I am trying to add this response data to a zip object and later calling the createZip() method to download file as a zip file. Problem is my file getting downloaded first and the response is coming back. If I try to run the function again then right file is getting downloaded because in the previous API call I already got the response data.
Can anyone help me with this. I am new to angular and don't know how to use async/await properly.
zipFile = new JSZip();
exportIcsReportInJSONFormat() {
this.icsService.getICSReport()
.subscribe(response => {
console.log("JSONFile",response)
this.jsonFile = response;
this.zipFile.file("ics-report_.json", response, {binary:true});
});
To create zip file and download.
createZip() {
this.zipFile.generateAsync({type:"blob"})
.then(function(content) {
saveAs(content, "example.zip");
});
}
You can use the async/await pattern with Promises, something like this:
zipFile = new JSZip();
async mapZip() {
try {
var response = await this.exportIcsReportInJSONFormat();
console.log("JSONFile", response)
this.jsonFile = response;
this.zipFile.file("ics-report_.json", response, { binary: true });
var content = await this.zipFile.generateAsync({ type: "blob" });
saveAs(content, "example.zip");
}
catch {
...
}
}
exportIcsReportInJSONFormat() {
this.icsService.getICSReport().toPromise();
}
I'm trying to detect whether Google Maps app is installed on iOS, and if so, launch it, if not, launch Apple Maps. Here is what I have so far, but on my phone with Google Maps installed, it isn't detecting it and launching appropriately.
Any ideas?
import 'package:url_launcher/url_launcher.dart';
_launchMaps() async {
String googleUrl =
'comgooglemaps://?center=${trip.origLocationObj.lat},${trip.origLocationObj.lon}';
String appleUrl =
'https://maps.apple.com/?sll=${trip.origLocationObj.lat},${trip.origLocationObj.lon}';
if (await canLaunch("comgooglemaps://")) {
print('launching com googleUrl');
await launch(googleUrl);
} else if (await canLaunch(appleUrl)) {
print('launching apple url');
await launch(appleUrl);
} else {
throw 'Could not launch url';
}
}
I pulled the url scheme from here: How would I be able to open google maps when I press a button in my app?
you can install the packege url_launcher and use the code down below:
import 'package:url_launcher/url_launcher.dart';
class MapUtils {
MapUtils._();
static Future<void> openMap(double latitude, double longitude) async {
String googleUrl = 'https://www.google.com/maps/search/?api=1&query=$latitude,$longitude';
if (await canLaunch(googleUrl)) {
await launch(googleUrl);
} else {
throw 'Could not open the map.';
}
}
}
Now you can open google maps in your app just call this method:
MapUtils.openMap(-3.823216,-38.481700);
I found my issue: this needs to be in the plist file. The code in the question above is fine. (The SO answer referenced in the question only mentioned the "comgooglemaps" string.)
<key>LSApplicationQueriesSchemes</key>
<array>
<string>googlechromes</string>
<string>comgooglemaps</string>
</array>
Docs: https://developers.google.com/maps/documentation/ios-sdk/start#step_7_declare_the_url_schemes_used_by_the_api
Do it this way
Full code is given below
static void navigateTo(double lat, double lng) async {
var uri = Uri.parse("google.navigation:q=$lat,$lng&mode=d");
if (await canLaunch(uri.toString())) {
await launch(uri.toString());
} else {
throw 'Could not launch ${uri.toString()}';
}
}
1) in pubspec.yaml
dependencies:
flutter:
sdk: flutter
...
url_launcher: ^5.7.8
2) Import wherever you want to use
import 'package:url_launcher/url_launcher.dart';
3) final you call
onPressed: () {
navigateTo(location.lat, location.lng);
},
If you don't have the actual latlong, you can simply pass an address to Google Maps.
void launchMap(String address) async {
String query = Uri.encodeComponent(address);
String googleUrl = "https://www.google.com/maps/search/?api=1&query=$query";
if (await canLaunch(googleUrl)) {
await launch(googleUrl);
}
}
Of course, the more information you have in the address, the more accurate the search will be. Exactly the same as looking for something on the actual Google Maps page or app.
By the way, you need to url-encode the address before adding it to the URL, to support special characters like spaces. It's only needed for iOS, but hey, we want to develop for all environments out there.
using url launcher
in yaml file: url_launcher: ^5.0.2 last
then you can use this method to open google maps centered to the provided lat and long
more info to maps intent from docs [here][2]
launchMap({String lat = "47.6", String long = "-122.3"}) async{
var mapSchema = 'geo:$lat,$long';
if (await canLaunch(mapSchema)) {
await launch(mapSchema);
} else {
throw 'Could not launch $mapSchema';
}
}
If you want to navigate with directions you can just create a url with source and destination co-ordinates and other coordinates to add as stops.
