How to use the offline file system module for NativeScript, assuming each function is a tap event handler. It also assumes we know the structure of the data coming back out of the file.

nativescript-use-offline-module.js

var offlineModule = require("./modules/offline/offline");

exports.onTapClear = function() {
    console.log("clearing file");  

    offlineModule.remove().then(function() {
        console.log("finished clearing file");
    });
};

exports.onTapWrite = function() {
    console.log("writing to file");

    var items = [{"id": "1", "value": "bob"}, {"id": "2", "value": "tom"}];
    offlineModule.write(items)
        .then(function() {
            console.log("wrote " + items.length + " items to offline file");
        }, function(error) {
            // error! 
        }).then(function() {
            console.log("finished writing to file");
        });
};

exports.onTapRead = function() {
    console.log("reading from file");

    var items = [];
    offlineModule.read()
        .then(function(content) {
            console.log("read from file: " + content);
            var data = JSON.parse(content);
            data.forEach(function(item) {
                items.push(item); 
            });          
        }, function (error) {
            // error    
        }).then(function() { 
            console.log("finished reading " + items.length + " items from file");
        });
};