I have been working on a maps application (iphone) originally I had my annotations set up to pull XML from google using their Places API. I'm having 3 issues.
For my annotation info, I was going
off of an example from Zen
(http://www.zen-sign.com/finding-business-listings-and-displaying-with-mapkit-part-1/
) and he has it set up to do it by
keyword, which wasn't really
necessary for me ( but I used it
anyway just to get a feel for
getting the annotations) in the
parser header he has:
-(void) getBusinessListingsByKeyword:(NSString*)keyword atLat:(float)lat atLng:(float)lng;
and in the the viewdidload of his
view controller
[locationsMap findLocationsByKeyword:#"Apple" ];
I'm not sure how to move from the
keyword parse version used in zen to
something that just does it
automatically (in the parser object- without the viewdidload in a different view controller if possible).
Any advice on what to read/watch or
sample code much appreciated
For places information
Google isn't the only kid on the
block and XML I hear comes in second
to JSON. So I wanted to know what
the best practice was for map
annotations made from business
information: JSON or XML?
The other issue I was having was
only getting 10 annotations (I want
to get 50 or more). So on top of
your advice on using XML or JSON.
How to I increase the amount of
annotations I'm getting.
Sorry for making this 3 parts but again any tutorials (text of video) would be very helpful. (So far I've watched hegarty from Stanford, Larson from MATC)
First
Don't know what you mean by automaticaly. But if you want to launch the map on users current location here you have two methods you can use:
-(IBAction)goToCurrentLocation{
CLLocation *location = [[CLLocation alloc]
initWithLatitude:myMap.userLocation.coordinate.latitude
longitude:myMap.userLocation.coordinate.longitude];
[self setCurrentLocation:location];
}
- (void)setCurrentLocation:(CLLocation *)location {
MKCoordinateRegion region = {{0.0f, 0.0f}, {0.0f, 0.0f}};
region.center = location.coordinate;
region.span.longitudeDelta = 0.15f;
region.span.latitudeDelta = 0.15f;
[self.myMap setRegion:region animated:YES];
}
Second. I don't know what are the best practicies but I used json with this jeson parser for my app ijustmadelove
Three. There is no problem in getting more then 10 annotations on the map. You have to have an error or a limitation in your code.
Related
I am using google api V3 in my iOS App,
I requested to google api direction service, by http GET method, I got a very large json response, I got many alternate routes from origin to destination, now I want to show the route of each alternative on map, how should I done this ? is there any need to integrate google sdk in iOS, or can i use webView only, please help me, and suggest the simplest way.
Thanks in advance
you do not need to include any google SDK to draw the route over map. Look at the following classes.
MKPolyline
MKPolyLineview
The google map api Direction service will give you the legs(coordinates) to draw the route between two specific points.
As you already have the json response from the Direction api now you have to parse the json and get all the legs point from the json to create Coordinate array.
Jsonkit for parsing
These points may be or mostly encripted. How to decode the Google Directions API polylines field into lat long points in objective-C for iPhone?
If you have the coordinates array then first you have to create a CLLocationCoordinate2D array like following:
CLLocationCoordinate2D *pointArr = malloc(sizeof(CLLocationCoordinate2D) * [your_CoordinateArray count]);
for(int i = 0; i < [your_CoordinateArray count]; i++){
pointArr[i] = [your_CoordinateArray objectAtIndex:i];
}
Then you have to add the polyline to your map
MKPolyline *line = [MKPolyline polylineWithCoordinates:pointArr count:[your_CoordinateArray count]];
if (nil != line)
{
[your_Map addOverlay:line];
}
Then you have to implement the following map delegate:
- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay
{
MKOverlayView* overlayView = nil;
lineView = [[MKPolylineView alloc] initWithPolyline:overlay];// lineView is an ivar, object of MKPolylineView
lineView.fillColor = [UIColor greenColor];
lineView.strokeColor = [UIColor greenColor];
lineView.lineWidth = 10.0;
lineView.alpha = 0.9;
overlayView = lineView;
return overlayView;
}
Now, if you want to show two different routes between two points then you have to create two different array of coordinates and apply the above method for both Arrays
Hope this will help you.
