I am developing a Cordova App for iOS with an IndexedDB Database in the background. Here is my code for opening the database:
indexedDB = window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB || window.msIndexedDB || window.shimIndexedDB;
window.IDBTransaction = window.IDBTransaction || window.webkitIDBTransaction || window.msIDBTransaction;
window.IDBKeyRange = window.IDBKeyRange || window.webkitIDBKeyRange || window.msIDBKeyRange;
if (!indexedDB) {
window.alert("Your browser doesn't support a stable version of IndexedDB.");
}
console.log("openDb ...");
var req = indexedDB.open(insectDbName, 21);
console.log(req);
req.onsuccess = function(evt) {
debugger;
db = this.result;
console.log("openDb DONE");
};
req.onerror = function(evt) {
//debugger;
console.error("openDb: ", evt.target.errorCode);
};
req.onupgradeneeded = function(evt) {
console.log("openDb.onupgradeneeded");
//debugger;
var versionStore = evt.currentTarget.result.createObjectStore(versionStoreName, { autoIncrement : true});
console.log("versionStore created");
};
Now, my problem is, when I open the database, the request is no IDBOpenRequest object. But the events are firing. When I open the database with a new version number, the onupgradeneeded event is called. And when I open with the current version, the onsuccess event is called.
The problem is, that the objectstores are never created, because in the onupgradeneeded event, evt.currentTarget is null.
I have already included the IndexedDBshim and the Cordova IndexedDB Plugin but it is still not working.
Has anybody encountered similar problems?
Ok, I found the problem. I had to use evt.target instead of evt.currentTarget.
Related
environment: use webview load remote url in ipad(iPad mini5, the version is 14.6), when the remote url loaded and execute then code is shown below, and nothing print. It seems that indexedDB.open() does not have any return.
After my testing, there will only be problems with version 14.6, and there will be no problem with versions below ios 14.4. I'm not sure if it's a webview problem or an indexedDB problem
var dbName = "test";
var dbVersion = 1;
var indexedDB = window.indexedDB ||
window.webkitIndexedDB ||
window.mozIndexedDB;
var db = '';
console.log("setup indexed db");
var request = indexedDB.open(dbName, dbVersion);
request.onsuccess = function(e) {
console.log("db request success");
};
request.onblocked = function(e) {
console.log("DB open blocked", e);
};
request.onerror = function(err) {
console.log("error", err);
};
request.onversionchange = function(err) {
console.log("onversionchange", err);
};
request.onupgradeneeded = function(e) {
console.log("upgrade needed");
};
After testing, it was found that there would be a problem with wkWebview and that using uiWebview would not. So I think there's a problem with the new version of ios wkWebview for indexedDB compatibility
when I update my iPad from 7.1 to 8.1，my application with cordova can't run.
Here is the code:
if (typeof window.indexedDB == "undefined") {
alert("Your system does not support indexdDB!")
} else {
var request, db;
alert("window.indexedDB:" + window.indexedDB); // null
request = window.indexedDB.open("ios8", 2); // error
}
But when I open it in browers(IE,chrome,safari), it works.
why the indexedDB is null?
I had resolved the problem now.
I use shimIndexedDB(https://github.com/axemclion/IndexedDBShim)!
After it was required,add this code:
if (!window.indexedDB) {
window.indexedDB = window.shimIndexedDB;
}
then everything is okey :)
I am developing an app using Web Audio Api. I have discovered that there is a memory leak in the way that Safari handles audio and doesn't garbage college the Audio Context correctly. For this reason I wish to load a new page. Have that page create the Audio Context, complete the operation and then close the window, so that the memory is released.
