How are you guys , my problem that my flutter app is connected to mysql db , when the user is registered a string with the class name is saved to shared preferences and there is a wall to post some posts on it , is there any way to work with fcm bassed on the shared preferences string ? Like if the user has this string and posted let all users with the same string get notifications i hope i could make it more uderstandable but i dont know how ! Thanks
This sounds like a perfect use-case for using topics to target those messages. Step-wise:
Each device subscribes to the topic based on their class. If they can have multiple classes, they'd subscribe to all topics for those classes.
You then send the message to the correct topic for its class, and FCM will deliver it to all devices subscribed to that topic.
As usual, you will need to perform the actual send operation from a trusted environment, such as your development machine, a server you control, or Cloud Functions.
you will get the token id from the device which you can store to the user table so it will use while giving the notification to every device.
For getting the token :
_firebaseMessaging.getToken().then((String token) {
assert(token != null);
setState(() {
_homeScreenText = "Push Messaging token: $token";
});
print(_homeScreenText);
});
this token variable which you can store to the user table and use it while giving the notification to every device.
Related
Sorry if my question is dumb, I'm new to MassTransit.
My system consists of a server and multiple client devices.
I'd like to send a message from the server to a specific client or to a group of clients.
As far as I understand, IBusControl.Publish sends the message to all subscribers, and IBusControl.Send to the only one subscriber.
How can I achieve this using MassTransit?
My transports are RabbitMQ / Azure Service Bus.
Thanks!
MassTransit implements standard messaging patterns, which aren't MassTransit-specific. Point-to-point, publish-subscribe, invalid message channel, dead letter channel and so on:
You indeed have the choice between sending a message to one consumer using Send and to broadcast messages to all subscribers for that message type by using Publish.
Everything else can be easily done by adding code to consumers:
await bus.Publish(new MyMessage { ReceiverGroup = "group1", ... });
and
public async Task Consume(IContext<MyMessage> context)
{
if (context.Message.ReceiverGroup != myGroup) return;
...
}
I am new to Pinpoint and trying to understand how endpoint/endpointId works in Pinpoint semantics. From the aws doc:
When a user starts a session (for example, by launching your mobile app), your mobile or web application can automatically register (or update) an endpoint with Amazon Pinpoint.
Does that mean each time of the app launching, there is a new endpoint/endpointId? Will it register a new endpoint if the current session ends or the user kill and relaunch the app?
Is there a way I can get the endpoint/endpointId in the app programmatically?
Yes, the endpoint is the same for each unique device, email, etc. It needs to be the same so that Amazon knows where to send push notifications, for example, if you run a targeted campaign. If the user kills and relaunches the app, then the same endpoint is used. This goes for both authenticated and unauthenticated users. Thus, I would have reason to believe that if the current session ends (i.e. the user has to re-authenticate), then they have the same endpoint. This makes sense because every device (the device itself) needs a unique identifier. In order to better answer your question, I have personally tested the below and confirmed:
If one user logs out, and another logs in [on the same device], the endpoint ID remains the same. The purpose of the code below registers a user ID with a specific endpoint. You can also modify the code below to print the endpoint ID, as you requested.
At the top of your AppDelegate, put this, assuming you're using Swift and AWS Cognito for user authentication:
var pinpoint: AWSPinpoint?
... in didFinishLaunching, put this:
self.pinpoint = AWSPinpoint(configuration:AWSPinpointConfiguration.defaultPinpointConfiguration(launchOptions: launchOptions))
if let targetingClient = pinpoint?.targetingClient {
if let username = AppDelegate.defaultUserPool().currentUser()?.username {
let endpoint = targetingClient.currentEndpointProfile()
// Create a user and set its userId property
let user = AWSPinpointEndpointProfileUser()
user.userId = username
// Assign the user to the endpoint
endpoint.user = user
// Update the endpoint with the targeting client
targetingClient.update(endpoint)
print("Assigned user ID \(user.userId ?? "nil") to endpoint \(endpoint.endpointId).\n")
}
}
I have a Line-of-Business (LoB) Windows 8.1 Store application I developed for a client. The client side-loads it on several Windows 10 tablets. They use it in an environment where WiFi is spotty at best and they would like to get some sort of notification inside the app, regardless of what page they are on, notification that will let them know that they've lost connectivity to the network. I have created a method on my Web API that is not hitting the repository (database). Instead, it quickly returns some static information regarding my Web API, such as version, date and time of the invocation and some trademark stuff that I'm required to return. I thought of calling this method at precise intervals of time and when there's no response, assume that the Web API connectivity is lost. In my main page, the first one displayed when the application is started, I have the following stuff in the constructor of my view model:
_webApiStatusTimer = new DispatcherTimer();
_webApiStatusTimer.Tick += OnCheckWebApiStatusEvent;
_webApiStatusTimer.Interval = new TimeSpan(0, 0, 30);
_webApiStatusTimer.Start();
Then, the event handler is implemented like this:
private async void OnCheckWebApiStatusEvent(object sender, object e)
{
// stop the timer
_webApiStatusTimer.Stop();
// refresh the search
var webApiInfo = await _webApiClient.GetWebApiInfo();
// add all returned records in the list
if (webApiInfo == null)
{
var messageDialog = new MessageDialog(#"The application has lost connection with the back-end Web API!");
await messageDialog.ShowAsync();
// restart the timer
_webApiStatusTimer.Start();
}
}
When the Web API connection is lost, I get a nice popup message that informs me that the Web API is no longer available. The problem I have is that after a while, especially if I navigate away from the first page but not necessary, I get an UnauthorizedAccessException in my application.