There is no need per say to integrate google sdk and you can simply use webView since I believe the webView gives you alternative views, but the user interface is much cleaner in the SDK than online. But at this moment, I don't believe the SDK allows other apps to show the alternative routes from what I've used of the new SDK. The code in maps.google.com is now considerably different from that in
the API and has access to different services. In particular, it has a large external module, mod_suggest.js, that doesn't exist in the API. But you may be able to implement it by
1) Throw the request at maps.google.com, and let it do the suggestions,
i.e. open a new browser window and pass it something like
http://www.google.com/maps?f=d&source=s_d&saddr=Jurong+West,+Singapore&da
ddr=Ang+Mo+Kio,+Singapore&hl=en
2) Just display the normal route and the avoid highways route.
3) Try to guess sensible waypoints to add in the middle of he route that
might lead to reasonable alternatives. That's not easy unless you have a
database of highways or highway intersections, and can look for such an
intersection that's somewhere between your start and end points (for
some approximate value of "between").
There may be problems using lat/lng coordinates for the waypoints,
particularly if there's a dual carriageway involved. If the coordinates
are for a point on the wrong carriageway, GDirections will drive a
considerable distance out of your way so that you visit the wrong side
of the road. But even using street names you may well get strange kinks
near the waypoints, like this:
from: Jurong West, Singapore to: Ayer Rajah Expy singapore to: Ang Mo
Kio, Singapore
Perhaps the only way to really deal with that is to include points on
both sides of a dual carriageway, and well clear of roads that cross
underneath or overhead, and then try to filter out the ones that are
silly.
Consider these examples
from: Jurong West, Singapore to: 1.32558,103.740764 to: Ang Mo Kio,
Singapore
from: Jurong West, Singapore to: 1.32582,103.740764 to: Ang Mo Kio,
Singapore
One of those adds 7 minutes to the trip by a complicated excursion to
visit the wrong side of the road.
Writing code to filter out silly routes isn't easy. As a first
approximation, you could discard routes that have estimated times that
are more than, say, 10% longer than the initial route. And you can also
compare the durations for pairs of points on opposite sides of a dual
carriageway and always discard the slower one.
Writing code to discard duplicate routes isn't easy either. For example,
a point on Bukit Timah Expy or Kranji Expy might create a route that's a
duplicate of Google's Seletar Expy suggestion.
You might want to look at: http://www.geocodezip.com/example_geo2.asp?waypts=yes&addr1=Jurong+West,+Singapore&addr2=Ang+Mo+Kio,+Singapore&waypt=Ayer+Rajah+Expy+singapore&geocode=1&geocode=2
But that may not be a legal implementation since the API does not allow it. Hope this helps.
i'm drawing polyline on MapView using "google direction API" and getting success in it.But the thing is that it draws straight line between two locations(with their longitude and latitude).I don't know how to draw line effectively like shown by google maps,when we click "get directions" between two locations.
I suggest taking a look at an SDK like CloudMade, this makes it very easy to implement custom maps and route's, you'll be able to draw a route between two locations within about 10 minutes of installing the SDK. Here is a quick example to get you started if you go down this route, excuse the pun.
CLLocationCoordinate2D initLocation;
initLocation.longitude = -0.127523;
initLocation.latitude = 51.51383;
CLLocationCoordinate2D destination;
destination.longitude = -0.125;
destination.latitude = 51;
TokenManager* tokenManager = [[TokenManager alloc] initWithApikey:#"YOUR API KEY"];
CMRoutingManager *routeManager = [[CMRoutingManager alloc] initWithMapView:mapView tokenManager:tokenManager];
[routeManager findRouteFrom:initLocation to:destination onVehicle:CMVehicleWalking];
You can find more information here in the documentation. Another alternative would be to use route-me which would allow you to choose from the following map sources:
OpenStreetMap, Microsoft VirtualEarth, CloudMade, OpenAerialMap, OpenCycleMap, SpatialCloud, and two offline, database-backed formats (DBMap and MBTiles)
Although personally i do not have any experience with route-me, so can't point you in the right direction to get started.
If you are adement on sticking with MKMapView, this blog post will get your started in the right direction.
I am currently using the following code:
UIApplication *app = [UIApplication sharedApplication];
[app openURL:[NSURL URLWithString:#"http://maps.google.com/maps?saddr=Current%20Location&daddr=Chicago"]];
It works perfectly fine for opening up the directions in the google maps App. If I wanted to do this EXACT same thing, only within the App itself, how would I do it? I currently have a viewController set up that has an instance of MKMapView, but it shows the entire world. Everything is working fine but as soon as I try to read the Apple Documentation on Annotations my head starts to spin.
