I was wondering if it is possible to track user location in a React Native application without using Google APIs.
In reality I'm using the Google API, but only to get the current location in this way
Geolocation.getCurrentPosition((position) => {
This function is placed inside a setInterval that every 3 seconds gets the new coordinates. The issue that I'm facing is that if I'm stopped the coordinates can be not precise and I store in the state array a value that will break the distance calculation.
Example of coordinates stored
LOG [17.9443, 40.633]
LOG [17.9443, 40.633]
LOG [17.9442, 40.633]
LOG [17.9442, 40.633]
LOG [17.9443, 40.633]
LOG [17.9443, 40.633]
LOG [17.9443, 40.633]
In this case, despite have being stopped, the calculation would give 16 meters of walk.
How the calculation is made?
I'm using the turf library. I store all points in a state array. Then use the points to generate runtime a turf.lineString and in the end I calculate the length (meters) of the lineString.
setTrackPoints((prevState) => [...prevState, turf.truncate(turf.flip(currentCoordinates),{precision: 4})]);
let lineString = turf.lineString(trackPoints, { name: 'tracked' })
turf.length(lineString, {units: 'meters'}).toFixed(2)
What can be the right way to get rid of dirty data? Reducing the precision to 3 would provide a distance that is not enough precise.
Related
For a mental health app project, I need to intercept the startup of specific apps (like Instagram) and check if they used instagram the n-th time, possibly opening a questionair etc.
Searching for a solutions online, I came across the "android.app.usage" API. I could not get my around how to use this.
Do I need a for every running background service which does active polling with the usage api?
Or is their a way to say "run this code or start this app/service when appXY launches"?
Looking forward to any kind of input :)
Greetings Pascal
You can't listen out for an "app is being opened" intent unfortunately, Android doesn't support it. Your approach is likely the best workaround, to state it explicitly:
Have a foreground service running (so it is less likely to be killed by the OS) at all times.
Check regularly the currently running app, and see if it's the one you're trying to look for.
If this is different to last time you checked, do whatever you need to. Perhaps this will include keeping track of last time the app was opened, how many times it's been opened etc.
As a warning however, the OS won't really like this, and there's likely to be an impact on battery life. Whatever you do, make sure this check isn't happening when the screen is off, happening as infrequently as possible, and doesn't include any unnecessary computation, otherwise the user will quickly notice the negative impact.
Here's an extract from an article that looks like it'll be able to fetch the latest app even on later versions:
var foregroundAppPackageName : String? = null
val currentTime = System.currentTimeMillis()
// The `queryEvents` method takes in the `beginTime` and `endTime` to retrieve the usage events.
// In our case, beginTime = currentTime - 10 minutes ( 1000 * 60 * 10 milliseconds )
// and endTime = currentTime
val usageEvents = usageStatsManager.queryEvents( currentTime - (1000*60*10) , currentTime )
val usageEvent = UsageEvents.Event()
while ( usageEvents.hasNextEvent() ) {
usageEvents.getNextEvent( usageEvent )
Log.e( "APP" , "${usageEvent.packageName} ${usageEvent.timeStamp}" )
}
I have a GtkTreeView object that uses a GtkListStore model that is constantly being updated as follows:
Get new transaction
Feed data into numpy array
Convert numbers to formatted strings, store in pandas dataframe
Add updated token info to GtkListStore via GtkListStore.set(titer, liststore_cols, liststore_data), where liststore_data is the updated info, liststore_cols is the name of the columns (both are lists).
Here's the function that updates the ListStore:
# update ListStore
titer = ls_full.get_iter(row)
liststore_data = []
[liststore_data.append(df.at[row, col])
for col in my_vars['ls_full'][3:]]
# check for NaN value, add a (space) placeholder is necessary
for i in range(3, len(liststore_data)):
if liststore_data[i] != liststore_data[i]:
liststore_data[i] = " "
liststore_cols = []
[liststore_cols.append(my_vars['ls_full'].index(col) + 1)
for col in my_vars['ls_full'][3:]]
ls_full.set(titer, liststore_cols, liststore_data)
Class that gets the messages from the websocket:
class MyWebsocketClient(cbpro.WebsocketClient):
# class exceptions to WebsocketClient
def on_open(self):
# sets up ticker Symbol, subscriptions for socket feed
self.url = "wss://ws-feed.pro.coinbase.com/"
self.channels = ['ticker']
self.products = list(cbp_symbols.keys())
def on_message(self, msg):
# gets latest message from socket, sends off to be processed
if "best_ask" and "time" in msg:
# checks to see if token price has changed before updating
update_needed = parse_data(msg)
if update_needed:
update_ListStore(msg)
else:
print(f'Bad message: {msg}')
When the program first starts, the updates are consistent. Each time a new transaction comes in, the screen reflects it, updating the proper token. However, after a random amount of time - seen it anywhere from 5 minutes to over an hour - the screen will stop updating, unless I change the focus of the window (either activate or inactive). This does not last long, though (only enough to update the screen once). No other errors are being reported, memory usage is not spiking (constant at 140 MB).
