an open form at the yime the script is running?

G

gkaiseril

Inspiring

Try the following script:

app.alert(1);
var oField = this.getField("IsModified"); // get field object;
// see if there was an error accessing the field object;
if(oField == null) {
app.alert({cMsg: "Error accessing field \"IsModified\".\nPlease check field name, spelling, and capitialization.",
nIcon: 1,
nType: 0,
cTitle: "Field Error Condition"
});
} else {
app.alert(this.getField("IsModified").value);
}
app.alert(2);

This script check the return value for the getField method and issues an alert if there was a problem accessing the provided field name. Check to make sure the field really exist.

I add a document level function that I use in place of the this.getField method which includes the check of the return value for the this.getFeild method.