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mqtt_client.dart: "Null check operator used on a null value" for authenticationManager in connect() method. #15

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Merged
merged 1 commit into from
Oct 7, 2021
Merged

mqtt_client.dart: "Null check operator used on a null value" for authenticationManager in connect() method. #15

merged 1 commit into from
Oct 7, 2021

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@stijn1989
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@stijn1989 stijn1989 commented Oct 7, 2021

When an active connection to the MQTT server is lost. The _disconnect() method sets the authenticationManager to null.
When you call connect() again on the client, you get an exception "Null check operator used on a null value".
With this extra line of code, the authenticationManager has an object for sure.

Class MQTT {
  ....
  
  Future<MqttConnectionStatus?> connect() async {
    return client.connect(user, pass);
  }
  
  ...
}

...
FloatingActionButton(
  child: Icon(Icons.message),
  onPressed: () async {
      await mqtt.connect(); //<- here you get the exception when pressing the button when the MQTT is back online.
      mqtt.sub();
  }
)
....

@stijn1989
Update mqtt_client.dart
8aa13e5 
When an active connection to the MQTT server is lost. The _disconnect() method sets the authenticationManager to null. 
When you call connect() again on the client, you get an exception "Null check operator used on a null value". 
With this extra line of code, the authenticationManager has an object for sure.
@shamblett shamblett merged commit 7d80ba0 into shamblett:master Oct 7, 2021
@shamblett
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shamblett commented Oct 7, 2021

Yes good catch, client updated and re published at version 3.1.1

@gawie-kellerman gawie-kellerman mentioned this pull request Dec 9, 2022
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@Extenda-TimRoberson Extenda-TimRoberson mentioned this pull request Feb 17, 2023
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@stijn1989 @shamblett