Steps:
Install url_launcher plugin
write a code like below.
_launchURL(String url) async {
if (await canLaunch(url)) {
await launch(url);
} else {
throw 'Could not launch $url';
}
}
const url ='https://www.google.com/maps/dir/?api=1&origin=43.7967876,-79.5331616&destination=43.5184049,-79.8473993&waypoints=43.1941283,-79.59179|43.7991083,-79.5339667|43.8387033,-79.3453417|43.836424,-79.3024487&travelmode=driving&dir_action=navigate';
_launchURL(url);
static Future<void> openMap(BuildContext context, double lat, double lng) async {
String url = '';
String urlAppleMaps = '';
if (Platform.isAndroid) {
url = 'https://www.google.com/maps/search/?api=1&query=$lat,$lng';
if (await canLaunchUrl(Uri.parse(url))) {
await launchUrl(Uri.parse(url));
} else {
throw 'Could not launch $url';
}
} else {
urlAppleMaps = 'https://maps.apple.com/?q=$lat,$lng';
url = 'comgooglemaps://?saddr=&daddr=$lat,$lng&directionsmode=driving';
if (await canLaunchUrl(Uri.parse(url))) {
await launchUrl(Uri.parse(url));
} else if (await canLaunchUrl(Uri.parse(urlAppleMaps))) {
await launchUrl(Uri.parse(urlAppleMaps));
} else {
throw 'Could not launch $url';
}
}
}
import 'package:url_launcher/url_launcher.dart';
static void launchMapsUrl(
sourceLatitude,
sourceLongitude,
destinationLatitude,
destinationLongitude) async {
String mapOptions = [
'saddr=$sourceLatitude,$sourceLongitude',
'daddr=$destinationLatitude,$destinationLongitude',
'dir_action=navigate'
].join('&');
final url = 'https://www.google.com/maps?$mapOptions';
if (await canLaunch(url)) {
await launch(url);
} else {
throw 'Could not launch $url';
} }
Here you can use this function directly and pass the required parameters and also import this package https://pub.dev/packages/url_launcher/
As follow-up to Roc Boronat's post, the following code can be used for launching the platform specific map application.
Future<void> launchMapUrl(String address) async {
String encodedAddress = Uri.encodeComponent(address);
String googleMapUrl = "https://www.google.com/maps/search/?api=1&query=$encodedAddress";
String appleMapUrl = "http://maps.apple.com/?q=$encodedAddress";
if (Platform.isAndroid) {
try {
if (await canLaunch(googleMapUrl)) {
await launch(googleMapUrl);
}
} catch (error) {
throw("Cannot launch Google map");
}
}
if (Platform.isIOS) {
try {
if (await canLaunch(appleMapUrl)) {
await launch(appleMapUrl);
}
} catch (error) {
throw("Cannot launch Apple map");
}
}
For more information regarding the query parameters in Apple Maps URL, please visit this link.
Edit (7th Aug, 2022): This code will work upto version 6.0.20 of the url_launcher plugin. I could not get it to work after this version as I was getting an ERR_UNKNOWN_URL_SCHEME error when trying to launch Google Maps using canLaunchUrl and launchUrl methods using the versions of the plugin above 6.0.20 and 6.0.20. It works only with the deprecated methods (canLaunch and launch). Just a heads up if anyone wants to try this code snippet.
with 'url_launcher 6.1.0' + physical address instead of lat & lon,
void _pushMap(String address) async {
String query = Uri.encodeComponent(address);
String googleUrl = "google.navigation:q=$query";
Uri googleUri = Uri.parse(googleUrl);
if (await canLaunchUrl(googleUri)) {
await launchUrl(googleUri);
}
}
This will send an implicit Intent to open related apps including google maps.
Haven't tested on iOS devices.
tldr: I think there's an error in the library and canLaunch sometimes returns false even if the url can be launched.
I was trying to open a google maps link (https://goo.gl/maps/mHGzrGUhUHrQByAm8) the same way I do for another link from my app, but for whatever reason canLaunch always returned false.
