Grails based survey system, the android app

Some time back I wrote an article describing the roosearch system I developed using grails. This is the second part, the android client, please checkout the previous article otherwise this might not make much sense!

After completing the grails component, I had a RESTful API available to me, and I just needed to build an app that could consume those services.

Customer lookup and QR codes

The app needs to be simple and quick to use, one of the things I remember from a UX discussion at DroidCon UK is “Don’t annoy your users, they control your app ratings and your income!”. In order to lookup the surveys quickly, I’ve added the ability to scan QR codes. Actually I didn’t have to do a great deal as there is already an app called ZXing by Google that scans QR codes, so I just needed to make Roosearch delegate to ZXing and handle the result.

Of course, we don’t want to exclude users that don’t have ZXing, or even a camera on their device, so I’ve also provided a text field where they can enter the customer Id manually if required.

When the user clicks on the “scan barcode” button, I first check if ZXing is installed using the following

    public void scanBarCode(View v) {
        final boolean scanAvailable = isIntentAvailable(this,
        if (!scanAvailable){
            Toast.makeText(this, "You need to install the ZXing barcode app to use this feature", Toast.LENGTH_SHORT).show();

        Intent intent = new Intent("");
        intent.putExtra("SCAN_MODE", "QR_CODE_MODE");
        startActivityForResult(intent, 0);

If the user does have ZXing installed on their device, and choose to use it, we can get the result back from the bar code scan using:

public void onActivityResult(int requestCode, int resultCode, Intent intent) {
        if (requestCode == 0) {
            if (resultCode == RESULT_OK) {
                String contents = intent.getStringExtra("SCAN_RESULT");
            } else if (resultCode == RESULT_CANCELED) {
                // Handle cancel

    private void performRooLookup(String rooId) {
        if (StringUtils.isBlank(rooId)) {
            Toast.makeText(this, "Please enter a valid customer id", Toast.LENGTH_SHORT).show();

        Integer customerId;
        try {
            customerId = Integer.parseInt(rooId);
        } catch (NumberFormatException e) {
            Toast.makeText(this, "Customer id needs to be numeric", Toast.LENGTH_SHORT).show();
        new FindRooTask(this, new FindRooTaskCompleteListener()).execute(customerId);

I then have the following buried in a service call, invoked by an AsyncTask, which handles finding Customer details:

    public Customer getCustomerDetails(int customerId) {

        try {
            final String url = "{query}";

            HttpHeaders requestHeaders = new HttpHeaders();

            // Create a new RestTemplate instance
            RestTemplate restTemplate = new RestTemplate();
            restTemplate.getMessageConverters().add(new MappingJacksonHttpMessageConverter());

            // Perform the HTTP GET request
            ResponseEntity<Customer> response =, HttpMethod.GET,
                    new HttpEntity<Object>(requestHeaders), Customer.class, customerId);

            return response.getBody();
        } catch (Exception e) {
            System.out.println("Oops, got an error retrieving from server.. + e");
         return null;

A Customer looks like this:

public class Customer implements Parcelable {

    private String companyName;
    private String twitter;
    private String facebook;
    private List<SurveySummary> surveys = new ArrayList<SurveySummary>();
    //Accessors omitted

The SurveySummary just has a title and Id. The reason for just returning summaries is because a customer may have many surveys, and there is no need to obtain them all, we just obtain the title to display to the user, if selected, we’ll retrieve the survey by its id.

To recap, here are 2 screenshots that show the above; the landing screen, and then the customer display screen

Landing screen for Roosearch, where the user can enter a customer Id or scan a QR code

Landing screen for Roosearch, where the user can enter a customer Id or scan a QR code

Customer screen, display social media links, name, photo, and list of surveys that the customer has

Customer screen, display social media links, name, photo, and list of surveys that the customer has


The survey engine

This is where the magic happens. I have a single activity and single view that handles presenting the survey to the user. As the surveys can change number of questions, and number of responses, I needed a way of dynamically traversing the survey object and allowing user to move between the questions whilst retaining state of what they have selected so far.