I have done the following to achieve this.
ref = window.open('record.html', '_self'); This will open the record.html page in the Cordova WebView according to https://wiki.apache.org/cordova/InAppBrowser
1 window.open('local-url.html');// loads in the
Cordova WebView
2 window.open('local-url.html', '_self');
// loads in the Cordova WebView
The record.html page loads a javascript file, that runs the operations that I wish to run. Here is the recordLoad.js file that makes some calls to native operations ( The native API is only available if loaded in the Cordova Webview and as you can see I need to access the file system, so this is the only way I can see to do it.
window.onload = createAudioContext;
ref = null;
function createAudioContext(){
console.log('createAudioContext');
window.AudioContext = window.AudioContext || window.webkitAudioContext;
navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia;
window.URL = window.URL || window.webkitURL;
audioContext = new AudioContext;
getDirectory();
}
function getDirectory(){
console.log('getDirectory');
window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, getFileSystem, fail);
}
function getFileSystem(directory){
console.log('getFileSystem');
var audioPath = localStorage.getItem('audioPath');
directory.root.getFile(audioPath, null, getVocalFile, fail);
}
function getVocalFile(fileEntry){
console.log('getVocalFile');
fileEntry.file(readVocalsToBuffer, fail);
}
function readVocalsToBuffer(file){
console.log('readVocalsToBuffer');
var reader = new FileReader();
reader.onloadend = function(evt){
var x = audioContext.decodeAudioData(evt.target._result, function(buffer){
if(!buffer){
console.log('error decoding file to Audio Buffer');
return;
}
window.voiceBuffer = buffer;
buffer = null;
loadBuffers();
});
}
reader.readAsArrayBuffer(file);
}
//web
function loadBuffers(){
console.log('loadBuffers');
var srcSong = localStorage.getItem('srcSong');
try{
var bufferLoader = new BufferLoader(
audioContext,
[
"."+srcSong
],
createOffLineContext
);
bufferLoader.load()
}
catch(e){
console.log(e.message);
}
}
//
function createOffLineContext(bufferList){
console.log('createOfflineContext');
offline = new webkitOfflineAudioContext(2, window.voiceBuffer.length, 44100);
var vocalSource = offline.createBufferSource();
vocalSource.buffer = window.voiceBuffer;
vocalSource.connect(offline.destination);
var backing = offline.createBufferSource();
backing.buffer = bufferList[0];
backing.connect(offline.destination);
vocalSource.start(0);
backing.start(0);
offline.oncomplete = function(ev){
bufferList = null;
console.log('audioContext');
console.log(audioContext);
audioContext = null;
console.log(audioContext);
vocalSource.stop(0);
backing.stop(0);
vocalSource.disconnect(0);
backing.disconnect(0);
vocalSource = null;
backing = null;
window.voiceBuffer = null;
window.renderedFile = ev.renderedBuffer;
var bufferR = ev.renderedBuffer.getChannelData(0);
var bufferL = ev.renderedBuffer.getChannelData(1);
var interleaved = interleave(bufferL, bufferR);
var dataview = encodeWAV(interleaved);
window.audioBlob = new Blob([dataview], {type: 'Wav'});
saveFile();
}
offline.startRendering();
}
// This file is very long, but once it is finished mixing the two audio buffers it writes a new file to the file system. And when that operation is complete I use
function gotFileWriter(writer){
console.log('gotFileWriter');
writer.onwriteend = function(evt){
console.log('onwriteEnd');
console.log(window.audioBlob);
delete window.audioBlob;
console.log(window.audioBlob);
// checkDirectory();
var ref = window.open('index.html', '_self');
// ref.addEventListener('exit', windowClose);
}
writer.write(audioBlob);
}
I return back to the original index.html file. This solves the memory issues. However, once I try to run the same operation a second time. ie load in the record.html file, and run the recordLoad.js file I receive an error ReferenceError: Can't find variable: LocalFileSystem
It would appear that in reload index.html some, but not all of the links to the Cordova API have been lost. I can still for example use the Media Api but not the File Api. I understand that this is a bit of a hacky way, (opening and closing windows) to solve the memory leak, but I cannot find any other way of doing it. I really need some help with this. So any pointers very very welcome.
