GWT's i18n interface null b/c hidden by isDesignTime

[allioop70]

We have a base class that all our "panels" derive from, because we are using internationalization, the i18n constants class is used by all our "panels" so we have added it to the base class.

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public class BaseWidget extends Composite
{
  public static i18nConstants ouri18nConstants = null;

  public BaseWidget()
  {
    if (ouri18nConstants == null)
    {
      if (!isDesignTime())
      {
        ouri18nConstants = (i18nConstants)   GWT.create(i18nConstants.class);
      }
    }
  }
}


This is all fine and good, except that when you go to use the Design View of Designer, ouri18nConstants is null, so the page doesn't render and the log shows NullPointerException for each call to a method in the i18nConstants class.

If we don't use the isDesignTime method, the pages won't render either b/c Designer can't instantiate the i18nConstants class in Design View.

Example: In a derived class:

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Label panelHeaderLabel = new Label(ouri18nConstants.header());


Is there a way around this problem?

Thanks!

[Eric Clayberg]

You need to follow the pattern shown in our Internationalization docs and assign your constants directly to a static final field.

Here's an example...

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import com.google.gwt.i18n.client.Constants;

public interface AppConstants extends Constants {
   String button_text();
   String button2_text();
}

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#GWT variable: CONSTANTS
#Wed May 23 11:16:15 MSD 2007
button_text=New Button
button2_text=My second button

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import com.google.gwt.core.client.GWT;
import com.google.gwt.user.client.ui.AbsolutePanel;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.Composite;
import com.mycompany.tutorial.client.AppConstants;

public class BaseWidget extends Composite {
   protected static final AppConstants CONSTANTS = (AppConstants) GWT.create(AppConstants.class);
   private AbsolutePanel absolutePanel;
   public BaseWidget() {
      {
         absolutePanel = new AbsolutePanel();
         initWidget(absolutePanel);
         absolutePanel.setSize("100px", "100px");
         {
            final Button button = new Button();
            absolutePanel.add(button, 156, 158);
            button.setText(CONSTANTS.button_text());
         }
      }
   }
   public AbsolutePanel getAbsolutePanel() {
      return absolutePanel;
   }
}

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import com.google.gwt.user.client.ui.Button;

public class MyPanel extends BaseWidget {
   public MyPanel() {
      {
         final Button button = new Button();
         getAbsolutePanel().add(button, 28, 38);
         button.setText(CONSTANTS.button2_text());
      }
   }
}

Also make sure that you are using the latest GWT Designer build.

[allioop70]

I believe I mentioned in my post that assigning it directly was what we tried first and it didn't work. Almost exactly like the code you posted above. Designer wouldn't draw the screens because it wouldn't instantiate the constants, as soon as we wrapped it with the isDesignTime method, the screens would draw in Designer, but when we used the constants class, it stopped drawing again because the constants class is null at design time.

This is what we had originally in our base class:

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public static final i18nConstants ouri18nConstants =
      (i18nConstants) GWT.create(i18nConstants.class);


What we have now was posted above.

We are using that latest stable build, 1.7.1.

You need to follow the pattern shown in our Internationalization docs and assign your constants directly to a static final field. <SNIP>
Also make sure that you are using the latest GWT Designer build.

[allioop70]

Okay, so I found that the Designer generated i18n properties file adds the following line that GWT itself doesn't use

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#GWT variable: ouri18nConstants

So, after adding that line to our properties file, I am now seeing all my properties in Designers Externalize Strings dialog.

However, I still cannot use our pre-existing key/value pairs, but if I add a new one, using the externalize wizard, it works.

What is Designer doing behind the scenes that only key/value pairs externalized by Designer work?

BTW, I still have the instantiation of ouri18nConstants wrapped with isDesignTime b/c it does not work otherwise.

[Eric Clayberg]

Are you saying that the example I posted above does not work on your end?

Here are screen shots of what it looks like on my end...



Please give my example a try and let me know if it works. If it works, then post (or e-mail) a detailed example (using the same pattern) that does not work.

There must be some difference that accounts for this working on my end and failing onyour end.