I have developed an add-on to communicate with a smart card. I have used winscard.dll and its functions (such as Establishment, Connecting, Transmitting).
//less-privileged scope like jsp
var element = document.createElement("MyExt1");
document.documentElement.appendChild(element);
var evt = document.createEvent("Events");
evt.initEvent("SCardConnect", true,false);
element.dispatchEvent(evt);
var CardHandle = element.getAttribute("CardHandle");
alert(CardHandle);
and
//privileged scope which exist in my add-on
.
.
.
var MyExtension1 = {
Connect : function(evt){
...
evt.target.setAttribute("CardHandle", CH.toString());
var doc = evt.target.ownerDocument;
var AnswerEvt = doc.createElement("SCardConnect");
doc.documentElement.appendChild(AnswerEvt);
var event = doc.createEvent("HTMLEvents");
event.initEvent("ConnectEvent",true,false);
AnswerEvt.dispatchEvent(event);
}
}
.
.
.
document.addEventListener("SCardConnect", function(e){myExtension1.Connect(e);}, false, true);
After a small introduction, this is my problem:
When I install the add-on in Firefox and debug the code step by step through F10 it works fine, however if I want to run the external script without interruption (without debugging), it returns null when I get attributes.
This is an event-based approach to call an add-on function from an external script function. There is another approach that used export function which I get following problem:
https://stackoverflow.com/questions/32450103/calling-a-firefox-add-on-function-from-an-external-javascript-file
You might want to move 'var CardHandle = element.getAttribute("CardHandle");' into a new function and check if its value has been valid or not in specified intervals.
var varTimer = setInterval(function(){ myTimer() }, 1000);
function myTimer() {
var CardHandle = element.getAttribute("CardHandle");
if(CardHandle is valid) stopTimer();
}
function stopTimer() {
clearInterval(varTimer);
}
Related
I'm writing a WP8.1-App in JavaScript/HTML that needs a working camera.
My mediaCapture is set up and working. So I tried to do the focus:
var focusControl = mediaCapture.videoDeviceController.focusControl;
focusControl.focusAsync().then(function () { ..... });
But here it fails with a catastrophic failure in this line. Same, if I remove the .then-part.
I read a bit on the internet and wanted to check my focusSettings to make sure everything is set up fine. But this:
var focusSettings = new Windows.Media.Devices.FocusSettings();
var modeContinuous = Windows.Media.Devices.FocusMode.continuous;
var distanceHyperfocal = Windows.Media.Devices.ManualFocusDistance.hyperfocal;
var rangeFull = Windows.Media.Devices.AutoFocusRange.fullRange;
focusSettings.distance = distanceHyperfocal;
focusSettings.mode = modeContinuous;
focusSettings.autoFocusRange = rangeFull;
and this:
var focusSettings = new Windows.Media.Devices.FocusSettings();
focusSettings.distance = focusControl.supportedFocusDistances[0];
focusSettings.mode = focusControl.supportedFocusModes[0];
focusSettings.autoFocusRange = focusControl.supportedFocusRanges[0];
both crash in this line:
var focusControl = mediaCaptureMgr.videoDeviceController.focusControl;
focusControl.configure(focusSettings);
It says: JavaScript runtime error: The application called an interface that was marshalled for a different thread. But afaik there is no dispatcher in JavaScript so I can't push it to the UI thread (if it is not there already..).
What am I doing wrong?
The default focusSettings sets it to focus once. I wanted to set continuous or at least autofocus everytime before I capture a photo.
I'm running a script on Facebook that requires me to get the IDs of people in my "friends" window (this might not be the most efficient way to accomplish this specific task, but since I'd like to know how to do this in general it's a good example).
This means that if I have more than a small number of friends I have to scroll down for Facebook to add them to the page.
I've added logic that scrolls the page down to the footer, but I don't know how to force my function that grabs the IDs to run after the content loads.