I use the DispatcherTimer since my understanding is that this is compatible with
UI threads, but obviously, I still do something wrong. Anyone cares to set me on the right path?
Also, if you did something similar and found a much better approach, I'd love to hear about your solution.
Thanks in advance,
Eddie
First, If you are using Windows Store Apps, then you could possibly use a Background task to check poll for the status of the web api instead of putting this responsibility on your view model, its not the viewmodels concern
Second, if you are connecting from your Windows store app to your API then one successful authentication/ authorization for the first time, how and where do you store the token (assuming you are using token authentication). If you are (and ideally you should), is there a timer that you start which is set to the token expiration time? Is your local storage getting flushed somehow and loosing the aurthorization data?
Need more information.
I was able to connect and upload videos using the library but when I deleted the app connection on Vimeo.com (as a test) the app didn't authorize again.
the upload looks like it's working but nothing is uploaded as the app is no longer connected.
I deleted the app on the phone and restarted but it still won't re-authorize the app.
This comes up in the output:
Vimeo upload state : Executing
Vimeo upload state : Finished
Invalid http status code for download task.
And this is in OldVimeoUpload.swift: ( didn't include the actual access code!)
import Foundation
class OldVimeoUpload: VimeoUpload
{
static var VIMEO_ACCESS_TOKEN :String! // = "there's a string of numbers here"
static let sharedInstance = OldVimeoUpload(backgroundSessionIdentifier: "") { () -> String? in
return VIMEO_ACCESS_TOKEN // See README for details on how to obtain and OAuth token
}
// MARK: - Initialization
override init(backgroundSessionIdentifier: String, authTokenBlock: AuthTokenBlock)
{
super.init(backgroundSessionIdentifier: backgroundSessionIdentifier, authTokenBlock: authTokenBlock)
}
}
It looks like the access token number is commented out. I deleted the 2 forward slashes to see if that would fix it but it didn't.
I spoke too soon.
It sounds like you went to developer.vimeo.com and created an auth token. Used it to upload videos. And then went back to developer.vimeo.com and deleted the auth token.
The app / VimeoUpload will not automatically re-authenticated in this situation. You've killed the token and the app cannot request a new one for you. You'll need to create a new auth token and plug it into the app.
If this is not accurate and you're describing a different issue let us know.
If you inspect the error that's thrown from the failing request I'm guessing you'll see it's a 401 unauthorized related to using an invalid token.
Edit:
Disconnecting your app (as described in your comment below) has the same effect as deleting your auth token from developer.vimeo.com.
Also, VimeoUpload accepts a hardcoded auth token (as you see from the README and your code sample). It will not automatically re-authenticate, probably ever.
If you'd like to handle authentication in your app check out VimeoNetworking or VIMNetworking. Either of those libraries can be used to create a variety of authentication flows / scenarios. Still, if a logged in user disconnects or deletes their token, you will need them to deliberately re-authenticate (i.e. you will need to build that flow yourself). In that case, the user has explicitly stated that they don't want the app to be able to access information on their behalf. It would go against our security contract with them to automatically re-authenticate somehow.
Does that make sense?
I've successfully installed and run the Google Drive Quick Start application called DriveCommandLine. I've also adapted it a little to GET file info for one of the files in my Drive account.
What I would like to do now is save the credentials somehow and re-use them without the user having to visit a web page each time to get an authorization code. I have checked out this page with instructions to Retrieve and Use OAuth 2.0 credentials. In order to use the example class (MyClass), I have modified the line in DriveCommandLine where the Credential object is instantiated:
Credential credential = MyClass.getCredentials(code, "");
This results in the following exception being thrown:
java.lang.NullPointerException
at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:187)
at com.google.api.client.json.jackson.JacksonFactory.createJsonParser(JacksonFactory.java:84)
at com.google.api.client.json.JsonFactory.fromInputStream(JsonFactory.java:247)
at com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets.load(GoogleClientSecrets.java:168)
at googledrive.MyClass.getFlow(MyClass.java:145)
at googledrive.MyClass.exchangeCode(MyClass.java:166)
at googledrive.MyClass.getCredentials(MyClass.java:239)
at googledrive.DriveCommandLine.<init>(DriveCommandLine.java:56)
at googledrive.DriveCommandLine.main(DriveCommandLine.java:115)
I've been looking at these APIs (Google Drive and OAuth) for 2 days now and have made very little progress. I'd really appreciate some help with the above error and the problem of getting persistent credentials in general.