The annotations part is reasonably straightforward once you wrap your head around it, but the path-drawing part is a tremendous hassle. I do it in one of my apps and it took a lot of work to not just draw the lines and keep them scaled and such, but more importantly do it in a speedy and memory-efficient way if the user specifies a route that has literally hundreds of steps (cross-country avoiding highways, for example).
Unless the routing is the focus of your app, I wouldn't bother. If you still really want to I'll go back and review the code and provide some pointers. Just be forewarned that there's a surprisingly lot to it.
I am going to assume that you're doing a lookup for an address and displaying that in your app. You can use the Geocoder API to do a lookup with bounds (or without). I'm using this NSString format: NSString *geocoderURLFormat = #"http://maps.googleapis.com/maps/api/geocode/json?address=%#&bounds=%#&sensor=true".
The callback from this call will return a suggested viewport for the location -- southwest and northeast lat/long values. Using these, you can set the region of the MKMapView object like this:
CLLocationCoordinate2D coord;
coord.latitude = location.latitude;
coord.longitude = location.longitude;
MKCoordinateSpan span;
span.latitudeDelta = location.swLatitude > location.neLatitude ? location.swLatitude - location.neLatitude : location.neLatitude - location.swLatitude;
span.longitudeDelta = location.swLongitude > location.neLongitude ? location.swLongitude - location.neLongitude : location.neLongitude - location.swLongitude;
MKCoordinateRegion region;
region.span = span;
region.center = coord;
[mapView setRegion:region animated:YES];
Note that I'm still a little fuzzy on the latitudeDelta and longitudeDelta values of MKCoordinateSpan, hence the ugliness of the code. And the location variable that I'm using is constructed from the results of the call to Geocoder.
Hope this helps!
I keep getting this randomly when I run my gps app I'm building. It doesn't happen everytime, and the coordinates passed in are always valid (i nslog them). Is there documentation for these somewhere?
EDIT:
CLLocationCoordinate2D coord = CLLocationCoordinate2DMake(locManager.location.coordinate.latitude, locManager.location.coordinate.longitude);
geocoder1 = [[MKReverseGeocoder alloc] initWithCoordinate:coord];
geocoder1.delegate = self;
[geocoder1 start];
and then about half the time it returns an error. I tried releasing and re-assigning the geocoder if there was an error, but that didn't help. Only thing that did was restarting the app.
In "MKTypes.h" in the MapKit framework, the following is defined:
Error constants for the Map Kit framework.
enum MKErrorCode {
MKErrorUnknown = 1,
MKErrorServerFailure,
MKErrorLoadingThrottled,
MKErrorPlacemarkNotFound,
};
...
MKErrorPlacemarkNotFound
The specified placemark could not be found.
This sounds like you are referencing some unknown placemark in your code? Or it could be that Google doesn't have a name for the position you are passing - however valid the coordinates may be.
I've met and solved this issue recently. In my case, when Apple Map cannot find any result for a query, it sometimes will just throw this this "MKErrorDomain = 4" error. So I ended up just treat this as "result not found".
It was painstaking to find this out, MapKit needs a better Error handling system.
I've been hitting this error repeatedly, and was unable to figure out how to make it stop; but I finally found an end-run around the whole issue that works quite well, and only takes a little more work: Don't use Apple's MKReverseGeocoder at all -- instead, directly call Google's reverse-geocoding API (this is apparently the same service that MKReverseGeocoder does behind the scenes). You can get back either JSON or XML (your preference), which you will then have to parse, but that isn't too hard.
For example, since my app is using ASIHTTPRequest, this is what it looks like (although this would also be easy to do with do with Apple's native APIs such as NSURLConnection):
#pragma mark -
#pragma mark CLLocationManagerDelegate
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
// Be careful: My code is passing sensor=true, because I got the lat/long
// from the iPhone's location services, but if you are passing in a lat/long
// that was obtained by some other means, you must pass sensor=false.
NSString* urlStr = [NSString stringWithFormat:
#"http://maps.googleapis.com/maps/api/geocode/xml?latlng=%f,%f&sensor=true",
newLocation.coordinate.latitude, newLocation.coordinate.longitude];
NSURL* url = [NSURL URLWithString:urlStr];
self.reverseGeocoderRequest = [ASIHTTPRequest requestWithURL:url];
self.reverseGeocoderRequest.delegate = self;
[self.reverseGeocoderRequest startAsynchronous];
}
By the way, Google's API has rules, just like Apple's does. Make sure you read the docs, especially regarding quotas.