So now I launch in a try catch block to make sure it doesn't crash my app, and it's working.
try {
launch(url);
} catch (error, stack) {
// log error
}
you can install the packege url_launcher and use the code down below:
This is the latest code as per
url_launcher: 6.1.6
canLaunch();
launch(); these methods has been deprecated now.
class GoogleMapUtils {
GoogleMapUtils._();
static Future<void> openMapApp(double latitude, double longitude) async {
Uri googleUrl = Uri.parse('https://www.google.com/maps/search/?api=1&query=$latitude,$longitude');
if (await canLaunchUrl(googleUrl)) {
await launchUrl(googleUrl);
} else {
throw 'Unable open the map.';
}
}
}
Use plugin:
intent: ^1.4.0
Try the following code:
static void navigateTo(double lat, double lng) async {
var uri = Uri.parse("google.navigation:q=$lat,$lng&mode=c");
android_intent.Intent()
..setAction(android_action.Action.ACTION_VIEW)
..setData(uri)
..setPackage("com.google.android.apps.maps")
..startActivity().catchError((e) => print(e));
}
Note: Only works on Android devices
Install url_launcher package
use the below function
void launchMap() async {
Uri googleUrl = Uri.parse('https://www.google.com/maps/search/?api=1&query=Googleplex');
if (await canLaunchUrl(googleUrl)) {
await launchUrl(googleUrl, mode:LaunchMode.externalApplication);
}
}
Using url luncher with navigation open by default.
Sample code - if app installed it will open in app otherwise open in any browser
///launch map
Future<void> openMap(double latitude, double longitude) async {
String mapUrl = '';
if (Platform.isIOS) {
mapUrl =
'https://maps.apple.com/?daddr=$latitude,$longitude';
} else {
mapUrl =
'https://www.google.com/maps/dir/?api=1&destination=$latitude,$longitude&travelmode=driving';
}
if (await canLaunchUrl(Uri.parse(mapUrl))) {
await launchUrl(Uri.parse(mapUrl),mode: LaunchMode.externalApplication);
} else {
throw 'Could not open the map.';
}
}
if you like to open google map in apple devices add this code in info.plist
<key>LSApplicationQueriesSchemes</key>
<array>
<string>googlechromes</string>
<string>comgooglemaps</string>
</array>
<key>LSApplicationQueriesSchemes</key>
For other queries
Google url params example
https://www.google.com/maps/dir/?api=1
&origin=$latitude,$longitude
&destination=$latitude,$longitude
&travelmode=driving
&dir_action=navigate
Apple
q= query
saddr = starting point for directions
daddr = destination point for directions
dirflg = The transport type
I have an wp8 app using PeriodicTask background Agent.
The task update the information of multiple live tiles,
using POST Client to get title and image url from my server to update the live tile.
Background agent works just fine in debugging and releasing mode. When the .xap file was deployed into my device using XAPDeployement tool, the background Agent also works perfectly.
However, it won't work after submitted to wp app store, no matter it's beta version or not.
If the app is downloaded from store, the background agent has never worked, and it is blocked by system after a few minutes.
How come it goes wrong since the XAP files are the same?
part of code:
public static Task<string> jsonPostClientTask(Dictionary<string, object> parameters, string url)
{
var results = new TaskCompletionSource<string>();
PostClient proxy = new PostClient(parameters);
try
{
proxy.DownloadStringCompleted += (sender, e) =>
{
if (e.Error == null)
{
string response = e.Result.ToString();
results.TrySetResult(response);
}
else
{
results.TrySetResult("");
results.TrySetException(e.Error);
}
};
proxy.DownloadStringAsync(new Uri(url));
}
catch
{
results.TrySetResult("");
}
return results.Task;
}
ScheduledAgent class:
protected override void OnInvoke(ScheduledTask task)
{
foreach (var tile in tileList)
{
string dataString = jsonPostClientTask(parameters, url);
//update tile in used
FlipTileData tileData = new FlipTileData()
{
BackContent = "string content",
WideBackContent = "string back content",
BackBackgroundImage = new Uri("http://xxxx.xxx/xxx.png", UriKind.RelativeOrAbsolute),
WideBackBackgroundImage = new Uri("http://xxxx.xxx/xxx.png", UriKind.RelativeOrAbsolute),
};
ShellTile primaryTile = ShellTile.ActiveTiles.First();
if (primaryTile != null)
primaryTile.Update(tileData);
}
}
I have the following code. The async call never returns anything. Even for google.com.
