Close cefpython clientand restart a new one - python-3.x

During the application flow I would like to close cefpython running client and open a new one; I've this function
....
while True:
settings = {...}
settings2= {...}
cef.Initialize(settings=settings)
self.BROWSER = cef.CreateBrowserSync(url=url,
window_title="Tutorial",
browserSettings=settings2)
bindings = cef.JavascriptBindings(bindToFrames=False,
bindToPopups=False)
bindings.SetFunction("backend", func)
self.BROWSER.SetJavascriptBindings(bindings)
cef.MessageLoop()
cef.Shutdown()
and in another function I have this call
self.BROWSER.CloseBrowser(True)
Browser start on first run and is closed but it does not restart. If I comment the line
...
cef.MessageLoop()
#cef.Shutdown()
in the first function the browser does restart but it get stuck and I can't use it.
Thanks in advance.

Functions like cef.Initialize and cef.Shutdown can be called only once during app lifetime. You also shouldn't call cef.MessageLoop multiple times. Your code while True doesn't make much sense, because you do not give browsers time to initialize and load. You should use events like LoadHandler.OnLoadEnd or OnLoadingStateChange or others depending on what you're trying to accomplish.

Related

How to debug a python websocket script that uses `.run_forever()` method (infinite event loop)

I'm coding a script that connects to the Binance websocket and uses the .run_forever() method to constantly get live data from the site. I want to be able to debug my code and watch the values of variables as the change but I'm not sure how to do this as the script basically hangs on the line with the .run_forever() method, because it is an infinite event loop. This is by design as I want to continuously get live data (it receives a message approximately every second), but I can't think of a way a good way to debug it.
I'm using VSCode and here are some snippets of my code to help understand my issue. The message function for the websocket is just a bunch of technical analysis and trade logic, but it is also the function that contains all the changing variables that I want to watch.
socket = f"wss://stream.binance.com:9443/ws/{Symbol}#kline_{interval}"
def on_open(ws):
print("open connection")
def on_message(ws, message):
global trade_list
global in_position
json_message = json.loads(message)
candle = json_message['k'] # Accesses candle data
...[trade logic code here]...
def on_close(ws):
print("Websocket connection close")
# ------------------------- Define a websocket object ------------------------ #
ws = websocket.WebSocketApp(socket, on_open=on_open, on_message=on_message, on_close=on_close)
ws.run_forever()
If more code is required to answer the question, then I can edit this question to include it (I'm thinking if you would like to have an idea of what variables I want to look at, I just thought it would be easier and simpler to show these parts).
Also, I know using global isn't great, once I've finished (or am close to finishing) the script, I want to go and tidy it up, I'll deal with it then.
I'm a little late to the party but the statement
websocket.enableTrace(True)
worked for me. Place it just before you define your websocket object and it will print all traffic in and out of the websocket including any exceptions that you might get as you process the messages.

Bukkit/Spigot - How to wait until BukkitRunnable is finished

In my onDisbale() method in my Main class I have a loop which creates and starts new BukkitRunnables.
I'm getting a error in console: org.bukkit.plugin.IllegalPluginAccessException: Plugin attempted to register task while disabled I need to somehow wait in my onDisable() method until all the BukkitRunnables I create in the loop are finished. How to do that?
My code looks like this:
#Override
public void onDisable() {
for (Player p : Bukkit.getOnlinePlayers()) {
new PlayerDataSaverRunnable().runTaskAsynchronously(this);
}
}
The onDisable method is the very last thing that gets called before your plugin is disabled and the server shuts down. So, as the error message says, you unfortunately can't schedule any new tasks in the onDisable function.
You mentioned in a comment that you were trying to write to a file in the plugins folder, and under normal circumstances you'd want to do that asynchronously. But, because onDisable only ever gets called when the server is shut down (or when the entire server is reloaded with /reload), it's perfectly fine to run code here that blocks the main thread and could potentially take a few seconds to run — in the case of a shutdown, by the time this method gets called, all the players will have already been kicked off the server, and so there's no "lag" to complain about. If your plugin is super advanced and has to save a bunch of stuff, I don't think any server owners would complain even if it took 10 or so seconds to disable.
Of course, you would have to be saving something crazy for it to take a whole 10 seconds to save. More than likely, most files will save in just a few milliseconds.
If you're really dead-set on disabling the plugin as fast as possible, you might consider having some async task that runs every 5 minutes or so and auto-saves the files. Then, in onDisable, you could only save files that changed since the auto-saver was last run. That's a good practice anyways, just incase the server crashes or the power goes out and the onDisable method doesn't get a chance to run. But, then again, I would still recommend that you save everything in the onDisable method (that's what I do for all of my plugins, as well), even if it will take a few seconds and block the main thread, just so you can be 100% sure that everything gets saved correctly.

