Write the styleExportTagMap to a text file

[IowaBoy9]

I am attempting to write the paragraph style name and its class as defined in the styleExportTagMap of all paragraphs in a document. Here is my javascript so far:
var path = '~/00_temp/';
var filename = 'styleMap.txt';

//Create File object
var file = new File(path + filename);
file.encoding = 'UTF-8';
file.open('w');

//gather data and write it to file
var ps = app.documents[0].allParagraphStyles
while(a = ps.pop())
file.write(a.name+'\t'+a.styleExportTagMaps.toSource()+'\n');

file.close();

Here is the line for the paragraph style TEXT_First_ParaDropCap

TEXT_First_ParaDropCap resolve("/document[@id=4]//paragraph-style[@id=291]/style-export-tag-map")

What I desire is Something like this:

TEXT_First_ParaDropCap class: body_dropCap 

I will be up front. I am not sure how to manage toSource(). 

[brianp311]

Assuming each style has only one tag map: 

file.write(a.name+'\t'+a.styleExportTagMaps[0].class+'\n');

[IowaBoy9]

Thanks brianp311

I get a error: Object does not support the property or method 'class'. 

[IowaBoy9]

I tried replacing .class with .exportClass and receive the same error.

file.write(a.name+'\t'+a.styleExportTagMaps[0].exportClass+'\n');

[brianp311 · Accepted solution]

My bad, yes exportClass. You probably got an Object is Invalid error, which you would see if no export tag/class was applied. 

Wrap it in a try/catch: 

try { file.write(a.name+'\t'+a.styleExportTagMaps[0].exportClass+'\n'); }
catch(e) { file.write(a.name + "\tNo export tag applied!"; } 

[IowaBoy9]

Thanks. That worked. You missed the closing parenthesis in the catch(e). Otherwise. Perfect! Thanks again.

{ file.write(a.name + "\tNo export tag applied!"); }