Libraries

Libraries are essentially JavaScript files where you can store code that is intended to be shared across various sections of your application. For instance, you might create a library to handle the encoding and decoding of strings, a functionality required in multiple actions throughout your application. Instead of duplicating these algorithms within each action, you can centralize them within a library and invoke them from your actions.

The structure of a library’s code is depicted as follows:

var privateFunction = function(msg) {
  return '['+msg+']';
};

exports.logSomething = function(msg) {
  sys.logs.info('*** logged from library: '+privateFunction(msg));
};

The crucial component here is the exports variable. Any elements you wish to make available from the library should be added to this object. Otherwise, they will remain inaccessible, as demonstrated by the privateFunction in the preceding example.

To access the library, you can use the namespace app.<libraryName> from any script. For instance, if the library in the provided example is named utils, you can employ the library in this manner within any script of the application:

var msg = record.field('description').val();
app.utils.logSomething(msg);

If an attempt is made to call app.utils.privateFunction(msg), an error will be thrown because that method was not exposed using the exports variable.

In the exports variable, you have the flexibility to include various entities; it need not be limited to functions alone. You could expose constants, as demonstrated below:

exports.MAX_ORDERS = 100;
exports.MAX_AMOUNT = 50000;