try
{
using (
var client = new HttpClient()) {
var response = client.GetAsync("http://www.google.com");
Debug.WriteLine("Coming here1"+response.Result.IsSuccessStatusCode);
if (response.Result.IsSuccessStatusCode)
{
// by calling .Result you are performing a synchronous call
Debug.WriteLine("Coming here1");
var responseContent = response.Result.Content;
// by calling .Result you are synchronously reading the result
string responseString = responseContent.ReadAsStringAsync().Result;
//Console.WriteLine(responseString);
}
else { Debug.WriteLine("else"); }
}
}
catch(Exception e)
{
Debug.WriteLine(e.ToString());
}
}
Try This
try{
WebClient wc = new WebClient();
wc.DownloadStringCompleted+= (sender,args) => {
Debug.WriteLine(args.results);
};
wc.DownloadStringAsync(new Uri(#"http://www.Google.com",UriKind.RelativeOrAbsolute));
}
catch(Exception e){ Debug.WriteLine(e.Message); }
You don't appear to be awaiting your Async call.
Try changing var response = client.GetAsync("http://www.google.com"); to var response = await client.GetAsync("http://www.google.com");
Remember to mark your method as async.
you're also blocking on your async call ReadAsStringAsync().Result. As with client.GetAsync, make sure to await the call instead of blocking with Result. This blog post speaks a bit on the topic.
Read up a bit on async/await. You'll love it once you get the hang of it.
I am trying to get a reference to a response stream before its complete in windows phone 8.
In other .Net platforms you can do
HttpWebRequest httpRequest = (HttpWebRequest)WebRequest.Create(myUri);
WebResponse subscribeWebResponse = null;
Stream subscribeStream = null;
subscribeWebResponse = httpRequest.GetResponse();
subscribeStream = subscribeWebResponse.GetResponseStream();
For the purpose of creating Portable class libraries I've used the HttpClientLibrary from nuget.
This Adds ref to extensions assembly Microsoft.Net.Http
this allows me to return the async request at the time the headers have been read instead of waiting for the content transfer to be complete with
var clientResponse = await httpClient.SendAsync(requestmessage, HttpCompletionOption.ResponseHeadersRead);
The problem I'm having is that in windows phone 8 it doesn't work correctly, and still awaits the completion of the content stream to return.
Additionally
await httpWebRequest.BeginGetResponse(callback, request)
has the same behavior as these async methods are actually waiting for the completion of the web's response to continue execution.
So, is there any way to achieve the returning the response/stream at the point that i have received the response headers without Microsoft.Http.Net package?
Even if it has to be a Windows Phone 8 Platform Specific Solution?
Possibly an extension of HttpWebRequest?
From what I can tell, ResponseHeadersRead works on the WP8 emulator as it does on the desktop.
I installed the Win8 SDK. Created a windows phone app. I added this code to the MainPage ctor. This demonstrates a very rudimentary long polling example.
var client = new HttpClient();
var request = new HttpRequestMessage()
{
RequestUri = new Uri("http://oak:1001/longpolling")
};
client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, new CancellationToken())
.ContinueWith((t) =>
{
var response = t.Result;
response.Content.ReadAsStreamAsync()
.ContinueWith(s =>
{
var st = s.Result;
while (true)
{
var message= ReadNextMessage(st);
}
});
});
}
private static string ReadNextMessage(Stream stream)
{
int chr = 0;
string output = "";
while (chr != 10)
{
chr = stream.ReadByte();
output += Convert.ToChar(chr);
}
return output;
}
On my host dev machine I have a web api with a controller that looks like this...
public class LongPollingController : ApiController
{
public HttpResponseMessage Get()
{
Thread.Sleep(2000);
var content = new PushStreamContent( (s,c,t) =>
{
int i = 0;
while (true)
{
try
{
var message = String.Format("The current count is {0} " + Environment.NewLine, i++);
var buffer = Encoding.UTF8.GetBytes(message);
s.Write(buffer, 0, buffer.Length);
}
catch (IOException exception)
{
s.Close();
return;
}
Thread.Sleep(1000);
}
});
return new HttpResponseMessage(HttpStatusCode.OK)
{
RequestMessage = Request,
Content = content
};
}
}
So here's the deal. I would say that what you want to do is not possible, due to platform limitations... But SignalR has a WP client and is able to manage it. So it seems to me you have two options:
1) Dig into the SignalR source code to see how they do it (I'm on my phone right now so I can't provide a link).
UPDATE: Here is the link. They do some pretty neat tricks, like setting the Timeout to -1 for long-running clients. I think you should definitely use the techniques here.
OR
2) You can move whatever you're doing over to SignalR, which would gain the benefit of having a robust infrastructure and being cross-platform compatible.
HTH