I’ve created the following method that will redraw the layout for a given question id:

    public void drawQuestionOnScreen(int id) {
        TextView question = (TextView) findViewById(;
        question.setText(s.getQuestion(id - 1).getText());   // subtract 1 as lists are indexed from 0

        LinearLayout linLay = (LinearLayout) findViewById(;
        RadioGroup rg = new RadioGroup(this);
        for (int aIndex = 0; aIndex < s.getQuestion(id - 1).getResponses().size(); aIndex++) {
            Answer a = s.getQuestion(id - 1).getAvailableOption(aIndex);
            RadioButton button = new RadioButton(this);

        TextView status = (TextView) findViewById(;
        status.setText(format("%d of %d", id, s.getQuestionCount()));

As you can see, it will retrieve the question by Id, then iterate over the responses and generate RadioButtons. Moving to the next question is reasonably easy, firstly I work out if an option has been selected, and prevent moving on if not. After that, I mark the selected response in the survey object, and then work out if there is another question in the sequence to display, if not we can progress to the finish.

One of the questions in the given survey

One of the questions in the given survey

    public void next(View v) {
        RadioGroup rg = (RadioGroup) findViewById(1);

        int selectedRadioId = rg.getCheckedRadioButtonId();
        if(selectedRadioId == -1){
            Toast.makeText(this, "Please select a response", Toast.LENGTH_SHORT).show();

        s.getQuestion(questionIndex - 1).getResponses().get(selectedRadioId).setSelected(true);
        // work out if there is another question, then move to it
        if (s.getQuestionCount() > 1 && questionIndex < s.getQuestionCount()) {
        } else {
            // if there are no other questions, show dialog saying submit or not
            Toast.makeText(this, "Reached the end of the survey", Toast.LENGTH_SHORT).show();
            // HERE we should process the entire survey, crunch data and post off (maybe async)

            Intent i = new Intent(this, SurveyComplete.class);
            i.putExtra("com.roosearch.domain.Survey", s);

A similar approach is needed for moving back to previous questions, determine if there is a previous question to move to then redraw the screen, like so:

    public void previous(View v) {
        // work out if there is a previous question, and if so move to it
        if (s.getQuestionCount() > 1 && questionIndex > 1) {
        } else {
            //if there are no other questions, move back to home screen, finish() this and scrap any progress

Once the user completes all questions, the SurveyComplete activity is invoked.

Completing a survey

When the user has completed all questions, the survey object is passed into the SurveyComplete activity, which handles sending the responses back to the grails web application.

    protected void onResume()
        TextView tv = (TextView) findViewById(;
        tv.setText("Thank you for taking the time to complete the survey");

        Survey s = getIntent().getExtras().getParcelable("com.roosearch.domain.Survey");

        if (s != null)
            StringBuffer sb = new StringBuffer();
            sb.append("\n" + s.getTitle() + "\n");
            for (Question q : s.getQuestions())
                sb.append("\nQ: " + q.getText());
                sb.append("\nA: " + q.getSelectedAnswer() + "\n");
            tv.append("\n\n" + sb.toString());

        new SurveyUploadTask(this, new SurveyUploadTaskCompleteListener()).execute(s);

    public class SurveyUploadTaskCompleteListener implements AsyncTaskCompleteListener<Void> {
        public void onTaskComplete(Void voidz) {
            Toast.makeText(SurveyComplete.this, "Survey uploaded", Toast.LENGTH_SHORT).show();

The activity uses an AsyncTask to post the data back to the grails API controller, and displays a toast when successful.

Survey completed, results uploaded, and summary presented to user

Survey completed, results uploaded, and summary presented to user


Wrapping it up

Overall quite a simple app, I spent probably around 2 or 3 weekends putting together, most of that time was spent getting to grips with some automated testing for android. The code is admittedly a little rough around the edges, but I was aiming for an MVP (most viable product) to get working, feel free to contribute or suggest improvements!

I chose to use maven, but would use gradle if I were to pick this up again. Be sure to check out the code on github and try running it against Roosearch web, it does work!

Click here for the source code on Github

Getting to grips with Grails, building a survey management system

Sometime in late 2012 I was discussing dissertation project ideas with my girlfriend, as she was coming up to her final year of a computing bachelors. The usual option chosen by many graduates would be to just build a website or an app, or do some form of market research. We decided to encompass all 3 to produce something that works, but ultimately something that could be of value. If I had the time, energy, and funds I’d pursue this as it has potential for a startup, but I don’t, so the important thing that I’ve taken away is the experience working with groovy, grails, and android.