For now, I've resorted to using setTimeout for a few seconds - obviously, this isn't guaranteed to at the appropriate time, so I'd like to know how to do this properly:
var k;
function doit(){
k = document.getElementsByClassName("_698");
var g= Array.prototype.slice.call(k);
confirm(g.length);
// the confirm is just to make sure it's working
// (if i don't use setTimeout it'll return a smaller number
// since not all the friends were included)
}
window.addEventListener("load", function(){
document.getElementById( "pageFooter" )
.scrollIntoView();setTimeout(doit,3000);
});
Crayon Violent details how to accomplish this in his answer to JavaScript detect an AJAX event. The trick is to hook the underlying XMLHttpRequest object in order to detect when a request is sent.
I've re-written the logic there a bit to make it more suitable for your needs:
//
// Hooks XMLHttpRequest to log all AJAX requests.
// Override ajaxHook.requestCompleted() to do something specific
// in response to a given request.
//
var ajaxHook = (function()
{
// we're using a self-executing function here to avoid polluting the global
// namespace. The hook object is returned to expose just the properties
// needed by client code.
var hook = {
// by default, just logs all requests to the console.
// Can be overridden to do something more interesting.
requestCompleted: function(xmlHttp, url, method) { console.log(url); }
};
// hook open() to store URL and method
var oldOpen = XMLHttpRequest.prototype.open;
XMLHttpRequest.prototype.open = function(method, url)
{
this.hook_method = method;
this.hook_url = url;
oldOpen.apply(this, arguments);
}
// hook send() to allow hooking onreadystatechange
var oldSend = XMLHttpRequest.prototype.send;
XMLHttpRequest.prototype.send = function()
{
var xmlhttp = this;
//hook onreadystatechange event to allow processing results
var oldReadyStateChange = xmlhttp.onreadystatechange;
xmlhttp.onreadystatechange = function()
{
oldReadyStateChange.apply(xmlhttp, arguments);
if ( this.readyState === 4 ) // completed
{
hook.requestCompleted(xmlhttp,
xmlhttp.hook_url, xmlhttp.hook_method);
}
};
oldSend.apply(this, arguments);
};
return hook;
})();
With this bit of code loaded in your userscript, you can then implement your logic as follows:
var k;
function doit()
{
k = document.getElementsByClassName("_698");
var g= Array.prototype.slice.call(k);
confirm(g.length);
}
window.addEventListener("load", function()
{
ajaxHook.requestCompleted = function(xmlhttp, url, method)
{
// is this the request we're interested in?
// (Facebook appears to load friends from a URL that contains this string)
if ( /AllFriendsAppCollectionPagelet/.test(url) )
{
// Facebook defers rendering the results here,
// so we just queue up scraping them until afterwards
setTimeout(doit, 0);
}
};
// trigger loading of more friends by scrolling the bottom into view
document.getElementById( "pageFooter" )
.scrollIntoView();
});
Is there a way to detect if NaCl is available on the current browser?
It seems that checking for chrome.app.isInstalled turns into false positive on some non-Chrome browsers
You can check if the browser handles the NaCl mime type. E.g.:
navigator.mimeTypes['application/x-nacl'] !== undefined.
Similarly, for PNaCl, you can check for 'application/x-pnacl'.
You can check for Chrome and a particular version of Chrome like this:
var have_nacl = false;
var have_pnacl = false;
var index = navigator.userAgent.indexOf('Chrome');
if (index != -1) {
var version = parseFloat(navigator.userAgent.substring(index + 7));
if (31 <= version) have_pnacl = true;
if (14 <= version) have_nacl = true;
}
However, this does not tell the full story. Versions 31+ have PNaCl and it's enabled by default. NaCl is only enabled by default for apps in the Chrome store so you would still need to test if NaCl is enabled. One way to do this is to set a watchdog timer then try to load an NaCl module and capture the load event. In the load event clear the watchdog timer. For example:
var watchdog;
var watchdog_time;
function watchdog_timeout() {
alert('NaCl module failed to load');
}
function watchdog_clear() {
clearTimeout(watchdog);
}
function watchdog_set(time) {
watchdog_time = time;
watchdog = setTimeout(watchdog_timeout, time);
}
watchdog_set(5000); // Timeout in 5 sec
var module = document.getElementById('module'); // Use your module's ID
module.addEventListener('load', function () {
watchdog_clear();
alert('NaCl module loaded');
}, true);
// Inject the module, where module.nmf is your NMF file.
