Cannot find symbol error in extension

Extensions
1

From 2 days, I am trying to fix this problem but could not do.
I get error that cannot find symbol in one line, I have done all the necessary imports but the same :worried:

Every line goes right but this line doesn't : -

NotificationManager notificationManager = (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);

My imports in extension

import android.content.Context;
import android.app.Application;
And other imports...

And here is the error code : -

NotificationManager notificationManager = (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);
[javac]                                                                     ^
[javac]   symbol:   method getApplicationContext()

Please help me if possible, I am still learning java by creating extensions for AppInventor...
Thanks.

2

Use container.$context() to get context.

1 Like
3 
container.$context()

Is there any imports? Or I can use it directly?

4

No special imports required just make sure ComponentContainer is there

1 Like
5

I will PM you my code, can you just check what's wrong?

6

If possible paste the code here so that it can help anyone else in the future

2 Likes
7

I think you should send it here, it will help others in the community to learn too. and maybe someone else can help you in the same

1 Like
8 
package com.extension.blabla.xoma;


import com.google.appinventor.components.annotations.DesignerComponent;
import com.google.appinventor.components.annotations.SimpleObject;
import com.google.appinventor.components.annotations.SimpleFunction;
import com.google.appinventor.components.annotations.SimpleEvent;
import com.google.appinventor.components.annotations.SimpleProperty;
import com.google.appinventor.components.common.ComponentCategory;
import com.google.appinventor.components.runtime.AndroidNonvisibleComponent;
import com.google.appinventor.components.runtime.AndroidViewComponent;
import com.google.appinventor.components.runtime.ComponentContainer;
import com.google.appinventor.components.runtime.EventDispatcher;

//External

import android.content.Context;
import android.app.NotificationManager;
import android.app.Application;

@DesignerComponent(version = 1,
    category = ComponentCategory.EXTENSION,
    description = "BlaBla",
    nonVisible = true,
    iconName = "https://community.appinventor.mit.edu/user_avatar/community.appinventor.mit.edu/kumaraswamy_b.g/32/13770_2.png")

@SimpleObject(external = true)

public class ExtensionTemplate extends AndroidNonvisibleComponent {

public ExtensionTemplate(ComponentContainer container) {
    super(container.$form());
}

@SimpleFunction(description = "BlaBla")
public void BlaBla() {
    NotificationManager notificationManager = (NotificationManager) container.$context().getSystemService(Context.NOTIFICATION_SERVICE);
   //Some activity...
}
}

Yes you can see my code, @Souvik_Bera & @Alaqmar_Bohori I have just problem with that line only.

9

The problem is obvious. From where are you accessing the container variable ? You need to declare container variable in the extension class then assign the value from the constructor.

public class ExtensionTemplate extends AndroidNonvisibleComponent {

private ComponentContainer container;

public ExtensionTemplate(ComponentContainer container) {
    super(container.$form());
    this.container = container;
}
1 Like
10

AndroidNonvisibleComponent has form as a protected field which serves as a context, so form.getSystemService(...) should work.

2 Likes
11

Thanks @Souvik_Bera & @ewpatton now it's working :grinning:

12

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