The Idea…

There are 2 main business drivers behind this project. Firstly we wanted to provide a service whereby restaurant owners can register, create surveys, and make them accessible to staff such as printing QR codes onto the back of their menus. Secondly, we wanted to approach this from the end users point of view, whereby customers sitting in the restaurant could download an app for free off the public market places, scan the said QR code, and be presented with the survey the restaurant owner had created. They would fill it in via the app and submit, the restaurant owner then has immediate access to the results in the form of statistics and graphs.

Landing page for Roosearch

Landing page for Roosearch

The outcomes that we’re after:

  • Better visibility to restaurant owners on how their customers feel
  • Easy and seamless access to surveys for the customers
  • A scalable application which can handle increasing users as demand grows
  • A platform for advertising new products and features

There are 3 components to this solution:

  1. Grails web application
  2. Rest API (built into the grails application)
  3. Android app

Why Grails?

  • Develop in groovy, so very accessible to java developers.
  • Quick to prototype with “convention over configuration”
  • Views auto generated if using scaffolding.
  • Easily deployable into the cloud, package as a war and deploy to cloudbees

The Prototype…

If you’re starting out with grails, I’d highly recommend that you get a copy of IntelliJ ultimate edition (and a copy of Grails in action), the support for grails is fantastic and I found it far easier than using eclipse. Whilst there are some excellent tutorials on grails out there (the official documentation is also very good) I’ll hold off and just jump right into how the application works.

One of the awesome features of grails is that it follows the “convention over configuration”, which simply means that if you follow the convention implied by the framework, you don’t have to be concerned about configuration. You can’t escape configuration entirely, but boilerplate plumbing can be inferred by convention. An example of that is if you name your controllers like “SurveyController”, grails automatically knows its a controller for the survey class, based on naming conventions. A similar convention applies for views.

Domain model

Roosearch entity relationship diagram

Roosearch entity relationship diagram

Our data model is quite simple. We have a user, the user has some surveys, each survey has a number of questions, and each questions has a number of predefined responses. The domain classes are self explanatory, but it’s probably worth mentioning a few tweaks I made.

class User {
    String firstName
    String lastName
    String emailAddress
    String companyName
    String facebookPageLink
    String twitterHandle

    static hasMany = [surveys: Survey]
    static constraints = {
        facebookPageLink nullable: true
        twitterHandle nullable: true

By default, all fields are mandatory, however in the above example of the User class we can override these constraints to set them as nullable. There are various other constraints that you can set, have a look at the documentation.

class Survey {

    Integer id
    String title

    static hasMany = [questions: Question]

    static mapping = {
        questions lazy: false

    static constraints = {

    String toString(){
        return title

The relationships between the classes are defined by the “static hasMany”. This basically says that one Survey has relationships to many Questions, and this relationship is identified by “questions”.

The mapping block instructs the questions to be eagerly loaded, so once a survey is loaded into memory, so are all of its questions, opposed to just the Ids which would then be loaded lazily.

It’s also useful to override the toString method on your domain objects, particularly if you have relationships as the scaffolding will create drop down lists in your views. If you don’t override toString with something sensible, you’ll just see the object hash codes instead, which isn’t very useful to the user.


It’s the responsibility of the controllers to manipulate the underlying data model (via services for example), and respond with views to the user. You can read more about the MVC pattern here.

To get started, you could simply enable scaffolding like so.

class LoginController {

    static scaffold = true

    def index = {
        render(view: "login.gsp")

Scaffolding is an excellent feature of grails to get you started. Grails knows the structure of your domain object, therefore it is able to dynamically create controller CRUD operations, and views to manipulate your objects. That one small line of code and you can create, updated, delete, and view your objects! Fantastic eh?!

The bad news…

Whilst scaffolding is great to get you started, the moment you want to do something out of the ordinary, or customisation on views, scaffolding becomes a bit useless, and you’ll have to implement your own controllers (and possibly views). Fortunately, grails is quite flexible so you can leave scaffolding on and just override the methods that you want to customise. As with views, you’re best off getting grails to generate them for you and then customise them, to save you having to write the entire controller/view from scratch.