module.innerHTML = '<embed src="module.nmf" type="application/x-nacl"/>';
This requires that you have something like the following somewhere in your HTML:
<div id="module"></div>
If your module takes awhile to download you might also want to capture the loadstart and progress events and extend the watchdog time.
function watchdog_extend() {
watchdog_clear();
watchdog_set(watchdog_time);
}
module.addEventListener('loadstart', watchdog_extend, true);
module.addEventListener('progress', watchdog_extend, true);
Boy-oh-boy do I hate external interface. I have a video player that utilizes external interface to control the flash object and to allow the flash object to pass messages to the same javascript. For a time it worked well in all browsers. Then a few days ago i went to go test it in all browsers before i moved the project out of development, and found that the application broke in internet explorer 9. The following error appeared in the console:
SCRIPT16389: Could not complete the operation due to error 8070000c.
jquery.min.js, line 16 character 29366
My javascript file is really long but here are the important parts. All my actions are contained in an object that i created. Inside one of my methods i have the following lines:
var that = this;
that.stop();
here are all the methods that get called as a result of that method:
this.stop = function(){
var that = this;
console.log('stop called');
that.pause();
that.seek(0);
that.isPlaying = false;
console.log('stop finished');
};
this.pause = function(){
var that = this;
console.log('pause called');
if(that.player == 'undefined' || that.player == null){
that.player = that.GetMediaObject(that.playerID);
}
that.player.pauseMedia(); //external interface call
that.isPlaying = false;
console.log('pause finished');
};
this.seek = function(seek){
var that = this;
console.log('seek called');
if(that.player == 'undefined' || that.player ==null){
console.log("player="+that.player+". resetting player object");
that.player = that.GetMediaObject(that.playerID);
console.log("player="+that.player);
}
that.player.scrubMedia(seek); //external interface call
console.log('seek finished');
};
//this method returns a reference to my player. This method is call once when the page loads and then again as necessary by all methods that make external interface calls
this.GetMediaObject = function(playerID){
var mediaObj = swfobject.getObjectById(playerID);
console.log('fetching media object: ' +mediaObj );
//if swfobject.getObjectById fails
if(typeof mediaObj == 'undefined' || mediaObj == null){
console.log('secondary fetch required');
var isIE = navigator.userAgent.match(/MSIE/i);
mediaObj = isIE ? window[playerID] : document[playerID];
}
return mediaObj;
};
Here's the output from my console.log statments:
LOG: fetching media object: [object HTMLObjectElement]
LOG: video-obj-1: ready
LOG: stop called
LOG: pause called
LOG: pause finished
LOG: seek called
LOG: player=[object HTMLObjectElement]
SCRIPT16389: Could not complete the operation due to error 8070000c.
jquery.min.js, line 16 character 29366
The interesting thing is that it appears that the first external interface call 'that.player.pauseMedia()' doesn't have any issue, but the subsequent call to 'that.player.scrubMedia(0)' fails. Another odd thing is that it points to jquery as the source of the error, but there's no call to jquery in those functions.
Here's what i know it's not. It is not an issue where my timing is off. The last line of my actionscript sends a message to the javascript when the flash object has completely loaded. Also i set the parameter 'allowScriptAccess' to 'always' so it's not that either. The actionscript file we use has been used in previous projects so i am 90% certain that that is not the issue.