How can I troubleshoot this? I'm not even sure where to begin. The data back-ends seem to be OK (data is never corrupted nor lags behind).
As you've said in the comments that it is running in a separate thread then i'd suggest wrapping your "update liststore" function with GLib.idle_add.
from gi.repository import GLib
GLib.idle_add(update_liststore)
I've had similar issues in the past and this fixed things. Sometimes updating liststore is fine, sometimes it will randomly spew errors.
Basically only one thread should update the GUI at a time. So by wrapping in GLib.idle_add() you make sure your background thread does not intefer with the main thread updating the GUI.
I'm working with RabbitMQ instances hosted at CloudAMQP. I'm calling the management API to get detailed queue statistics. About 1 in 10 calls to the API return invalid numbers.
The endpoint is /api/queues/[vhost]/[queue]?msg_rates_age=600&msg_rates_incr=30. I'm looking for average message rates at 30 second increments over a 10 minute span of time. Usually that returns valid data for the stats I'm interested in, e.g.
{
"messages": 16,
"consumers": 30,
"message_stats": {
"ack_details": {
"avg_rate": 441
},
"publish_details": {
"avg_rate": 441
}
}
}
But sometimes I get incorrect results for one or both "avg_rate" values, often 714676 or higher. If I then wait 15 seconds and call the same API again the numbers go back down to normal. There's no way the average over 10 minutes jumps by a multiple of 200 and then comes back down seconds later.
I haven't been able to reproduce the issue with a local install, only in production where the queue is always very busy. The data displayed on the admin web page always looks correct. Is there some other way to get the same stats accurately like the UI?
redux-persist has been working perfectly for me with smaller size state trees, but trying to use it on bigger ones I'm running into these errors when relaunching the app:
redux-persist/getStoredState: Error restoring data for key: pos Error: Couldn't read row 0, col 0 from CursorWindow. Make sure the Cursor is initialized correctly before
Couldn't read row 0, col 0 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
Error: Couldn't read row 0, col 0 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
I've tried things like this in MainApplication.java - onCreate method:
*long size = 50L * 1024L * 1024L; // 50 MB
com.facebook.react.modules.storage.ReactDatabaseSupplier.getInstance(getApplicationContext()).setMaximumSize(size)*
But it seems not work.
Thanks in advance
Looks like you have hit the maximum size limit for storing data in Android AsyncStorage which is currently 6MB.
I can see that you increased the AsyncStorage size to 50MB but however, it is still possible that your data's size is greater than 50MB. You can use the following plugin which makes use of fileSystem instead of AsyncStorage to persist your Redux state:
https://www.npmjs.com/package/redux-persist-filesystem-storage
This way you wouldn't have to worry about AsyncStorage size limit.
I'm about to release my App on IOS that uses Nuance Dragon Mobile SDK. I'm signed up for the "Silver" plan, which allows me 20 transactions per day.
My question is, does anyone know what error is returned by Nuance, when the limit is exceeded? I'm concerned, because I am filtering out:
error.code == 5 // Because this fires whenever I interrupt running speech
error.code == 1 // Because after interrupting speech, the first time I restart, it cuts off
// before finished, so I automatically start again, so as not to trouble the user to do so
I figure if Nuance returns an error different from these, I'll allow it to pass through, and be able to alert the user that they've reached their daily limit.
I think the following gives the possible errors:
extern NSString * const SKSpeechErrorDomain;
enum {
SKServerConnectionError = 1,
SKServerRetryError = 2,
SKRecognizerError = 3,
SKVocalizerError = 4,
SKCancelledError = 5,
};
It seems likely to me that it's the SKServerConnectionError that would be fired. In that case, I need to come up with a different strategy. If I could figure out what's going on with the restart issue I wouldn't have to filter out that error. Plus, when I automatically restart these false starts, I'm probably racking up my transaction count, which is unfortunate.
Anybody have experience with this aspect of the Nuance SDK for IOS?