This whole structure seems unnecessarily complicated to me. Anybody care to explain why I can't just create a simple Credential object by passing in my Google username and password?
Thanks,
Brian O Carroll, Dublin, Ireland
* Update *
Ok, I've just gotten around the above error and now I have a new one.
The way I got around the first problem was by modifying MyClass.getFlow(). Instead of creating a GoogleClientServices object from a json file, I have used a different version of GoogleAuthorizationCodeFlow.Builder that allows you to enter the client ID and client secret directly as Strings:
flow = new GoogleAuthorizationCodeFlow.Builder(httpTransport, jsonFactory, "<MY CLIENT ID>", "<MY CLIENT SECRET>", SCOPES).setAccessType("offline").setApprovalPrompt("force").build();
The problem I have now is that I get the following error when I try to use flow (GoogleAuthorizationCodeFlow object) to exchange the authorization code for the Credentials object:
An error occurred: com.google.api.client.auth.oauth2.TokenResponseException: 400 Bad Request
{
"error" : "invalid_scope"
}
googledrive.MyClass$CodeExchangeException
at googledrive.MyClass.exchangeCode(MyClass.java:185)
at googledrive.MyClass.getCredentials(MyClass.java:262)
at googledrive.DriveCommandLine.<init>(DriveCommandLine.java:56)
at googledrive.DriveCommandLine.main(DriveCommandLine.java:115)
Is there some other scope I should be using for this? I am currently using the array of scopes provided with MyClass:
private static final List<String> SCOPES = Arrays.asList(
"https://www.googleapis.com/auth/drive.file",
"https://www.googleapis.com/auth/userinfo.email",
"https://www.googleapis.com/auth/userinfo.profile");
Thanks!
I feel your pain. I'm two months in and still getting surprised.
Some of my learnings...
When you request user permissions, specify "offline=true". This will ("sometimes" sic) return a refreshtoken, which is as good as a password with restricted permissions. You can store this and reuse it at any time (until the user revokes it) to fetch an access token.
My feeling is that the Google SDKs are more of a hinderence than a help. One by one, I've stopped using them and now call the REST API directly.
On your last point, you can (just) use the Google clientlogin protocol to access the previous generation of APIs. However this is totally deprecated and will shortly be turned off. OAuth is designed to give fine grained control of authorisation which is intrinsically complex. So although I agree it's complicated, I don't think it's unnecessarily so. We live in a complicated world :-)
Your and mine experiences show that the development community is still in need of a consolidated document and recipes to get this stuff into our rear-view mirrors so we can focus on the task at hand.
Oath2Scopes is imported as follows:
import com.google.api.services.oauth2.Oauth2Scopes;
You need to have the jar file 'google-api-services-oauth2-v2-rev15-1.8.0-beta.jar' in your class path to access that package. It can be downloaded here.
No, I don't know how to get Credentials without having to visit the authorization URL at least once and copy the code. I've modified MyClass to store and retrieve credentials from a database (in my case, it's a simple table that contains userid, accesstoken and refreshtoken). This way I only have to get the authorization code once and once I get the access/refresh tokens, I can reuse them to make a GoogleCredential object. Here's how Imake the GoogleCredential object:
GoogleCredential credential = new GoogleCredential.Builder().setJsonFactory(jsonFactory)
.setTransport(httpTransport).setClientSecrets(clientid, clientsecret).build();
credential.setAccessToken(accessToken);
credential.setRefreshToken(refreshToken);
Just enter your clientid, clientsecret, accessToken and refreshToken above.
I don't really have a whole lot of time to separate and tidy up my entire code to post it up here but if you're still having problems, let me know and I'll see what I can do. Although, you are effectively asking a blind man for directions. My understanding of this whole system is very sketchy!
Cheers,
Brian
Ok, I've finally solved the second problem above and I'm finally getting a working GoogleCredential object with an access token and a refresh token.
I kept trying to solve the scopes problem by modifying the list of scopes in MyClass (the one that manages credentials). In the end I needed to adjust the scopes in my modified version of DriveCommandLine (the one that's originally used to get an authorization code). I added 2 scopes from Oauth2Scopes:
GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
httpTransport, jsonFactory, CLIENT_ID, CLIENT_SECRET,
Arrays.asList(DriveScopes.DRIVE, Oauth2Scopes.USERINFO_EMAIL, Oauth2Scopes.USERINFO_PROFILE))
.setAccessType("offline").setApprovalPrompt("force").build();
Adding the scopes for user information allowed me to get the userid later in MyClass. I can now use the userid to store the credentials in a database for re-use (without having to get the user to go to a URL each time). I also set the access type to "offline" as suggested by pinoyyid.