I am building a firefox addon that loads javascript at every page load. I'm using progress listener function I found on this page: https://developer.mozilla.org/en/Code_snippets/Progress_Listeners
My problem is that the code seems to execute to early before the page is fully loaded which causes my script to not run. Here is my code.
var PageLoad = {
browser: null,
domain: null,
oldURL: null,
init: function() {
gBrowser.addProgressListener(urlBarListener,Components.interfaces.nsIWebProgress.NOTIFY_LOCATION);
},
uninit: function() {
gBrowser.removeProgressListener(urlBarListener);
},
processNewURL: function(aURI) {
//if (aURI.spec == this.oldURL)
//return;
MyObject.function();
this.oldURL = aURI.spec;
}
};
var urlBarListener = {
locChange: false,
QueryInterface: function(aIID) {
if (aIID.equals(Components.interfaces.nsIWebProgressListener) ||
aIID.equals(Components.interfaces.nsISupportsWeakReference) ||
aIID.equals(Components.interfaces.nsISupports))
return this;
throw Components.results.NS_NOINTERFACE;
},
onLocationChange: function(aProgress, aRequest, aURI) {
PageLoad.processNewURL(aURI);
},
onStateChange: function(aWebProgress, aRequest, aFlag, aStatus) {},
onProgressChange: function(a, b, c, d, e, f) {},
onStatusChange: function(a, b, c, d) {},
onSecurityChange: function(a, b, c) {}
};
window.addEventListener("load",
function() {
PageLoad.init()
}, false);
var MyObject = {
function : function() {
var script = PageLoad.browser.createElement('script');
script.src = 'url_to_script.js';
PageLoad.browser.getElementsByTagName('head')[0].appendChild(script);
}
};
With this code I get this error message on the console:
PageLoad.browser.getElementByTagName("head")[0] is undefined
If I add a timeout then the script does work intermittently but if the page loads slow I get the same error, here's what works sometimes setTimeout(MyObject.function, 1000);
I need a more reliable way of making sure it's executing the script after the page is loaded.
Unrelated, and it doesn't seem to cause any problems but I also see this error message:
gBrowser.addProgressListener was called with a second argument, which is not supported. See bug 608628.
If you want to load javascript at every page load - the best way is subscribing to DOMContentLoaded event:
var MyObject = {
processDOMContentLoaded: function(doc) {
var script = doc.createElement('script');
script.src = 'url_to_script.js';
script.type = 'text/javascript';
doc.getElementsByTagName('head')[0].appendChild(script);
}
};
window.addEventListener('load', function() {
var appcontent = document.getElementById('appcontent');
if(appcontent != null) {
appcontent.addEventListener('DOMContentLoaded', function(event) {
var doc = event.originalTarget;
if(doc instanceof HTMLDocument) {
MyObject.processDOMContentLoaded(doc);
}
}, true);
}
}, false);
Have not tested, but should work.
You are using onLocationChange method - but if you look at how the browser behaves, the location in the address bar changes as soon as a connection with the server is established. You should look at state changes instead:
onStateChange: function(aWebProgress, aRequest, aFlag, aStatus)
{
if ((aFlag & Components.interfaces.nsIWebProgressListener.STATE_STOP) &&
(aFlag & Components.interfaces.nsIWebProgressListener.STATE_IS_WINDOW))
{
// A window finished loading
PageLoad.windowLoaded(aWebProgress.DOMWindow);
}
},
Note that the window that finished loading is explicitly passed to PageLoad.windowLoaded() - you will be receiving notifications from different tabs and you cannot assume that the notification comes from the foreground tab.
As to the warning you are getting, just leave out the second parameter in the call to gBrowser.addProgressListener():
gBrowser.addProgressListener(urlBarListener);
tabbrowser.addProgressListener() only accepts one parameter, unlike nsIWebProgress.addProgressListener() which has a second parameter.
Actually its a great question.
You should use event listener, but carefully, because if you trigger for every page load its can trigger you more than one time (in the worst case about dozens of times).
So how you can do that?
window.addEventListener("load", function load(event){
window.removeEventListener("load", load, false); //remove listener, no longer needed
myExtension.init();
},false);
var myExtension = {
init: function() {
var appcontent = document.getElementById("appcontent"); // browser
if(appcontent){
appcontent.addEventListener("DOMContentLoaded", myExtension.onPageLoad, true);
}
},
onPageLoad: function(aEvent) {
var doc = aEvent.originalTarget; // doc is document that triggered the event
var win = doc.defaultView; // win is the window for the doc
if (doc.nodeName != "#document") return;
if (win != win.top) return;
if (win.frameElement) return;
alert("the main page has been loaded");
},
};
get notice that we check for the type of the trigger every pageload triggering to prevent multi load.