The methods you can override, and there general uses are:

  • index – default action, usually just redirects to list
  • list – list all of the objects, handle pagination, filtering etc
  • create – render view to create new object
  • save – handle creation of new object, validation etc.
  • edit – render view to edit an object
  • update – handle update of object
  • delete – delete an object

You can read more about the controller actions on the grails documentation.

You can see in the show() method on the SurveyController that I’ve customised it to to add some charts into the response model. You can see how I generate the chart data by looking at the source code in github. The view can then render these as javascript charts (which I’ll come onto in a moment)

    def show(Long id) {
        def surveyInstance = Survey.get(id)
        if (!surveyInstance) {
            flash.message = message(code: 'default.not.found.message', args: [message(code: 'survey.label', default: 'Survey'), id])
            redirect(action: "list")

        def charts = getCharts(surveyInstance)

        [surveyInstance: surveyInstance, charts: charts]


Being quite fond of the default views that grails generates, and not wanting to invest a great deal of time with customisation for this prototype, I chose to generate the views and then just tweak as I needed. In reality, the only customisation I needed to do was to place a “generate QR code” link, and to insert some javacript charts for displaying survey statistics.

Having assessed HighCharts, D3, and the Google visualisation API, I opted for the latter as I felt it was far simpler to use and I didn’t have any need for the advanced features that HighCharts and D3 come with, and there was a plugin for gvisualisation.

Displaying charts was straightforward, after installing the visualisation plugin, add this snippet of code to iterate over the charts that were added to the model and display a barCoreChart.

<g:each in="${charts.values()}" var="item">
                    width="${400}" height="${240}"

            <div id="chart-${item.question_id}" align="center"></div>

This would then display something like the following, you can change various elements of the charts such as the chart type, axis labels, sizes and titles, please refer to the documentation.

Charts using Google Visualisation

Charts using Google Visualisation

QR codes

QR codes make it incredibly easy to share data to android devices, my intention was to embed a user ID in a QR code, when scanned the app can request all surveys pertinent to the user ID.

Generating QR codes is easy with the qrcode plugin. I have provided a link on the users view to generate a QR code:

<span class="property-value" aria-labelledby="qr-label">
                <g:link controller="user" action="generateQrCode" id="${}">Generate QR Code</g:link>

This is bound to the generateQrCode action on the user controller, which will create a QR code from a user id and display it

    def generateQrCode(Long id){
        println "Generate QR code here..."
        String data = "$id"
        int qrSize = 500

        QRCodeRenderer qrcodeRenderer = new QRCodeRenderer()
        qrcodeRenderer.renderPng(data, qrSize, response.outputStream)

As you can see, it is as simple as providing the data to be encoded, the size (x==y), and the output stream, in this case the response. When you click the link, you should see the following:

QR code generated by the qrcode plugin

QR code generated by the qrcode plugin


The website element is designed for the restaurant owners, the end users will be using an android app to complete surveys. Whilst I could have developed a mobile responsive page, I felt that an android app would bring a better overall experience to the user.

I have created a controller, ApiController that enables users to request surveys, and post responses.

Firstly, I created the URL mappings for this new controller

	static mappings = {
        "/api/customer/$customerid"(controller: "api", action: 'getCustomer')
        "/api/survey/$surveyid"(controller: "api", action: [GET: 'getSurvey'])
        "/api/survey"(controller: "api", action: [POST: 'surveyComplete'])

            constraints {
                // apply constraints here

		"/"(controller: "home")

Requests on /api/customer/$customerid, such as /api/customer/123 are routed to the getCustomer method on the api controller. The same is true for the second mapping, however the action is a GET on getSurvey (in hindsight, the first mapping should be restricted to the GET method too). The third mapping is a POST on /api/survey which will be invoked when the user has completed a survey on their device.

    def getCustomer(){
        User u = User.get(params.customerid)

        def surveysToPresent = [:]

        u.surveys.each {
            surveysToPresent << [title: it.title, id:]
        render(contentType: 'text/json') {[
                'company_name': u.companyName,
                'twitter' : u.twitterHandle,
                'facebook' : u.facebookPageLink,
                'surveys' : [surveysToPresent]
        ]} as JSON

