Why does eclipse GWT designer for uibinder generate exception because of uifield

Question

I'm fairly new to GWT App development, so the learning curve hasn't really straightened out a whole lot yet; however, it seems to me the following shouldn't be causing a problem.

I'm working from example code off the net to learn more. I'm using Eclipse Kepler and GWT designer 3.1.2.

The App works, minus a small error in the styling references in the Login.ui.xml which I had fixed but reversed out trying to find how I broke this.

I'm getting the following error when I use design mode on Login.ui.xml.

Unable to create @UiField(provided=true).
You are attempting to use @UiField(provided=true) for (com.learn.client.LoginResources) res, however GWT Designer was not able to create instance of requested object. This can be caused by one of the following reasons: 

Type is interface and you've not provided *.wbp-component.xml description with UiBinder.createInstance script. 
GWT Designer attempted to use shortest constructor of type (such as default constructor), but it caused exception. 


Show stack trace. 
Hide stack trace. 

Stack trace:
org.eclipse.wb.internal.core.utils.exception.DesignerException: 4508 (Unable to create @UiField(provided=true).). com.learn.client.LoginResources res
    at com.google.gdt.eclipse.designer.uibinder.parser.UiBinderParser.createProvidedField(UiBinderParser.java:291)
    at com.google.gdt.eclipse.designer.uibinder.parser.UiBinderParser$2.invoke(UiBinderParser.java:182)
    at com.sun.proxy.$Proxy670.provideField(Unknown Source)

My sources are as follows:

Login.ui.xml
<!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent">
<ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder"
    xmlns:gwt="urn:import:com.google.gwt.user.client.ui"
    xmlns:res="urn:with:com.learn.client.LoginResources">
    <ui:with field="res" type="com.learn.client.LoginResources" />
   <gwt:HTMLPanel>
      <div align="center">
         <gwt:VerticalPanel res:styleName="style.background">
            <gwt:Label text="Login" res:styleName="style.blackText" />
            <gwt:TextBox ui:field="loginBox" res:styleName="style.box" />
            <gwt:Label text="Password" res:styleName="style.blackText" />
            <gwt:PasswordTextBox ui:field="passwordBox"  res:styleName="style.box" />
            <gwt:HorizontalPanel verticalAlignment="middle">
               <gwt:Button ui:field="buttonSubmit" text="Submit" res:styleName="style.loginButton" />
               <gwt:CheckBox ui:field="myCheckBox" />
               <gwt:Label ui:field="myLabel" text="Remember me" res:styleName="style.blackText" />
            </gwt:HorizontalPanel>
            <gwt:Label ui:field="completionLabel1" res:styleName="style.blackText" />
            <gwt:Label ui:field="completionLabel2" res:styleName="style.blackText" />
         </gwt:VerticalPanel>
      </div>
   </gwt:HTMLPanel>
</ui:UiBinder> 

Login.java
public class Login extends Composite {
       private static LoginUiBinder uiBinder = GWT.create(LoginUiBinder.class);
       private Boolean tooShort = false;

       @UiField(provided=true) TextBox loginBox;
       @UiField TextBox passwordBox;
       @UiField Label completionLabel1;
       @UiField Label completionLabel2;
       @UiField(provided=true) final LoginResources res;

       /*
       * @UiTemplate is not mandatory but allows multiple XML templates
       * to be used for the same widget. 
       * Default file loaded will be <class-name>.ui.xml
       */
       @UiTemplate("Login.ui.xml")
        interface LoginUiBinder extends UiBinder<Widget, Login> {
       }

       public Login() {
           loginBox = new TextBox();
          this.res = GWT.create(LoginResources.class);
          res.style().ensureInjected();
          initWidget(uiBinder.createAndBindUi(this));
       }
        :
        :
        Handlers
        :
        :
    }

nResources.java
public interface LoginResources extends ClientBundle {
       /**
       * Sample CssResource.
       */
       public interface MyCss extends CssResource {
          String blackText();

          String redText();

          String loginButton();

          String box();

          String background();
       }

       @Source("LoginStyle.css")
       MyCss style();
}

LoginStyle.css
.blackText {
   font-family: Arial, Sans-serif;
   color: #000000;
   font-size: 11px;
   text-align: left;
}

.redText {
   font-family: Arial, Sans-serif;
   color: #ff0000;
   font-size: 11px;
   text-align: left;
}

.loginButton {
   border: 1px solid #3399DD;
   color: #FFFFFF;
   background: #555555;
   font-size: 11px;
   font-weight: bold;
   margin: 0 5px 0 0;
   padding: 4px 10px 5px;
   text-shadow: 0 -1px 0 #3399DD;
}

.box {
   border: 1px solid #AACCEE;
   display: block;
   font-size: 12px;
   margin: 0 0 5px;
   padding: 3px;
   width: 203px;
}

.background {
   background-color: #999999;
   border: 1px none transparent;
   color: #000000;
   font-size: 11px;
   margin-left: -8px;
   margin-top: 5px;
   padding: 6px;
}

Manolo Carrasco Moñino · Accepted Answer · 2013-10-16T19:49:08.737

1

It seems designer does not support provided fields when they need a generator.

I would include the LoginStyle.css stuff in the Login.ui.xml

Something like this:

<ui:UiBinder xmlns:ui='urn:ui:com.google.gwt.uibinder'
    xmlns:g='urn:import:com.google.gwt.user.client.ui'> 
    <ui:style>
          .container {
          }
        </ui:style>
    <g:FlowPanel ui:field="container" addStyleNames="{style.container}">
    </g:FlowPanel>
</ui:UiBinder>

edited Oct 16 '13 at 19:49

answered Oct 16 '13 at 15:42

Manolo Carrasco Moñino

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I thought about doing just that; however, I can not find an example that I can get to work correctly. Additionally, I gave up on that pursuit when I read in the GWT documentation that that method was depreciated. Do you have any example of that method that works? I tried the following in my Login.ui.xml. , with the css in the same folder as the ui.xml – Lee Oct 16 '13 at 16:56
Sorry, I missed the field name as part of the ui:style in my last comment. Here is a clip of my code using your recommendation. It doesn't work either......

– Lee Oct 16 '13 at 17:46
Edited my response. BTW I would not trust so much in designer, it is ok to create initial screens, but once the developing is advanced, and you introduce more code in your classes, you can suffer issues. – Manolo Carrasco Moñino Oct 16 '13 at 19:51
I think I follow you about the advanced code may produce more issues. WYSIWYG can only get you so far, then rubber meet the road and you have start programming. The problem I find with your recommendation is that placing the style code directly in the ui.xml equals circumventing the purpose and advantages of a css file. I think I'll go with my original solution and simply accept that the gui editing tool will no longer be useful. Everything works fine on the final output of the app, I just can use the gui tool. Thanks anyway. – Lee Oct 17 '13 at 20:20

Why does eclipse GWT designer for uibinder generate exception because of uifield

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