I'm running into the same thing (the exact same code randomly fails sometimes) and I think I've found the answer. From Apple's developer docs: "Each Map Kit application has a limited amount of reverse geocoding capacity, so it is to your advantage to use reverse geocode requests sparingly."
So my theory is, we're getting rate-limited... since no other variables are changing (i.e. my code isn't changing, I'm running it on the simulator so the location of the device isn't changing, etc.) I think this must be the only remaining reason.
I just got done with a lot of research on this problem and it seems to be outside of our hands. I checked the developer forums as well as all around Stack and elsewhere and no one has a solution other than using a different service. There is a pretty good thread at https://devforums.apple.com/message/154126 on the subject.
Some people find the error after a certain time, I just find it to be out for a while and then comes back. I looked at the "Current Address" sample code and I couldn't see how I might have messed up. I ran the sample code and sure enough, it was NSLogging errors instead of returning a location.
This link has some code using Google's reverse geocoder: http://www.iphonedevsdk.com/forum/iphone-sdk-development/31883-pbrequestererrordomain-errors-reverse-geocoding.html#post155793
Actually, I am running into this problem as well. Code is extremely compact
//1. ask map for current coords
CLLocationCoordinate2D userLocation;
userLocation.latitude = [[_theMapView.userLocation location] coordinate].latitude;
userLocation.longitude = [[_theMapView.userLocation location] coordinate].longitude;
NSLog(#"%f, %f",userLocation.latitude,userLocation.longitude);
//2. reverse geocode coords
MKReverseGeocoder *reverseGeocoder = [[MKReverseGeocoder alloc]
initWithCoordinate:userLocation];
[reverseGeocoder setDelegate:self];
[reverseGeocoder start];
and later simply NSLog the error in the fail delegate method. It works the first time or two, then stops working
if the user zooms out on a MKMapView, i want MKAnnotations which are near to each other automatically grouped into one "group" annotation.
if the user zooms back in, the "group" annotation should be split again to the unique/original annotations.
apple does this already in the iOS 4 Photos.app
is there a common, "predefined" way to do this?
Its normal working with more than 1500 annotations on the map:
-(void)mapView:(MKMapView *)mapView_ regionDidChangeAnimated:(BOOL)animated
{
NSMutableSet * coordSet = [[NSMutableSet alloc] init];
for(id<MKAnnotation> an in mapView_.annotations)
{
if([an isKindOfClass:[MKUserLocation class]])
continue;
CGPoint point = [mapView_ convertCoordinate:an.coordinate toPointToView:nil];
CGPoint roundedPoint;
roundedPoint.x = roundf(point.x/10)*10;
roundedPoint.y = roundf(point.y/10)*10;
NSValue * value = [NSValue valueWithCGPoint:roundedPoint];
MKAnnotationView * av = [mapView_ viewForAnnotation:an];
if([coordSet containsObject:value])
{
av.hidden = YES;
}
else
{
[coordSet addObject:value];
av.hidden = NO;
}
}
[coordSet release];
}
That's a brilliant idea. I'm working on a similar app, I hope you don't mind if I als implement the concept :).
To answer your question to the best of my own ability, no, I don't think there is a predefined way to do this.
The best way I can think of to do it (after looking at the iOS4 photos app), is to make use of the mapView:regionDidChangeAnimated: delegate method. Any time the user scrolls/zooms, this method will be called.
Inside that method, you could have some quick geometry math to determine whether your points are "close enough" to consider merging. Once they're "merged", you'd remove one or both annotations, and put another annotation back in the same place that is a reference to both (you could make an AnnotationCluster class very easily that could conform to MKAnnotation but also hold an NSArray of annotations, and also contain methods for "breaking out" or "absorbing" other annotations and/or AnnotationCluster instances, etc).
When I say "quick geometry math", I mean the distance of the two points relative to the span of the map, and taking their relative distance as a percentage of the span of the whole map.
Where that would get tricky is if you had hundreds of annotations, as I can't off-hand think of a good way to implement that w/o a double loop.
What do you reckon?
This project does something interesting. Though, have a look at reported issues before changing too many things in your code. Because it could be not good enough for your needs yet.
I personnaly ended up implementing this