0
Hello, studying a little about Cordova and Phonegap, specifically the default application, Helloworld, I noticed the line: Document.addeventlistener('deviceready', this.onDeviceReady, false); which is in a js file (index.js). So, as far as I know, addeventlistener, from what I saw in W3school, it has the event as the first parameter, the function as the second, and an optional boolean as the third. But in the example I put, the 'deviceready' which is the element, is in the place of the event? Is that? and this "this" in the parameter: "thisonDeviceReady". Because I have used addeventlistener several times like this: [Document.getElementById('elementox'). addeventlistener('click',myfunction); that’s why I didn’t understand. I ask for help on this. I think the answer/explanation, may be in the code (commented) Phonegap, but, besides being in English, I saw and reviewed, but I could not understand.
Here are the codes:
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
var app = {
// Application Constructor
initialize: function() {
this.bindEvents();
},
// Bind Event Listeners
//
// Bind any events that are required on startup. Common events are:
// 'load', 'deviceready', 'offline', and 'online'.
bindEvents: function() {
document.addEventListener('deviceready', this.onDeviceReady, false);
},
// deviceready Event Handler
//
// The scope of 'this' is the event. In order to call the 'receivedEvent'
// function, we must explicitly call 'app.receivedEvent(...);'
onDeviceReady: function() {
app.receivedEvent('deviceready');
},
// Update DOM on a Received Event
receivedEvent: function(id) {
var parentElement = document.getElementById(id);
var listeningElement = parentElement.querySelector('.listening');
var receivedElement = parentElement.querySelector('.received');
listeningElement.setAttribute('style', 'display:none;');
receivedElement.setAttribute('style', 'display:block;');
console.log('Received Event: ' + id);
}
};<!DOCTYPE html>
<!--
Copyright (c) 2012-2016 Adobe Systems Incorporated. All rights reserved.
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License.
-->
<html>
<head>
<meta charset="utf-8" />
<meta name="format-detection" content="telephone=no" />
<meta name="msapplication-tap-highlight" content="no" />
<meta name="viewport" content="user-scalable=no, initial-scale=1, maximum-scale=1, minimum-scale=1, width=device-width" />
<!-- This is a wide open CSP declaration. To lock this down for production, see below. -->
<meta http-equiv="Content-Security-Policy" content="default-src * 'unsafe-inline'; style-src 'self' 'unsafe-inline'; media-src *" />
<!-- Good default declaration:
* gap: is required only on iOS (when using UIWebView) and is needed for JS->native communication
* https://ssl.gstatic.com is required only on Android and is needed for TalkBack to function properly
* Disables use of eval() and inline scripts in order to mitigate risk of XSS vulnerabilities. To change this:
* Enable inline JS: add 'unsafe-inline' to default-src
* Enable eval(): add 'unsafe-eval' to default-src
* Create your own at http://cspisawesome.com
-->
<!-- <meta http-equiv="Content-Security-Policy" content="default-src 'self' data: gap: 'unsafe-inline' https://ssl.gstatic.com; style-src 'self' 'unsafe-inline'; media-src *" /> -->
<link rel="stylesheet" type="text/css" href="css/index.css" />
<title>Hello World</title>
</head>
<body>
<div class="app">
<h1>PhoneGap</h1>
<div id="deviceready" class="blink">
<p class="event listening">Connecting to Device</p>
<p class="event received">Device is Ready</p>
</div>
</div>
<script type="text/javascript" src="cordova.js"></script>
<script type="text/javascript" src="js/index.js"></script>
<script type="text/javascript">
app.initialize();
</script>
</body>
</html>
In the matter
devicereadyis the event andthis.onDeviceReadyis the function that is just below. How Javascript functions behave in relation to the scope?– NoobSaibot
Noobsaibot... so I searched, there is no onDeviceReady event in the Javascript event list! And how can the example use such an event?
– Fernandes