here's my actionscript anyways. I didn't write actionscript and i'm not too familiar with the language but I tried to put in the parts that seemed most pertinent to my application:
flash.system.Security.allowDomain("*.mydomain.com");
import flash.external.ExternalInterface;
// variables to store local information about the current media
var mediaEmbedServer:String = "www";
var mediaPlayerID:String;
var mediaFile:String;
var mediaDuration:Number;
// variables to be watched by actionscript and message javascript on changes
var mediaPositions:String = "0,0"; // buffer position, scrub position
var mediaStatus:String;
var netStreamClient:Object = new Object();
netStreamClient.onMetaData = metaDataHandler;
netStreamClient.onCuePoint = cuePointHandler;
var connection:NetConnection;
var stream:NetStream;
var media:Video = new Video();
// grab the media's duration when it becomes available
function metaDataHandler(info:Object):void {
mediaDuration = info.duration;
}
function cuePointHandler(info:Object):void {
}
connection = new NetConnection();
connection.addEventListener(NetStatusEvent.NET_STATUS, netStatusHandler);
connection.addEventListener(SecurityErrorEvent.SECURITY_ERROR, securityErrorHandler);
try {
var paramName:String;
var paramValue:String;
var paramObject:Object = LoaderInfo(this.root.loaderInfo).parameters;
for (paramName in paramObject) {
paramValue = String(paramObject[paramName]);
switch (paramName){
case "server":
mediaEmbedServer = paramValue;
break
case "playerID":
mediaPlayerID = paramValue;
break
}
}
} catch (error:Error) {
}
if (mediaEmbedServer == "dev" || mediaEmbedServer == "dev2"){
connection.connect("rtmp://media.developmentMediaServer.com/myApp");
} else {
connection.connect("rtmp://media.myMediaServer.com/myApp");
}
function securityErrorHandler(event:SecurityErrorEvent):void {
trace("securityErrorHandler: " + event);
}
function connectStream():void {
stream = new NetStream(connection);
stream.soundTransform = new SoundTransform(1);
stream.addEventListener(NetStatusEvent.NET_STATUS, netStatusHandler);
stream.client = netStreamClient;
media.attachNetStream(stream);
media.width = 720;
media.height = 405;
addChild(media);
}
function netStatusHandler(stats:NetStatusEvent){
switch (stats.info.code){
case "NetConnection.Connect.Success":
connectStream();
break;
case "NetConnection.Call.BadVersion":
case "NetConnection.Call.Failed":
case "NetConnection.Call.Prohibited":
case "NetConnection.Connect.AppShutdown":
case "NetConnection.Connect.Failed":
case "NetConnection.Connect.InvalidApp":
case "NetConnection.Connect.Rejected":
case "NetGroup.Connect.Failed":
case "NetGroup.Connect.Rejected":
case "NetStream.Connect.Failed":
case "NetStream.Connect.Rejected":
case "NetStream.Failed":
case "NetStream.Play.Failed":
case "NetStream.Play.FileStructureInvalid":
case "NetStream.Play.NoSupportedTrackFound":
case "NetStream.Play.StreamNotFound":
case "NetStream.Seek.Failed":
case "NetStream.Seek.InvalidTime":
// report error status and reset javascriptPlay
clearInterval(progressInterval);
messageStatus("error");
break;
default:
// check time through file to determine if media is over
if (stream.time > 0 && stream.time >= (mediaDuration - .25)){
// reset media if it has ended
clearInterval(progressInterval);
stream.play(mediaFile, 0, 0);
messageStatus("finished");
}
}
};
var progressInterval:Number;
// respond to a play/pause request by playing/pausing the current stream
function pauseMedia(){
clearInterval(progressInterval);
if (mediaStatus == 'playing'){
stream.pause();
messageStatus("paused");
}
};
ExternalInterface.addCallback( "pauseMedia", pauseMedia );
// respond to a scrub request by seeking to a position in the media
function scrubMedia(newPosition){
clearInterval(progressInterval);
if (mediaStatus == "playing"){
stream.pause();
messageStatus("paused");
}
stream.seek(newPosition * mediaDuration);
var positionSeconds = newPosition * mediaDuration;
messagePositions(positionSeconds+","+positionSeconds);
};
ExternalInterface.addCallback( "scrubMedia", scrubMedia );
ExternalInterface.call("MediaPlayerReady", mediaPlayerID);
Sounds like an undefined expando property which may be caused by a jQuery IE9 bug. The best way to debug it is to remove the userAgent test and replace it with a check for the object element, such as:
document.getElementsByTagName("object")[0].outerHTML
to see whether the ID attribute is being changed after the first click by jQuery.
