Flutter How to import backendless_sdk messaging module?

Question

I am following this article How to Create a Chat App with Backendless SDK for Flutter

import 'package:flutter/material.dart';
import 'package:backendless_sdk/backendless_sdk.dart'; 
import 'package:backendless_sdk/src/modules/modules.dart';

There is a error:

"Target of URI doesn't exist: 'package:backendless_sdk/src/modules/modules.dart'."

The modules.dart import is required for Backendless.Messaging, but without the import there is an error:

The getter 'Messaging' isn't defined for the type 'Backendless'.


  void initListeners() async {
    Channel channel = await Backendless.Messaging.subscribe("myChannel");
    channel.addMessageListener(onMessageReceived);
  }

pub spec.yaml

dependencies:
  flutter:
    sdk: flutter
  backendless_sdk: ^1.1.8

How can I import the Messaging module?

score 1 · Accepted Answer · edited Jun 20 '20 at 09:12

1

You should change from:

await Backendless.Messaging.subscribe

in to:

await Backendless.messaging.subscribe
                  ^
                  |
           small "m" here

Versions

I checked backendless_sdk: ^0.0.2 (from tutorial) and backendless_sdk: ^1.1.8 (newest one), and in both cases this field was named messaging (lowercase).

Class `Backendless`

backendless_sdk-1.1.8/lib/src/backendless.dart:

edited Jun 20 '20 at 09:12

Community

1
1

answered May 15 '20 at 22:00

Boken

4,825
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Indeed, the article was written for a pre-release version of the SDK. The documentation uses lower-case "m": https://backendless.com/docs/flutter/pubsub_establish_subscription.html – Mark Piller May 16 '20 at 01:08

score 0 · Answer 2 · answered May 15 '20 at 20:36

0

It look like you are missing the installation step.

From the terminal: Run flutter pub get.

OR

From Android Studio/IntelliJ: Click Packages get in the action ribbon at the top of pubspec.yaml.
From VS Code: Click Get Packages located in right side of the action ribbon at the top of pubspec.yaml.

answered May 15 '20 at 20:36

Haniel Baez

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Remove `import 'package:backendless_sdk/src/modules/modules.dart';` – Haniel Baez May 15 '20 at 21:17
Don't import implementation files from another package. Target of URI doesn't exist: 'package:backendless_sdk/src/modules/modules.dart'. Try creating the file referenced by the URI, or Try using a URI for a file that does exist – dak May 15 '20 at 21:18
import 'package:backendless_sdk/src/modules/modules.dart' is required for Backendless.Messaging.subscribe("myChannel"); – dak May 15 '20 at 21:19
There is not reference about it on https://pub.dev/packages/backendless_sdk, no even in the article you are following. – Haniel Baez May 15 '20 at 21:25
This is a link to the source code for the article: https://github.com/4lfant/messaging_app/blob/master/lib/main.dart – dak May 15 '20 at 21:32
The article that is using `backendless_sdk: ^0.0.2` from May 13, 2019, and you are using `backendless_sdk: ^1.1.8`, please use as a reference https://pub.dev/documentation/backendless_sdk/latest/ – Haniel Baez May 15 '20 at 21:44

score 0 · Answer 3 · answered May 15 '20 at 21:51

0

I do not see any references to modules.dart in the article you mentioned. You need to import backendless_sdk and also include the socket.io dependency:

dependencies {
   implementation ('io.socket:socket.io-client:1.0.0') { 
     // excluding org.json which is provided by Android 
     exclude group: 'org.json', module: 'json' 
   }
}

answered May 15 '20 at 21:51

Mark Piller

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This is a link to the source code for the article: github.com/4lfant/messaging_app/blob/master/lib/main.dart – dak May 15 '20 at 21:59

Flutter How to import backendless_sdk messaging module?

3 Answers3

Versions

Class Backendless

Class `Backendless`