Google Apps Script for Beginners: Building on your basic JavaScript knowledge, this book takes you into the world of Google Apps Script and shows you how to develop and customize your own apps. The step-by-step approach provides all the necessary skills.

The forms service has quite a lot of methods presented in the Google documentation, but some of the aspects of form creation and modification are still a bit complex to apprehend (https://developers.google.com/apps-script/reference/forms/).

To create a form, we only need a script in a project. This project can either be bound to a document or can be a standalone file in your drive.

Since the script actually creates a new form and a new spreadsheet to get responses from, we have no special interest in using a spreadsheet-bounded script or a form-bounded one. The following code creates a simple form; its contents are directly inspired by the example that Google provides in its documentation. We will see what we can do with it using only script. It will be an opportunity to see how we can change the form content and presentation (read the comments if you're not sure how it works).

// Global variable = constants
var ssId = ScriptProperties.getProperty('ssId');
if(ssId ==...

There are a few things we cannot achieve with FormApp. For example, there is no way to catch user response and modify a form according to their answers. The only form-related event that we can catch is the form submission itself; that is, we can catch the occurrence of an event when the form is submitted and all the data is already recorded. It's a major limitation of this service, but we'll see that it's possible to do so using other approaches.

The function we wrote in the script earlier will not be very useful if we have to run it manually (we won't be there to monitor every time someone fills a form). So, we should capture the event when someone sends a form so that we are informed by an e-mail message.

We already see the events available in the spreadsheet, so we know how it works. Just go to the Resources menu in the script editor to set up a new trigger On form submit as shown in the following screenshot:

Now the script will send us a message every time a form is filled. Note that the sidebar UI won't be updated since it can only work in cases where a user actually uses the form editor UI.

If you need to customize your forms further than what Google's forms service offers or if you don't like to see Google's messages and logo on all the forms you send (these are indeed quite obvious), Google Apps Script has two UI-oriented services you can use. Both are capable of developing very complex UIs, the second being even more powerful as it includes the possibility to use external JavaScript libraries, such as jQuery.

We saw in the previous form example that we can create small user interfaces to enhance the standard form UI. This is also available in documents and spreadsheets, although it is slightly different. I decided to use both of them in this small example to encourage you to experiment and customize more because, even if it takes some time to develop these tools, it is so rewarding from a personal point of view that it's well worth the pain.

UiApp was the first service available in Google Apps Script a few years ago and is still presented as experimental in the documentation, although no announcement has been made (for now) that they will deprecate it in the near future. Google encourages users to switch to an HTML service as this one will continue to be upgraded.

In the meantime, we will continue to show both of them as they both have strengths and weaknesses.

A forms service can actually be very useful to teachers or other people who need to create lots of forms or questionnaires, often using the same structure.

The ability forms have to respond to triggers provides the possibility to automatically send back an evaluation with reference to good and bad answers.

The academic community is probably the group most interested in this Google app.

It gives us the opportunity to use function parameters to split our code into smaller and simpler parts.

Our last example introduced the key word of the next chapter: e-mail.