I had this problem using JPEGCam, which also uses flash's external interface. My webcam control was being loaded dynamically within a div, and would then throw this error in IE (not firefox or chrome). After moving the initialization of my flash control to document.ready in the parent page, then hiding/showing/moving the control as needed, i was able to work around this exception.
Hope that helps.
Thanks to everyone in advance -
I need to load a preference before any windows are loaded at startup. Below is some /component code I have been working with. The SetPreference method seems to fail when it is called (nothing executes afterwords either) - I am assuming because the resources that it needs are not available at the time of execution...or I am doing something wrong. Any suggestions with this code or another approach to setting a preference at startup?
Thanks again,
Sam
For some reason the code formatting for SO is not working properly - here is a link to the code as well - http://samingrassia.com/_FILES/startup.js
Components.utils.import('resource://gre/modules/XPCOMUtils.jsm');
const Cc = Components.classes;
const Ci = Components.interfaces;
const ObserverService = Cc['#mozilla.org/observer-service;1'].getService(Ci.nsIObserverService);
function MyStartupService() {};
MyStartupService.prototype = {
observe : function(aSubject, aTopic, aData) {
switch (aTopic) {
case 'xpcom-startup':
this.SetPreference("my.extension.is_running", "false");
break;
case 'app-startup':
this.SetPreference("my.extension.is_running", "false");
ObserverService.addObserver(this, 'final-ui-startup', false);
break;
case 'final-ui-startup':
//make sure is_running is set to false
this.SetPreference("my.extension.is_running", "false");
ObserverService.removeObserver(this, 'final-ui-startup');
const WindowWatcher = Cc['#mozilla.org/embedcomp/window-watcher;1'].getService(Ci.nsIWindowWatcher);
WindowWatcher.registerNotification(this);
break;
case 'domwindowopened':
this.initWindow(aSubject);
break;
}
},
SetPreference : function(Token, Value) {
var prefs = Components.classes["#mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefService);
var str = Components.classes["#mozilla.org/supports-string;1"].createInstance(Components.interfaces.nsISupportsString);
str.data = Value;
prefs.setComplexValue(Token, Components.interfaces.nsISupportsString, str);
//save preferences
var prefService = Components.classes["#mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefService);
prefService.savePrefFile(null);
},
initWindow : function(aWindow) {
if (aWindow != '[object ChromeWindow]') return;
aWindow.addEventListener('load', function() {
aWindow.removeEventListener('load', arguments.callee, false);
aWindow.document.title = 'domwindowopened!';
// for browser windows
var root = aWindow.document.documentElement;
root.setAttribute('title', aWindow.document.title);
root.setAttribute('titlemodifier', aWindow.document.title);
}, false);
},
classDescription : 'My Startup Service',
contractID : '#mystartupservice.com/startup;1',
classID : Components.ID('{770825e7-b39c-4654-94bc-008e5d6d57b7}'),
QueryInterface : XPCOMUtils.generateQI([Ci.nsIObserver]),
_xpcom_categories : [{ category : 'app-startup', service : true }]
};
function NSGetModule(aCompMgr, aFileSpec) {
return XPCOMUtils.generateModule([MyStartupService]);
}
To answer your real question, which is
I have code that loads on every window load and I need to make sure that only gets executed once every time firefox starts up.
..you should just use a module, in the load handler that you wish to execute once, check a flag on the object exported from (i.e. "living in") the module, then after running the code you need, set the flag.
Since the module is shared across all windows, the flag will remain set until you close Firefox.
As for your intermediate problem, I'd suggest wrapping the code inside observe() in a try { ... } catch(e) {dump(e)} (you'll need to set a pref and run Firefox in a special way in order to see the output) and check the error returned.
I guess xpcom-startup and app-startup is too early to mess with preferences (I think you need a profile for that), note that you don't register to get xpcom-startup notification anyway. You probably want to register for profile-after-change instead.