The getCustomer method finds the user from the customerid on the request path, retrieves the surveys and transforms them to a map containing the title and id (we don’t need the entire survey object when the user is presented with a list of surveys to select). The render statement enables us to return a json response very easily, we just return a map and grails (jackson) takes care of the json marshalling.

    def getSurvey(){
        Survey s = Survey.get(params.surveyid)

        def questionsToPresent = [:]

        questionsToPresent = s.questions.collect {
                    text: it.text,
                    responses : it.responses.collect{ resp ->
                        [id:, text: resp.text]

        render(contentType: 'text/json') {[
                'id' :,
                'title': s.title,
                'questions' : questionsToPresent
        ]} as JSON

The getSurvey method behaves in a similar manner to getCustomer, it builds a map and renders as json.

    def surveyComplete(){
        def jsonObject = request.JSON

        Survey theSurvey = Survey.findById(

        jsonObject.responses.each{ response ->
            theSurvey.questions.find { == response.question_id}.responses.find { == response.response_id}.numberOfPeopleSelected++
        } true, failOnError: true)

        render(status: 204)

The surveyComplete will retrieve a survey by id, find the responses the user has provided, and increment a count. The survey is then saved and a “204 No Content” is returned.

I’ll cover how the android app consumes these services in my next post.


As this project is just a prototype, I decided to host it on a free Cloudbees instance. The application doesn’t have any persistence layer, and all data is held in memory (which is fine for its current purpose), so when Cloudbees hibernates the instance after a period of inactivity, all user data will be lost. Deploying is simple, build the war using

grails war

Then upload the war file from the target directory to your cloud bees account, or use the command line cloud bees SDK.

View source code on Github

View live demo

(if the live demo link doesn’t work, try again in 10 minutes as the instance will be waking from hibernation)


Bootstrapping a Grails application to prepopulate data on startup

I’ve been dabbling in a little Grails recently, and I found it quite frustrating having to re-enter some sample data everytime I restarted my application, in order to have the views look meaningful.

Fortunately, theres an easy solution, just do all of your setup in the Bootstrapper class like so :

class BootStrap {

def init = { servletContext -&gt;

// Keep references on these as we'll use them for populating sample surveys
Response great = new Response(text: "Great").save()
Response average = new Response(text: "Average").save()
Response poor = new Response(text: "Poor").save()
Response tasty = new Response(text: "Tasty").save()
Response ok = new Response(text: "OK").save()
Response horrible = new Response(text: "Horrible").save()
Response friends = new Response(text: "Friends").save()
Response advert = new Response(text: "Advert").save()
Response radio = new Response(text: "Radio").save()

// These are some other responses that we'll make available in the response bank
["Excellent", "Good", "Satisfactory", "Bad", "Very bad", "true", "false", "Yes", "No", "Maybe"].each {
new Response(text: it).save()

Question q1 = new Question(text: "What did you think of the service?", responses: [great, average, poor]).save()
Question q2 = new Question(text: "Was the food nice?", responses: [tasty, ok, horrible]).save()
Question q3 = new Question(text: "How did you hear about our establishment?", responses: [friends, advert, radio]).save()

Survey cosmos = new Survey(title: "COSMOs customer feedback", questions: [q1, q2, q3]).save()
Survey jimmys = new Survey(title: "Jimmys Kitchen customer feedback", questions: [q1, q2, q3]).save()

new User(firstName: 'James',
lastName: 'Elsey',
emailAddress: '',
companyName: 'Jimmys Kitchen',
surveys: [jimmys])

new User(firstName: 'Manabu',
lastName: 'Takano',
emailAddress: '',
companyName: 'COSMOs Cardiff',
surveys: [cosmos])

def destroy = {

Then, every time you start the application, you can be sure that it has the above data populated.

Probably not ideal for production apps, but very useful in development

Override the toString on your domain classes so they display as something useful

If you’re finding that your domain objects are not being displayed in a readable manner, chances are its because they haven’t been told to. This is often the case in drop down menus that the grails scaffolding creates. You can easily fix this by overriding the toString method on your domain class, such as the following.

class Question {

    String text

    static hasMany = [responses: Response]

    static constraints = {

    String toString(){
        return text