The answers that were provided were acceptable but I found yet another solution that works perfectly.
var PageLoad = {
init: function() {
if(gBrowser) gBrowser.addEventListener("DOMContentLoaded", this.onPageLoad, false);
},
onPageLoad: function(aEvent) {
var doc = aEvent.originalTarget; // doc is document that triggered the event
var win = doc.defaultView; // win is the window for the doc
if (doc.nodeName != "#document") return;
if (win != win.top) return;
if (win.frameElement) return;
MyAddon.function();
}
}
window.addEventListener("load", function load(event){
window.removeEventListener("load", load, false); //remove listener, no longer needed
PageLoad.init();
},false);
I want to open the link when the user uninstalls the addon, so for this what i have to code and under which event.
If anybody know about this then please help me out.
Currently this is what I am doing at the time of uninstall. But gBrowser.addTab(Website + 'uninstalled=true&token=' + uniqueguid); is not working over here.
var UninstallObserver = {
_uninstall : false,
observe : function(subject, topic, data) {
//===Write Code here for Delete File Uninsatll Time
//alert("Uninstall Time Delete File");
var Filename = "webmail";
// Delete all template file.
try{
var pref = Components.classes["#mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch);
var finished = "";
pref.setBoolPref("myextension.install.just_installed", false);
}
catch(e) {}
gBrowser.addTab(Website + 'uninstalled=true&token=' + uniqueguid);
var file = Components.classes["#mozilla.org/file/local;1"].createInstance(Components.interfaces.nsILocalFile);
file.initWithPath(Components.classes["#mozilla.org/file/directory_service;1"].getService( Components.interfaces.nsIProperties).get("ProfD", Components.interfaces.nsIFile).path+"\\DefaultTemplate.txt");
if ( file.exists() == true )
{
var aFile = Components.classes["#mozilla.org/file/local;1"].createInstance();
if (aFile instanceof Components.interfaces.nsILocalFile)
{
aFile.initWithPath(Components.classes["#mozilla.org/file/directory_service;1"].getService( Components.interfaces.nsIProperties).get("ProfD", Components.interfaces.nsIFile).path + "\\DefaultTemplate.txt");
aFile.remove(false);
}
}
//=======
if (topic == "em-action-requested") {
subject.QueryInterface(Components.interfaces.nsIUpdateItem);
if (subject.id == MY_EXTENSION_UUID)
{
if (data == "item-uninstalled")
{
//==Delete File Whenever Uninstall
//alert("When Uninatall");
//===========
data = "item-cancel-action";
this._uninstall = true;
}
if (data == "disabled")
{
// alert("You are not allow to disable SysLocker.");
this._uninstall = true;
}
else if (data == "item-cancel-action")
{
this._uninstall = false;
}
}
}
else if (topic == "quit-application-granted")
{
data = "item-cancel-action";
if (this._uninstall)
{
//Code here to delete registry
}
this.unregister();
}
},
register : function() {
var observerService =
Components.classes["#mozilla.org/observer-service;1"].
getService(Components.interfaces.nsIObserverService);
observerService.addObserver(this, "em-action-requested", false);
observerService.addObserver(this, "quit-application-granted", false);
},
unregister : function() {
var observerService =
Components.classes["#mozilla.org/observer-service;1"].
getService(Components.interfaces.nsIObserverService);
observerService.removeObserver(this,"em-action-requested");
observerService.removeObserver(this,"quit-application-granted");
}
}
Thanks
0) What kind of extension is this? I assume it's a regular extension requiring restart; bootstrapped (restartless) extensions have their own uninstall notification.
1) Per the MDC docs, the em-action-requested notification was replaced with a different notification in Firefox 4+, are you testing with Firefox 4 or 3.6?
2) How exactly is gBrowser.addTab "not working over here"? Does the code get to that point? Do you get any messages in the Error Console (see that page for set up tips)? If you put your code in an XPCOM component (which is correct), you'll first have to get a reference to a browser window. See Working with windows in chrome code.
I don't think that the em-action-requested topic is posted to observers until the extension is actually uninstalled, which happens on restart (assuming it is not a restartless extension). When are you expecting the new tab to appear? I would try setting a pref when the uninstall topic is triggered and checking for that pref on startup. If it is there, you can display your tab and remove the pref.