Why doesn't ElectronJS simply exit when given a blank index.js file?

I'm trying to understand the Electron Main process. I'm confused about something.
Try this:
% touch blank.js
% electron blank.js
You will notice that electron does not exit. Since no 'app' has been created, it isn't clear to me why the process is sticking around, and why I need to call process.exit from blank.js to terminate. The documentation is a bit thin in describing main/browser extensions to process.
Say I have a typical electron app:
await app.whenReady();
const win = new BrowserWindow();
await win.loadUrl("https://google.com");
The window is created and the main method exits. Nothing else is awaiting anything. Electron doesn't exit in this case, because it doesn't make sense to since we're now just waiting on the user to interact with the window.
The things that should trigger an exit are the remaining window closing (window-all-closed event), or an explicit app.quit() type of command.
Now I guess you might say that this is different since a window actually got created, but how would Electron know that this will happen? For how long must it wait until it can be sure that no window will be created?
Establishing a rule like "the main method must await the window creation" seems overly-restrictive to me, so Electron just assumes that it might happen later or it might not, but until it's told to exit, it'll wait.
Ultimately, someone on the Electron team could give a more accurate answer, but this is my best guess.

Cannot get QWindow::fromWinId to work properly

My Qt 5.9 program (on X11 Linux) launches other applications, using QProcess.
I would like to have control over windows these applications spawn, so I obtain their winId value and use QWindow::fromWinId to get a QWindow instance.
The problem is these instances are invalid and do not represent the window they are supposed to.
If I check the winId values using xwininfo, the correct information is returned, so I know they are good.
What am I doing wrong?
Edit: An example won't help much, but here goes:
QProcess *process=new QProcess(this);
...
process.open()
... // wait until window appears
WId winId=PidToWid(process->processId()); // this function returns the Window ID in decimal format. I test this with xwininfo, it's always correct
...
QWindow *appWindow=QWindow::fromWinId(winId);
... And that's basically it. appWindow is a valid QWindow instance, but it does not relate to the actual window in any way. For example, if I close() it, it returns true but the window does not close.
Even if I provide a wrong WId on purpose, the end result is the same.
This is not proper solution with explanation why it should work, however it may be helpful for somebody...
I had the same issue with my application when I switched from Qt4 QX11EmebeddedContainer to Qt5 implementation using QWindow. What I did to resolve / fix this issue was following:
Client application:
widget->show(); //Widget had to be shown
widget->createWinId();
sendWinId(widget->winId()); //Post window handle to master app where is constructed container
Master application:
QWindow* window = QWindow::fromWinId(clientWinId);
window->show(); //This show/hide toggle did trick in combination with show in client app
window->hide();
QWidget* container = QWidget::createWindowContainer(window, parentWindowWidget);
After this I was able to control window properly through QWidget container.

nightwatch - check for popup window, after each click event

Is there a way in nightwatch to check whether a popup window appears after each click event?
I have a problem that randomly an error message appear and I don't want to write for each click event the same callback function.
I have already tried out the after and afterEach commands in the Global.js but then the commands will only run after the whole test suite.
I also have tried it local within a test file, although it also does not cover all single click events, even though the official website writes "... while beforeEach and afterEach are ran before and after each testcase (test step)"?
Solution I'm looking for:
.waitForElementVisible('selector')
.click('selector')
.click('selector')
Solution I have come up with so far:
.waitForElementVisible('selector')
.click('selector', isPresent)
.click('selector', isPresent)
isPresent as a callback function, which does the checking and close the popup window if it appears.
Is there another way to write a function (with or without after and/or forEach), so that it will be called after each click event or after each command. Thus, I don't have to write the isPresent repetitive code?
You can insert something like this in your page object file:
var popupCommand = {
popupCheck:function(){
return this.waitForElementVisible('selector', 5000)
.click('selector', isPresent)
.click('selector', isPresent)
},
module.exports = {
commands:[popupCommand],
elements:{
firstElement: {selector: 'xpath',locateStrategy: 'xpath'},
secondElement: {selector: 'css'},
}
}
Where 'popupCommand' will be the name of your page object file, for example 'Popup'. And also you will have to insert your isPresent callback function here so you can use it.
I did my best to explain you as much as possible what and how to do that :)
you should yse .switchWindow() method.
Why don't you write your own custom command specific for that case, so that way you will avoid repetitive code?

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