If I had to build my own check-in feature from scratch, how would I go about it? I was thinking that once a location is determined using corelocations, I can add that location co-ordinate and timestamp to a database in some server. Now once one of my friends check-in close to that location, there can be a query to the database to figure out all check-ins around that location and around that timestamp. Is that how they implement this feature?
Those services use the current location (that you could get via CoreLocation or otherwise) in order to determine which venues to show near the user. Note that they usually have a database of business venues and the user selects the one they are actually and perform the checkin.
So, in order to figure out "who you are hanging out with", they only have to see who has checked in in that specific location, around that timestamp.
Note that the whole thing could have been implemented without location services and geographical coordinates - just choose from a list! Now, with location services, you can help the user search for the place quickly.
Related
I am trying to calculate how many miles away the user is from another user. Like on Tinder.
I am using Firebase to store all of the users data related to the app.
What would be the most secure way to do this without storing the actual users current location?
You need to get the current location, and after calculating the distance or after the user logs out, delete the location from the database. That is the only way to do it.
Note that this will work only if both users are online at the same time.
I am in the process of building an app, for the record I am using the code from the ECSlidingView controller. I would like for my app to use the GPS to pull data from my web interface letting the user know that they can do certain things at a given location. So for example, I have a user go to a store and lets say I want them to make a payment at that location, it will given them that option. Or if the store doesn't offer payment through the app, I disable that. What would be a good way to go about this?
You could try using CoreLocation but you might have trouble getting accurate location inside (it will most probably use wifi or cellular info so the accuracy might not be what you expect). Then, when you get the location, issue a request to your service passing latitude and longiude you receive from CoreLocation. There, you should search by location to retrieve possible matches - consider returning muliple store infos for nearby stores due to the accuracy issues.
Ok... maybe forbidden by Apple, but assuming this is permitted. What would be the best way to get the current location (not difficult) and posting it to a web service (also not much of a challenge). The app is for an artist who wants people to see where he is at the moment. Personally, I wouldn't want people to know where I am 24/7 but that's performance art I guess. An exact location is not wanted but a town or area would be preferred. I could modify the string when it gets to the server and make it more vague by rounding the LOG and LAT.
The app the fans would use would retrieve his current location from the server and update the map view with a location.
I suppose one way would be for him to find out his coordinates and post that to a web page but I'd like it to update automatically.
A response with code is not necessary, just a general opinion on methodology/advisability would be appreciated
I would probably give him a webpage to go to that records his position every time he visits. It would be a private URL, and perhaps use some lightweight authentication. For versatility, I'd record the exact position in the database (in case he changes his mind on how it should work later on). However, you could use an external service or another purchased database with zips or city information with lat/lng data, so you could just provide users of the client app with his general vicinity rather than exact location.
The alternative would be to give him an ad hoc app that does the same thing, but putting together that location recording webpage would be a much simpler process. Could be handy for other things, too.
Here's a little writeup about getting location from mobile Safari, just as a reference: http://mobiforge.com/developing/story/location-iphone-web-apps
Why wouldn't you just use google latitude and read out his status?
I think this should really be done as a web page web-app. You can get coordinates from the device through mobile safari and you can skip the app approval process. You can also set it up so it runs fullscreen on his phone and he won't know the difference. You can also put a password on it.
There is a good chance it would not get approved as a regular app.
You can always meta refresh the page to keep it updating.
http://smithsrus.com/gps-geolocation-in-safari-on-iphone-os-3-0/
"Artist" must log in to his application (thus insuring that he want to share his coordinates with your webserver), then you use CLLocationManager to get his coordinates and make a reverse geocoding using Google Maps API to get country and city for given coordinates.
Can't see anything special about it :)
Generally speaking, how does an app like "Around Me" acquire the information it displays?
For example: the restaurants that show up in a list that are near me with the address and distance (I think I get the distance piece) where is this information extracted from? Is it Google or something?
I'm not asking how to implement this (that's over my head!) just get an idea of how it occurs.
Thanks StackOverFlow people.
I haven't seen that specific app, but most such apps either have an embedded database of locations or they dynamically query a server back-end (e.g. using HTTP) to fetch a set of locations near you. They know where you are because the app has access to location services to find out your geographic location.
The iPhone has a GPS unit which gives you your latitude and longitude, which it then sends to a backend server (Say Google Maps) and queries it for, in your case a restaurant. The server responds with a set of locations around you.
I have a few questions about Core Location.
1) Should the user refuse permission for my app to use core location, or core location is unavailable for some reason, is there a fallback? (Device Locale, for example?)
2)Can I cache a device's location for next time? Does Core Location do this itself?
3)I really need the sunset time in the user's area during the mid-spring season and I have a function to do that, once I have the Latitude and Longitude of the device. Perhaps I can just make an assumption about the time based on Locale? (Example: In the US, assume approximately 7:00pm.)
EDIT:
I really am trying to calculate sunset in the users area for an app. Nothing to do with the map. I am considering the following sequence of events:
Check for Core Location availability. If yes, use it and store it in NSUserPreferences. If Core Location is unavailable, go on to the fallbacks.
Check for a stored Location. If it's stored, use it. If not, go on...
Check for the user's chosen time.
1) Strictly speaking, if the user does not allow using CoreLocation or, if permission were given but CoreLocation is not available, there is no other fallback to get the user's location as a latitude, longitude pair. Using the locale may not work in all of the cases. First, it will just give you an approximation which may be way too far from reality. However, it's up to you to judge whether this approximation is ok for your app. Moreover, there are some users using a locale different from the one related to their country. And, you have no guarantee that people travelling abroad will adjust the date/time every time.
2) Core Location caches by default the last location retrieved from the GPS unit. However, for people travelling abroad this cached location will be certainly wrong (even for people travelling just a few miles away), and in general, you should discard the cached value and localize again the user each time. I understand that for people travelling within their country this will not (usually) create huge problems. But it just depends on the country: travelling within Italy will not change the time, but travelling across the US may change the time up to 3 hours.
3) I would suggest to try using Core Location and, in case of problems, simply ask the user to input his/her local time or location (the city should be enough for your purpose). If you choose to ask for the user's location, then you can get the corresponding latitude/longitude pair but this will require a working network connection.
2) From the online docs for CLLocationManager:
The location service returns an initial location as quickly as possible, returning cached information when available.
You can check the CLLocation timestamp to see if it is a cached value or not.
3) If you do decide to use locale for an initial TZ approximation, remember that users travel, and may not reset their locale promptly. You can get the current TZ object with:
[NSTimeZone localTimeZone]