> Samples & Tips > Sample Apps > Hello World App

Hello World App

This sample app is a Core Cordova Plugins Demo showing several device functionalities such as camera, contacts, compass and so on.

Demo

Import Hello World App to your Monaca Account

Tested Environment

Android 9.0
iOS 12.1.1

File Components

File	Description
`index.html`	The Startup page
`phonegap-demo.html`	The Core Cordova Plugins Demo page
`phonegap-demo/master.css`	The style sheet for the Core Cordova Plugins Demo page
`phonegap-demo/main.js`	The JavaScript file handling implementation in the Core Cordova Plugins Demo page
`css/style.css`	The style Sheet for the whole application
`img/icon/*.png`	All icon files needed to use this template

Required JS/CSS Components

jQuery

HTML Explanation

index.html

index.html is the Startup page.

<body>
    <h1>HelloWorld!</h1>
    <a class="button--large" href="phonegap-demo.html">Start Demo</a>
</body>

The above html code inside the <body> tag is showing a HelloWorld! phrase and a Start Demo button as shown below.

phonegap-demo.html

phonegap-demo.html shows a Core Cordova Plugins Demo with the basic phone information and a list of functions as below:

Toggle Accelerometer: Start or stop the measurement of the phone’s movement.
Get Location: Get current location of the phone.
Call 411: Call 411.
Vibrate: Vibrate the phone.
Get a Picture: Turn on the phone’s camera.
Get Phone’s Contacts: Get the total number of contacts in the phone and display the third contact name.
Check Network: Check the current type of network the phone is using.
Toggle Compass: Start or stop the phone compass.

The JavaScript code corresponds to these functions will be explained in the next section.

JavaScript Explanation

The main.js is a JavaScript file handling the implementation of the Core Cordova Plugins Demo page. There are 8 main functions in this file:

Toggle Accelerometer

Start or stop the measurement of the phone’s movement. Below is the JavaScript code of this function:

...
var accelerationWatch = null;

function updateAcceleration(a) {
  document.getElementById('x').innerHTML = roundNumber(a.x);
  document.getElementById('y').innerHTML = roundNumber(a.y);
  document.getElementById('z').innerHTML = roundNumber(a.z);
}

var toggleAccel = function() {
  if (accelerationWatch !== null) {
    navigator.accelerometer.clearWatch(accelerationWatch);
    updateAcceleration({
        x : "",
        y : "",
        z : ""
    });
    accelerationWatch = null;
  } else {
    var options = {};
    options.frequency = 1000;
    accelerationWatch = navigator.accelerometer.watchAcceleration(
        updateAcceleration, function(ex) {
            alert("accel fail (" + ex.name + ": " + ex.message + ")");
        }, options);
  }
};
...

When click on the Toggle Accelerometer button, you can either start or stop the measurement of the phone’s movement. If it is started, the X, Y & Z values change; otherwise, they will appear as 0.

Get Location

Get current location of the phone. Below is the JavaScript code of this function:

...
var getLocation = function() {
  var suc = function(p) {
      alert(p.coords.latitude + " " + p.coords.longitude);
  };
  var locFail = function() {
  };
  navigator.geolocation.getCurrentPosition(suc, locFail);
};
...

When click on the Get Location button, a message showing the current location of phone will appear as below:

Call 411

Call 411. Below is the JavaScript code of this function:

...
<a href="tel:411" class="btn large">Call 411</a>
...

In order to use the href="tel:411", the following setting is needed in config.xml file:

<allow-intent href="tel:*" />

When click on the Call 411 button, a confirmed message of the call is appeared.

Vibrate

Vibrate the phone. Below is the JavaScript code of this function:

...
var vibrate = function() {
  navigator.notification.vibrate(0);
};
...

When click on the Vibrate button, you will notice that your phone vibrates.

Get a Picture

Turn on the phone’s camera. Below is the JavaScript code of this function:

...
function dump_pic(data) {
  var viewport = document.getElementById('viewport');
  console.log(data);
  viewport.style.display = "";
  viewport.style.position = "absolute";
  viewport.style.top = "10px";
  viewport.style.left = "10px";
  document.getElementById("test_img").src = data;
}

function fail(msg) {
  alert(msg);
}

function show_pic() {
  navigator.camera.getPicture(dump_pic, fail, {
    quality : 50
  });
}
...

When click on the Get a Picture button, the phone camera is turned on. If you take a picture and use it, it will be displayed in the page as shown below otherwise a message will be displayed (see below):

Get Phone’s Contacts

Get the total number of contacts in the phone and display the third contact name. Below is the JavaScript code of this function:

...
function contacts_success(contacts) {
  alert(contacts.length
          + ' contacts returned.'
          + (contacts[2] && contacts[2].name ? (' Third contact is ' + contacts[2].name.formatted)
                  : ''));
}

function contacts_failed(msgObject){
  alert("Failed to access contact list:" + JSON.stringify(msgObject));
}

function get_contacts() {
  var obj = new ContactFindOptions();
  obj.filter = "";
  obj.multiple = true;
  navigator.contacts.find(
          [ "displayName", "name" ], contacts_success,
          contacts_failed, obj);
}
...

When click on the Get Phone's Contacts button, the total number of contacts in the phone and the third contact name will be displayed as follows:

Check Network

Check the current type of network the phone is using. Below is the JavaScript code of this function:

...
function check_network() {
  var networkState = navigator.network.connection.type;

  var states = {};
  states[Connection.UNKNOWN]  = 'Unknown connection';
  states[Connection.ETHERNET] = 'Ethernet connection';
  states[Connection.WIFI]     = 'WiFi connection';
  states[Connection.CELL_2G]  = 'Cell 2G connection';
  states[Connection.CELL_3G]  = 'Cell 3G connection';
  states[Connection.CELL_4G]  = 'Cell 4G connection';
  states[Connection.NONE]     = 'No network connection';

  confirm('Connection type:\n ' + states[networkState]);
}
...

When click on the Check Network button, the current network type information will be displayed.

Toggle Compass

Start or stop the phone compass. Below is the JavaScript code of this function:

...
var watchID = null;

function updateHeading(h) {
  document.getElementById('h').innerHTML = h.magneticHeading;
}

function toggleCompass() {
  if (watchID !== null) {
    navigator.compass.clearWatch(watchID);
    watchID = null;
    updateHeading({ magneticHeading : "Off"});
  } else {
    var options = { frequency: 1000 };
    watchID = navigator.compass.watchHeading(updateHeading, function(e) {
      alert('Compass Error: ' + e.code);
    }, options);
  }
}
...

When click on the Toggle Compass button, you can either start or stop the phone compass. If the compass is started, the value of the compass heading changes; otherwise, it will appear as off. For example: