Grid row rendering?

[DarekKay]

I have a standard grid containing some domain objects (which have String/Integer/Boolean values) with a PropertyAccess to load those values automatically. This works very good and all values are rendered by the corresponding object values.

Now I want to format/render my row by the object's boolean value. Assuming it's true, all corresponding cells should be rendered as <b>value</b> - and normally otherwise. The only way I've found so far was to create my column:

ColumnConfig c = new  ColumnConfig(new IdentityValueProvider<MyObject>(), ....);

and to define the Cell:

column.setCell(new AbstractCell<MyObject>()
        {
            @Override
            public void render(com.google.gwt.cell.client.Cell.Context context, MyObject value,
                    SafeHtmlBuilder sb)
            {
                if (value.isActive())
                    sb.appendHtmlConstant("<b>" + value.getName() + "</b>");
                else 
                    sb.appendEscaped(value.getName());
            }
        });

Having several columns I need to implement a different cell for each of them, containing almost the same code except the value.getName() part - seems pretty redundant to me. Is there no other way to achieve this?

Using Firebug, I just added style="font-weight: bold" to the <tr> (or <table>) element containing my desired row. Is there any way to step into the row rendering process and add my style depending on the underlying object's value?

[sven]

Having several columns I need to implement a different cell for each of them, containing almost the same code except the value.getName() part - seems pretty redundant to me. Is there no other way to achieve this?

You could create a base class that has all your logic. You also do not have to use a IdentityValueProvider and so you would not need different cells. Instead of using AbstractCell you can also use TextCell with a custom SafeHtmlRenderer

[DarekKay]

Thank you for your reply.

The problem is: such a custom cell renderer has no knowledge about other cells or object values (which is understandable) - and that's the point: I want to set a different style/renderer depending on values from another column. Maybe that's what you mean by "create a base class that has all your logic" - but how exactly would that look like?

[robferguson]

Hi,

You can access other columns in your custom render() method. Construct your grid as normal (with a store and column model).

For example:

  @Inject
  public AbstractAdministrationView() {
    super();

    this.setGrid(new ContextAreaGrid(new ContextAreaModelListStore(), getContextAreaColumModel()));
    this.grid.setSize(CONTEXT_AREA_WIDTH, CONTEXT_AREA_HEIGHT);

    // add the Grid to the View's layout container
    this.panel.add(this.grid, new VerticalLayoutData(1, 1)); 

    ...

  }

Then access your model (row) in the render method:

  public ColumnModel<ContextAreaModel> getContextAreaColumModel() {

    ...

    ColumnConfig<ContextAreaModel, String> column1DisplayNameColumnConfig = new ColumnConfig<ContextAreaModel, String>(property.column1DisplayName(),
            ContextAreaGrid.DISPLAY_NAME_COLUMN_WIDTH, "");
    column1DisplayNameColumnConfig.setCell(new AbstractSafeHtmlCell<String>(SimpleSafeHtmlRenderer.getInstance()) {
      @Override
      protected void render(Context context, SafeHtml data, SafeHtmlBuilder sb) {

        if (data == null) {
          return;
        }

        ContextAreaModel model = (ContextAreaModel) getGrid().getStore().get(context.getIndex());

        sb.appendHtmlConstant("<span>"  + "<b>" + data.asString() + "</b><br />" + model.getColumn1Description() + "</span>");
      }
    });

   ...

    List<ColumnConfig<ContextAreaModel, ?>> columnConfigList = new ArrayList<ColumnConfig<ContextAreaModel, ?>>();
    columnConfigList.add(column1IconColumnConfig);
    columnConfigList.add(column1DisplayNameColumnConfig);
    columnConfigList.add(column2IconColumnConfig);
    columnConfigList.add(column2DisplayNameColumnConfig);

    ColumnModel<ContextAreaModel> columnModel = new ColumnModel<ContextAreaModel>(columnConfigList);

    return columnModel;
  }

The context passed to your render() method includes the index of the row (context.getIndex())

Cheers
Rob

http://code.google.com/p/gwt-cx/

[DarekKay]

I think this is GXT 2 code, but nevertheless it led me to the solution

Big Thanks!